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Saquinavir

Medically reviewed by Drugs.com. Last updated on Sep 4, 2020.

Pronunciation

(sa KWIN a veer)

Index Terms

  • Fortovase
  • Saquinavir Mesylate
  • SQV

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral:

Invirase: 200 mg [DSC]

Tablet, Oral:

Invirase: 500 mg

Brand Names: U.S.

  • Invirase

Pharmacologic Category

  • Antiretroviral, Protease Inhibitor (Anti-HIV)

Pharmacology

Binds to the site of HIV-1 protease activity and inhibits cleavage of viral Gag-Pol polyprotein precursors into individual functional proteins required for infectious HIV. This results in the formation of immature, noninfectious viral particles.

Absorption

Poor; increased with high-fat meal

Distribution

Vd: 700 L; does not distribute into CSF; partitions into tissues

Metabolism

Extensively hepatic via CYP3A4 to inactive mono- and dihydroxylated metabolites; extensive first-pass effect

Excretion

Feces (81% to 88%), urine (1% to 3%) within 5 days

Clearance: Children: Significantly higher than adults

Half-Life Elimination

Serum: 1 to 2 hours

Protein Binding

Plasma: ~98%

Special Populations: Hepatic Function Impairment

Approximately 30% reduction in saquinavir exposure in patients with moderate hepatic impairment.

Use: Labeled Indications

HIV-1 infection, treatment: Treatment of HIV-1 infection in adults (>16 years of age) in combination with ritonavir and other antiretroviral agents. Note: Saquinavir is not recommended as a component of initial therapy for the treatment of HIV (HHS [adult] 2019).

Contraindications

Hypersensitivity (eg, anaphylactic reaction, Stevens-Johnson syndrome) to saquinavir, saquinavir mesylate, or any component of the formulation; congenital QT prolongation, refractory hypokalemia or hypomagnesemia, concomitant use of other medications that both increase saquinavir plasma concentrations and prolong the QT interval; complete AV block (without implanted ventricular pacemaker) or patients at high risk of complete AV block; severe hepatic impairment; coadministration of saquinavir/ritonavir with CYP3A substrates (eg, alfuzosin, amiodarone, atazanavir, bepridil, chlorpromazine, cisapride, clarithromycin, clozapine, dasatinib, disopyramide, dofetilide, ergot derivatives [dihydroergotamine, ergonovine, ergotamine, methylergonovine], erythromycin, flecainide, halofantrine, haloperidol, lidocaine [systemic], lovastatin, lurasidone, midazolam [oral], pentamidine, phenothiazines, pimozide, propafenone, quinidine, quinine, rifampin, rilpivirine [concomitant use or when switching to saquinavir/ritonavir without a ≥2-week washout period], sertindole, sildenafil [when used for pulmonary artery hypertension {eg, Revatio}], simvastatin, sunitinib, tacrolimus, thioridazine, trazodone, triazolam, ziprasidone).

Canadian labeling: Additional contraindications (not in US labeling): Concurrent use with quetiapine, procainamide, sotalol, astemizole, or terfenadine; concurrent use with medications that both increase saquinavir plasma concentrations and prolong the PR interval; acquired QT prolongation

Dosing: Adult

Note: Invirase 200 mg capsules have been discontinued in the United States for more than 1 year.

Note: ECG should be done prior to starting therapy; do not initiate therapy if pretreatment QT interval ≥450 msec. Saquinavir should always be used with concomitant ritonavir; cobicistat is not interchangeable with ritonavir to increase systemic exposure.

HIV-1 infection, treatment: Oral: Note: Saquinavir is not recommended as a component of initial therapy for the treatment of HIV (HHS [adult] 2019).

Usual dosage: 1 g twice daily given in combination with ritonavir 100 mg twice daily. For patients already taking ritonavir 100 mg twice daily as part of their antiretroviral regimen, no additional ritonavir is needed.

Treatment-naive patients or patients switching from a regimen containing delavirdine. Note: Patients with recent exposure (without washout) to a ritonavir or non-nucleoside reverse transcriptase inhibitor-based regimen (not including delavirdine or rilpivirine) may receive usual initial dosing (ie, saquinavir 1 g twice daily in combination with ritonavir 100 mg twice daily).

Initial: Saquinavir 500 mg twice daily given in combination with ritonavir 100 mg twice daily for 7 days.

Maintenance: Saquinavir 1 g twice daily given in combination with ritonavir 100 mg twice daily.

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Invirase 200 mg capsules have been discontinued in the US for >1 year.

Note: ECG should be done prior to starting therapy; do not initiate therapy if pretreatment QT interval >450 msec or if there is a diagnosis of long QT syndrome. Saquinavir must only be used in regimens that include ritonavir "booster doses" so that adequate saquinavir serum concentrations are attained; do not use without ritonavir booster doses.

HIV-1 Infection, treatment: Use in combination with other antiretroviral agents.

Infants and Children <2 years: Not approved for use; appropriate dose is unknown.

Children ≥2 years and Adolescents <16 years: Treatment-experienced, ritonavir-boosted regimen: Limited data available (HHS [pediatric] 2016): Oral:

5 kg to <15 kg: Saquinavir 50 mg/kg/dose twice daily plus ritonavir 3 mg/kg/dose twice daily

15 kg to <40 kg: Saquinavir 50 mg/kg/dose (maximum dose: 1,000 mg/dose) twice daily plus ritonavir 2.5 mg/kg/dose twice daily

≥40 kg: Saquinavir 1000 mg plus ritonavir 100 mg twice daily

Adolescents ≥16 years: Limited data available for adolescents 16 years of age (HHS [pediatric] 2016): Oral: 1,000 mg twice daily given in combination with ritonavir 100 mg twice daily. For patients already taking ritonavir 100 mg twice daily as part of their antiretroviral regimen, no additional ritonavir is needed.

Treatment-naive patients or patients switching from a regimen containing delavirdine or rilpivirine: Adolescents >16 years: Note: Patients with recent exposure (without washout) to a ritonavir or non-nucleoside reverse transcriptase inhibitor-based regimen (not including delavirdine or rilpivirine) may receive usual initial dosing (ie, saquinavir 1,000 mg twice daily in combination with ritonavir 100 mg twice daily).

Initial: Saquinavir 500 mg twice daily given in combination with ritonavir 100 mg twice daily for 7 days

Maintenance: Saquinavir 1,000 mg twice daily given in combination with ritonavir 100 mg twice daily

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Administration

Oral: Administer saquinavir and ritonavir at the same time and within 2 hours after a full meal. Patients unable to swallow capsules may open capsules and mix contents with 15 mL of syrup (or sorbitol if diabetic or glucose intolerant) or with 3 teaspoons of jam. Mixture should be stirred for 30 to 60 seconds and then administered entirely. Suspension should be at room temperature prior to administration. Do not crush tablets.

Dietary Considerations

Take within 2 hours after a meal. Product contains lactose.

Storage

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).

Drug Interactions

Abacavir: Protease Inhibitors may decrease the serum concentration of Abacavir. Monitor therapy

Abemaciclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Abemaciclib. Management: In patients taking abemaciclib at a dose of 200 mg or 150 mg twice daily, reduce the dose to 100 mg twice daily when combined with strong CYP3A4 inhibitors. In patients taking abemaciclib 100 mg twice daily, decrease the dose to 50 mg twice daily. Consider therapy modification

Acalabrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Acalabrutinib. Avoid combination

Ado-Trastuzumab Emtansine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ado-Trastuzumab Emtansine. Specifically, strong CYP3A4 inhibitors may increase concentrations of the cytotoxic DM1 component. Management: Avoid concomitant use of ado-trastuzumab emtansine and strong CYP3A4 inhibitors when possible. Consider alternatives that do not inhibit CYP3A4 or consider administering after CYP3A4 inhibitor discontinuation. Monitor for toxicities if combined. Consider therapy modification

Afatinib: Saquinavir may increase the serum concentration of Afatinib. Management: Monitor for signs and symptoms of afatinib toxicity when these agents are combined. Consider administering saquinavir simultaneously with, or after, the dose of afatinib. If the combination is not tolerated, consider reducing the afatinib dose by 10 mg. Monitor therapy

Alfentanil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alfentanil. Management: If use of alfentanil and strong CYP3A4 inhibitors is necessary, consider dosage reduction of alfentanil until stable drug effects are achieved. Frequently monitor patients for respiratory depression and sedation when these agents are combined. Consider therapy modification

Alfuzosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alfuzosin. Avoid combination

Alitretinoin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alitretinoin (Systemic). Management: Consider reducing the alitretinoin dose to 10 mg when used together with strong CYP3A4 inhibitors. Monitor for increased alitretinoin effects/toxicities if combined with a strong CYP3A4 inhibitor. Consider therapy modification

Almotriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Almotriptan. Management: Limit initial almotriptan dose to 6.25 mg and maximum dose to 12.5 mg in any 24-period when used with a strong CYP3A4 inhibitor. Avoid concurrent use in patients with impaired hepatic or renal function. Consider therapy modification

Alosetron: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alosetron. Monitor therapy

ALPRAZolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ALPRAZolam. Management: Consider using an alternative agent that is less likely to interact. If combined, monitor for increased therapeutic/toxic effects of alprazolam if combined with a strong CYP3A4 inhibitor. Consider therapy modification

Amiodarone: Saquinavir may enhance the QTc-prolonging effect of Amiodarone. Saquinavir may increase the serum concentration of Amiodarone. Avoid combination

Amisulpride (Oral): May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk). Monitor therapy

AmLODIPine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of AmLODIPine. Monitor therapy

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Antipsychotic Agents (Phenothiazines): May enhance the arrhythmogenic effect of Saquinavir. Avoid combination

Apixaban: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Apixaban. Monitor therapy

Aprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Aprepitant. Avoid combination

ARIPiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ARIPiprazole. Management: Aripiprazole dose reductions are required for indications other than major depressive disorder. Dose reductions vary based on formulation, CYP2D6 genotype, and use of CYP2D6 inhibitors. See full interaction monograph for details. Consider therapy modification

ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of ARIPiprazole Lauroxil. Management: Decrease aripiprazole lauroxil dose to next lower strength if used with strong CYP3A4 inhibitors for over 14 days. No dose adjustment needed if using the lowest dose (441 mg). Max dose is 441 mg in CYP2D6 PMs or if also taking strong CYP2D6 inhibitors. Consider therapy modification

Astemizole: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Astemizole. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Astemizole. Avoid combination

Asunaprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Asunaprevir. Avoid combination

Atazanavir: Saquinavir may increase the serum concentration of Atazanavir. Atazanavir may increase the serum concentration of Saquinavir. Avoid combination

AtorvaSTATin: Protease Inhibitors may increase the serum concentration of AtorvaSTATin. Management: Limit atorvastatin dose: 20 mg/day with darunavir/ritonavir, fosamprenavir, fosamprenavir/ritonavir, and saquinavir/ritonavir; 40 mg/day with nelfinavir. Use lowest dose possible with lopinavir/ritonavir. Avoid atorvastatin with tipranavir/ritonavir. Consider therapy modification

Avanafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avanafil. Avoid combination

Avapritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avapritinib. Avoid combination

Axitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Axitinib. Management: Avoid concurrent use of axitinib with any strong CYP3A inhibitor whenever possible. If a strong CYP3A inhibitor must be used with axitinib, a 50% axitinib dose reduction is recommended. Consider therapy modification

Barnidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Barnidipine. Avoid combination

Bedaquiline: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Bedaquiline. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Bedaquiline. Management: Consider alternatives to this drug combination and avoid use for more than 14 days. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Benperidol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benperidol. Monitor therapy

Benzhydrocodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benzhydrocodone. Specifically, the concentration of hydrocodone may be increased. Monitor therapy

Betamethasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Ophthalmic). Monitor therapy

Betamethasone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Systemic). Monitor therapy

Bictegravir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bictegravir. Monitor therapy

Bitter Orange: May increase the serum concentration of Saquinavir. Monitor therapy

Blonanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Blonanserin. Avoid combination

Bortezomib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bortezomib. Monitor therapy

Bosentan: Protease Inhibitors may increase the serum concentration of Bosentan. Management: Dose adjustment of bosentan and increased monitoring for bosentan toxicities is necessary when these agents are combined. See full drug interaction monograph for details. Consider therapy modification

Bosutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bosutinib. Avoid combination

Brentuximab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Monitor therapy

Brexpiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brexpiprazole. Management: Reduce brexpiprazole dose 50% with strong CYP3A4 inhibitors; reduce to 25% of usual if used with both a strong CYP3A4 inhibitor and a CYP2D6 inhibitor in patients not being treated for MDD, or strong CYP3A4 inhibitor used in a CYP2D6 poor metabolizer. Consider therapy modification

Brigatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with strong CYP3A4 inhibitors when possible. If combination cannot be avoided, reduce the brigatinib dose by approximately 50%, rounding to the nearest tablet strength (ie, from 180 mg to 90 mg, or from 90 mg to 60 mg). Consider therapy modification

Bromperidol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bromperidol. Monitor therapy

Budesonide (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Nasal). Monitor therapy

Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Oral Inhalation). Monitor therapy

Budesonide (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Systemic). Management: Avoid the concomitant use of CYP3A4 inhibitors and oral budesonide. If patients receive both budesonide and a strong CYP3A4 inhibitor, they should be closely monitored for signs and symptoms of corticosteroid excess. Consider therapy modification

Budesonide (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Topical). Avoid combination

Buprenorphine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Buprenorphine. Monitor therapy

BusPIRone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of BusPIRone. Management: Limit the buspirone dose to 2.5 mg daily and monitor patients for increased buspirone effects/toxicities if combined with strong CYP3A4 inhibitors. Consider therapy modification

Cabazitaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabazitaxel. Management: Concurrent use of cabazitaxel with strong inhibitors of CYP3A4 should be avoided when possible. If such a combination must be used, consider a 25% reduction in the cabazitaxel dose. Consider therapy modification

Cabozantinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabozantinib. Management: Avoid use of a strong CYP3A4 inhibitor with cabozantinib if possible. If combined, decrease cabozantinib capsules (Cometriq) by 40 mg from previous dose or decrease cabozantinib tablets (Cabometyx) by 20 mg from previous dose. Consider therapy modification

Calcifediol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Calcifediol. Monitor therapy

Calcium Channel Blockers (Nondihydropyridine): Protease Inhibitors may decrease the metabolism of Calcium Channel Blockers (Nondihydropyridine). Increased serum concentrations of the calcium channel blocker may increase risk of AV nodal blockade. Management: Avoid concurrent use when possible. If used, monitor for CCB toxicity. The manufacturer of atazanavir recommends a 50% dose reduction for diltiazem be considered. Saquinavir, tipranavir, and darunavir/cobicistat use with bepridil is contraindicated. Consider therapy modification

Cannabidiol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabidiol. Monitor therapy

Cannabis: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Monitor therapy

Capmatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Capmatinib. Monitor therapy

Cariprazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cariprazine. Management: Decrease cariprazine dose 50% (4.5 mg to 1.5 mg or 3 mg; 1.5 mg to 1.5 mg every other day) if starting a strong CYP3A4 inhibitor. If on a strong CYP3A4 inhibitor, start cariprazine at 1.5 mg day 1, 0 mg day 2, then 1.5 mg daily. May increase to 3 mg daily Consider therapy modification

Cat's Claw: May increase the serum concentration of Saquinavir. Monitor therapy

Ceritinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Ceritinib. Management: Avoid use of ceritinib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, decrease ceritinib dose by one-third (to the nearest 150 mg) and monitor patients for ceritinib toxicities including QTc prolongation. Consider therapy modification

Ciclesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ciclesonide (Oral Inhalation). Monitor therapy

Cilostazol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cilostazol. Management: Consider reducing the cilostazol dose to 50 mg twice daily in adult patients who are also receiving strong inhibitors of CYP3A4. Consider therapy modification

Cinacalcet: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cinacalcet. Monitor therapy

Cisapride: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Cisapride. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Cisapride. Avoid combination

Citalopram: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Citalopram. Monitor therapy

Clarithromycin: Saquinavir may enhance the QTc-prolonging effect of Clarithromycin. Clarithromycin may increase the serum concentration of Saquinavir. Avoid combination

Clorazepate: Saquinavir may increase the serum concentration of Clorazepate. Monitor therapy

CloZAPine: Saquinavir may enhance the QTc-prolonging effect of CloZAPine. Avoid combination

Cobicistat: May increase the serum concentration of Saquinavir. However, the magnitude of this change is unclear, and dosing recommendations for this combination are not available. Avoid combination

Cobimetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cobimetinib. Avoid combination

Codeine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Codeine. Monitor therapy

Colchicine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Colchicine. Management: Colchicine is contraindicated in patients with impaired renal or hepatic function who are also receiving a strong CYP3A4 inhibitor. In those with normal renal and hepatic function, reduce colchicine dose as directed. See interaction monograph for details. Consider therapy modification

Conivaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Conivaptan. Avoid combination

Copanlisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Copanlisib. Management: If concomitant use of copanlisib and strong CYP3A4 inhibitors cannot be avoided, reduce the copanlisib dose to 45 mg. Monitor patients for increased copanlisib effects/toxicities. Consider therapy modification

Cortisone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cortisone. Monitor therapy

Crizotinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Crizotinib. Management: Avoid concomitant use of crizotinib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, decrease crizotinib dose to 250 mg daily. Monitor patients for crizotinib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

Cyclophosphamide: Protease Inhibitors may enhance the adverse/toxic effect of Cyclophosphamide. Specifically, the incidences of neutropenia, infection, and mucositis may be increased. Monitor therapy

CycloSPORINE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of CycloSPORINE (Systemic). Management: Monitor cyclosporine serum concentrations and clinical cyclosporine closely with concurrent use of any strong CYP3A4 inhibitor. Cyclosporine dose reductions and/or prolongation of the dosing interval will likely be required. Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP3A4 Substrates (High risk with Inhibitors): CYP3A4 Inhibitors (Strong) may decrease the metabolism of CYP3A4 Substrates (High risk with Inhibitors). Management: Consider avoiding this combination. Some combinations are specifically contraindicated by manufacturers; others may have recommended dose adjustments. If combined, monitor for increased substrate effects. Consider therapy modification

Dabrafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dabrafenib. Avoid combination

Daclatasvir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Daclatasvir. Management: Decrease the daclatasvir dose to 30 mg once daily if combined with a strong CYP3A4 inhibitor. No dose adjustment is needed when daclatasvir is used with darunavir/cobicistat. Consider therapy modification

Dapoxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dapoxetine. Avoid combination

Darifenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Darifenacin. Management: Limit the darifenacin dose to no more than 7.5 mg daily if combined with strong CYP3A4 inhibitors. Monitor patients for increased darifenacin toxicities (eg, dry mouth, constipation, headache, CNS effects) when these agents are combined. Consider therapy modification

Darunavir: Saquinavir may decrease the serum concentration of Darunavir. Avoid combination

Dasatinib: May enhance the QTc-prolonging effect of Saquinavir. Saquinavir may increase the serum concentration of Dasatinib. Avoid combination

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Deflazacort: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Deflazacort. Management: Administer one third of the recommended deflazacort dose when used together with a strong or moderate CYP3A4 inhibitor. Consider therapy modification

Delamanid: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Delamanid. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Delamanid. Management: If coadministration of delamanid with any strong CYP3A4 inhibitor is considered necessary, very frequent monitoring of ECGs is recommended throughout the full delamanid treatment period. Consider therapy modification

Delavirdine: May increase the serum concentration of Saquinavir. Consider therapy modification

DexAMETHasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DexAMETHasone (Ophthalmic). Monitor therapy

DiazePAM: Saquinavir may increase the serum concentration of DiazePAM. Monitor therapy

Disopyramide: Saquinavir may enhance the QTc-prolonging effect of Disopyramide. Saquinavir may increase the serum concentration of Disopyramide. Avoid combination

DOCEtaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of DOCEtaxel. Management: Avoid the concomitant use of docetaxel and strong CYP3A4 inhibitors when possible. If combined use is unavoidable, consider a 50% docetaxel dose reduction and monitor for increased docetaxel toxicities. Consider therapy modification

Domperidone: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Domperidone. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Domperidone. Avoid combination

Doxercalciferol: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Doxercalciferol. Monitor therapy

DOXOrubicin (Conventional): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to strong CYP3A4 inhibitors in patients treated with doxorubicin whenever possible. Prescribing information for at least one doxorubicin product recommends that these combinations be avoided. Consider therapy modification

Dronabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dronabinol. Monitor therapy

Dronedarone: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Dronedarone. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Dronedarone. Avoid combination

Drospirenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Drospirenone. Management: Drospirenone use is contraindicated specifically when the strong CYP3A4 inhibitors atazanavir and cobicistat are administered concurrently. Caution should be used when drospirenone is coadministered with other strong CYP3A4 inhibitors. Consider therapy modification

Dutasteride: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dutasteride. Monitor therapy

Duvelisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Duvelisib. Management: Reduce the dose of duvelisib to 15 mg twice a day when used together with a strong CYP3A4 inhibitor. Monitor closely for evidence of altered response to treatment. Consider therapy modification

Efavirenz: Saquinavir may enhance the adverse/toxic effect of Efavirenz. Efavirenz may decrease the serum concentration of Saquinavir. Management: When used together with efavirenz, saquinavir should not be used as the sole protease inhibitor. Appropriate doses of the combination of efavirenz with saquinavir/ritonavir have not been established. Consider therapy modification

Elagolix: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elagolix. Management: Use of the elagolix 200 mg twice daily dose with a strong CYP3A4 inhibitor for longer than 1 month is not recommended. Limit combined use of the elagolix 150 mg once daily dose with a strong CYP3A4 inhibitor to a maximum of 6 months. Consider therapy modification

Elagolix, Estradiol, and Norethindrone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elagolix, Estradiol, and Norethindrone. Avoid combination

Eletriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eletriptan. Avoid combination

Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Management: When combined with strong CYP3A4 inhibitors, administer two elexacaftor/tezacaftor/ivacaftor tablets (100 mg/50 mg/75 mg) in the morning, twice a week, approximately 3 to 4 days apart. No evening doses of ivacaftor (150 mg) alone should be administered. Consider therapy modification

Eliglustat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eliglustat. Management: Reduce eliglustat dose to 84 mg daily in CYP2D6 EMs when used with strong CYP3A4 inhibitors. Use of strong CYP3A4 inhibitors is contraindicated in CYP2D6 IMs, PMs, or in CYP2D6 EMs who are also taking strong or moderate CYP2D6 inhibitors. Consider therapy modification

Eluxadoline: Saquinavir may increase the serum concentration of Eluxadoline. Management: Decrease the eluxadoline dose to 75 mg twice daily if combined with saquinavir and monitor patients for increased eluxadoline effects/toxicities. Consider therapy modification

Encorafenib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Encorafenib. Management: Avoid use of encorafenib and strong CYP3A4 inhibitors when possible. If combined, decrease encorafenib dose from 450 mg to 150 mg; or from 300 mg, 225 mg, or 150 mg to 75 mg. Monitor closely for QT interval prolongation. Consider therapy modification

Enfortumab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Enfortumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Monitor therapy

Enfuvirtide: Protease Inhibitors may increase the serum concentration of Enfuvirtide. Enfuvirtide may increase the serum concentration of Protease Inhibitors. Monitor therapy

Entrectinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Entrectinib. Avoid combination

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification

Eplerenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eplerenone. Avoid combination

Erdafitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erdafitinib. Management: Avoid concomitant use of erdafitinib and strong CYP3A4 inhibitors when possible. If combined, monitor closely for erdafitinib adverse reactions and consider dose modifications accordingly. Consider therapy modification

Ergot Derivatives: Protease Inhibitors may increase the serum concentration of Ergot Derivatives. Avoid combination

Erlotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erlotinib. Management: Avoid use of this combination when possible. When the combination must be used, monitor the patient closely for the development of severe adverse reactions, and if such severe reactions occur, reduce the erlotinib dose (in 50 mg decrements). Consider therapy modification

Erythromycin (Systemic): May enhance the QTc-prolonging effect of Saquinavir. Erythromycin (Systemic) may increase the serum concentration of Saquinavir. Avoid combination

Estrogen Derivatives: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Estrogen Derivatives. Monitor therapy

Estrogen Derivatives (Contraceptive): Protease Inhibitors may decrease the serum concentration of Estrogen Derivatives (Contraceptive). Management: Use oral contraceptives containing at least 35mcg ethinyl estradiol with atazanavir/ritonavir, or no more than 30mcg in patients receiving atazanavir alone. Use of an alternative, non-hormonal contraceptive is recommended with other protease inhibitors. Consider therapy modification

Eszopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eszopiclone. Management: Limit the eszopiclone dose to 2 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased eszopiclone effects and toxicities (eg, somnolence, drowsiness, CNS depression). Consider therapy modification

Etizolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Etizolam. Management: Consider use of lower etizolam doses when using this combination; specific recommendations concerning dose adjustment are not available. Monitor clinical response to the combination closely. Consider therapy modification

Etravirine: Protease Inhibitors may decrease the serum concentration of Etravirine. This effect is anticipated with darunavir, saquinavir, and lopinavir (with low-dose ritonavir). Etravirine may increase the serum concentration of Protease Inhibitors. This effect is anticipated with nelfinavir. Management: Low-dose ritonavir boosting must be used when any protease inhibitor is used with etravirine. Avoid use of etravirine in combination with atazanavir, fosamprenavir, full-dose ritonavir (600 mg twice daily, in adults), or tipranavir. Monitor therapy

Everolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Everolimus. Management: Consider avoiding use of strong CYP3A4 inhibitors with everolimus. If combined, closely monitor for increased everolimus serum concentrations and toxicities. Everolimus dose reductions will likely be required. Consider therapy modification

Evogliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Evogliptin. Monitor therapy

Fedratinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fedratinib. Management: Consider alternatives when possible. If used together, decrease fedratinib dose to 200 mg/day. After the inhibitor is stopped, increase fedratinib to 300 mg/day for the first 2 weeks and then to 400 mg/day as tolerated. Consider therapy modification

FentaNYL: CYP3A4 Inhibitors (Strong) may increase the serum concentration of FentaNYL. Management: Consider fentanyl dose reductions when combined with a strong CYP3A4 inhibitor. Monitor for respiratory depression and sedation. Upon discontinuation of a CYP3A4 inhibitor, consider a fentanyl dose increase; monitor for signs and symptoms of withdrawal. Consider therapy modification

Fesoterodine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fesoterodine. Management: Limit fesoterodine doses to 4 mg daily in patients who are also receiving strong CYP3A4 inhibitors. Consider therapy modification

Fexinidazole [INT]: May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk). Avoid combination

Flibanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Flibanserin. Management: Use of flibanserin with strong CYP3A4 inhibitors is contraindicated. If starting flibanserin, start 2 weeks after the last dose of the CYP3A4 inhibitor. If starting a CYP3A4 inhibitor, start 2 days after the last dose of flibanserin. Avoid combination

Fluconazole: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Flurazepam: Saquinavir may increase the serum concentration of Flurazepam. Monitor therapy

Fluticasone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Nasal). Avoid combination

Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Oral Inhalation). Consider therapy modification

Fosaprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fosaprepitant. Avoid combination

Fostamatinib: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fostamatinib. Monitor therapy

Fusidic Acid (Systemic): Saquinavir may increase the serum concentration of Fusidic Acid (Systemic). Fusidic Acid (Systemic) may increase the serum concentration of Saquinavir. Avoid combination

Galantamine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Galantamine. Monitor therapy

Garlic: May decrease the serum concentration of Protease Inhibitors. Management: Concurrent use of garlic supplements with protease inhibitors is not recommended. If this combination is used, monitor closely for altered serum concentrations/effects of protease inhibitors, and particularly for signs/symptoms of therapeutic failure. Consider therapy modification

Gefitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Gefitinib. Monitor therapy

Gilteritinib: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Gilteritinib. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Gilteritinib. Management: Consider alternatives to the use of gilteritinib with strong CYP3A4 inhibitors that prolong the QTc interval whenever possible Consider therapy modification

Glasdegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Glasdegib. Management: Consider alternatives to this combination when possible. If the combination must be used, monitor closely for evidence of QT interval prolongation and other adverse reactions to glasdegib. Consider therapy modification

Grazoprevir: Saquinavir may increase the serum concentration of Grazoprevir. Avoid combination

GuanFACINE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of GuanFACINE. Management: Reduce the extended-release guanfacine dose 50% when combined with a strong CYP3A4 inhibitor. Monitor for increased guanfacine toxicities when these agents are combined. Consider therapy modification

Halofantrine: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Halofantrine. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Halofantrine. Avoid combination

Haloperidol: Saquinavir may enhance the QTc-prolonging effect of Haloperidol. Avoid combination

Histamine H2 Receptor Antagonists: May increase the serum concentration of Saquinavir. Monitor therapy

HYDROcodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of HYDROcodone. Monitor therapy

Hydrocortisone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Hydrocortisone (Systemic). Monitor therapy

Ibrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ibrutinib. Management: Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for 7 days or less), interrupt ibrutinib therapy until the strong CYP3A4 inhibitor is discontinued. Avoid combination

Idelalisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Idelalisib. Monitor therapy

Ifosfamide: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. Monitor therapy

Iloperidone: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolites P88 and P95 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Iloperidone. Management: Reduce iloperidone dose by half when administered with a strong CYP3A4 inhibitor. Consider therapy modification

Imatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imatinib. Monitor therapy

Imidafenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imidafenacin. Monitor therapy

Irinotecan Products: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Irinotecan Products. Specifically, serum concentrations of SN-38 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Irinotecan Products. Avoid combination

Isavuconazonium Sulfate: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Isavuconazonium Sulfate. Specifically, CYP3A4 Inhibitors (Strong) may increase isavuconazole serum concentrations. Management: Combined use is considered contraindicated per US labeling. Lopinavir/ritonavir (and possibly other uses of ritonavir doses less than 400 mg every 12 hours) is treated as a possible exception to this contraindication despite strongly inhibiting CYP3A4. Avoid combination

Istradefylline: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Istradefylline. Management: Limit the maximum istradefylline dose to 20 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased istradefylline effects/toxicities. Consider therapy modification

Itraconazole: May increase the serum concentration of Saquinavir. Saquinavir may increase the serum concentration of Itraconazole. Management: Limit the adult maximum itraconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir. Consider therapy modification

Ivabradine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivabradine. Avoid combination

Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivacaftor. Management: Ivacaftor dose reductions are required; consult full drug interaction monograph content for age- and weight-specific recommendations. Consider therapy modification

Ivosidenib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Ivosidenib. Management: Avoid using strong CYP3A4 inhibitors together with ivosidenib if possible. If the combination must be used, reduce the ivosidenib dose to 250 mg once daily. Consider therapy modification

Ixabepilone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ixabepilone. Management: Avoid use of ixabepilone and strong CYP3A4 inhibitors when possible. If combined, reduce the ixabepilone dose to 20 mg/m2. The previous ixabepilone dose can be resumed 1 week after discontinuation of the strong CYP3A4 inhibitor. Consider therapy modification

Ketoconazole (Systemic): Saquinavir may increase the serum concentration of Ketoconazole (Systemic). Ketoconazole (Systemic) may increase the serum concentration of Saquinavir. Management: Limit the adult maximum ketoconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir. Consider therapy modification

Lapatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lapatinib. Management: Avoid use of lapatinib and strong CYP3A4 inhibitors when possible. If combined, reduce lapatinib dose to 500 mg daily. The previous lapatinib dose can be resumed 1 week after discontinuation of the strong CYP3A4 inhibitor. Consider therapy modification

Larotrectinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Larotrectinib. Management: Avoid use of strong CYP3A4 inhibitors with larotrectinib. If this combination cannot be avoided, reduce the larotrectinib dose by 50%. Increase to previous dose after stopping the inhibitor after a period of 3 to 5 times the inhibitor's half-life. Consider therapy modification

Lefamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin tablets and strong inhibitors of CYP3A4. Avoid combination

Lemborexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lemborexant. Avoid combination

Lercanidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lercanidipine. Avoid combination

Levamlodipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levamlodipine. Monitor therapy

Levobupivacaine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levobupivacaine. Monitor therapy

Levomethadone: Saquinavir may decrease the serum concentration of Levomethadone. Monitor therapy

Levomilnacipran: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levomilnacipran. Management: Do not exceed a maximum adult levomilnacipran dose of 80 mg/day in patients also receiving strong CYP3A4 inhibitors. Consider therapy modification

Lidocaine (Systemic): Saquinavir may enhance the arrhythmogenic effect of Lidocaine (Systemic). Saquinavir may increase the serum concentration of Lidocaine (Systemic). Avoid combination

Lomitapide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lomitapide. Avoid combination

Lopinavir: May enhance the QTc-prolonging effect of Saquinavir. Monitor therapy

Lorlatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lorlatinib. Management: Avoid use of lorlatinib with strong CYP3A4 inhibitors. If the combination cannot be avoided, reduce the lorlatinib dose from 100 mg once daily to 75 mg once daily, or from 75 mg once daily to 50 mg once daily. Consider therapy modification

Lovastatin: Protease Inhibitors may increase the serum concentration of Lovastatin. Avoid combination

Lovastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lovastatin. Avoid combination

Lumacaftor and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumacaftor and Ivacaftor. Management: When initiating or resuming lumacaftor/ivacaftor after a therapy interruption of 7 days or more, reduce the lumacaftor/ivacaftor dose to 1 tablet daily or 1 packet of oral granules every other day for the first week, and then resume the standard dose. Consider therapy modification

Lumateperone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumateperone. Avoid combination

Lumefantrine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumefantrine. Monitor therapy

Lurasidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lurasidone. Avoid combination

Lurbinectedin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lurbinectedin. Avoid combination

Macitentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Macitentan. Avoid combination

Manidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Manidipine. Management: Consider avoiding concomitant use of manidipine and strong CYP3A4 inhibitors. If combined, monitor closely for increased manidipine effects and toxicities. Manidipine dose reductions may be required. Consider therapy modification

Maraviroc: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Maraviroc. Management: Reduce maraviroc to 150mg twice/day in adult and pediatrics weighing 40kg or more. See full interaction monograph for dose adjustments in pediatrics weighing 10 to less than 40kg. Do not use if CrCl less than 30mL/min or in those weighing less than 10 kg. Consider therapy modification

Meperidine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Meperidine. Monitor therapy

Methadone: Saquinavir may enhance the QTc-prolonging effect of Methadone. Saquinavir may decrease the serum concentration of Methadone. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation, ventricular arrhythmias, and opioid withdrawal symptoms. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Midazolam: Protease Inhibitors may increase the serum concentration of Midazolam. Management: Oral midazolam contraindicated with all protease inhibitors. IV midazolam contraindicated with fosamprenavir and nelfinavir; other protease inhibitors recommend caution, close monitoring, and consideration of lower IV midazolam doses with concurrent use. Avoid combination

Midostaurin: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Midostaurin. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Midostaurin. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

MiFEPRIStone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MiFEPRIStone. Management: For treatment of hyperglycemia in Cushing's syndrome, start mifepristone at 300 mg/day, may titrate to a maximum of 900 mg/day. If starting a strong CYP3A4 inhibitor and taking >300 mg/day mifepristone, decrease the mifepristone dose by 300 mg/day. Consider therapy modification

Mirodenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirodenafil. Management: Consider using a lower dose of mirodenafil when used with strong CYP3A4 inhibitors. Monitor for increased mirodenafil effects/toxicities with the use of this combination. Consider therapy modification

Mirtazapine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirtazapine. Monitor therapy

Mitotane: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification

Mometasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mometasone (Oral Inhalation). Monitor therapy

Naldemedine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naldemedine. Monitor therapy

Nalfurafine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nalfurafine. Monitor therapy

Naloxegol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naloxegol. Avoid combination

Nefazodone: Protease Inhibitors may increase the serum concentration of Nefazodone. Management: Consider alternatives to, or reduced doses of, nefazodone in patients treated with HIV protease inhibitors. Monitor patients receiving these combinations closely for toxic effects of nefazodone. Consider therapy modification

Neratinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Neratinib. Avoid combination

Nevirapine: May decrease the serum concentration of Saquinavir. Avoid combination

Nilotinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Nilotinib. Management: Avoid concomitant use of nilotinib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, nilotinib dose reductions are required. Monitor patients for nilotinib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

NiMODipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of NiMODipine. Avoid combination

Nisoldipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nisoldipine. Avoid combination

Olaparib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Olaparib. Management: Avoid use of strong CYP3A4 inhibitors with olaparib, if possible. If such concurrent use cannot be avoided, the dose of olaparib tablets should be reduced to 100 mg twice daily and the dose of olaparib capsules should be reduced to 150 mg twice daily. Consider therapy modification

Oliceridine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Oliceridine. Monitor therapy

Ondansetron: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Ondansetron. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Orlistat: May decrease the serum concentration of Antiretroviral Agents. Monitor therapy

Osilodrostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Osilodrostat. Management: Reduce osilodrostat dose by 50% during coadministration with a strong CYP3A4 inhibitor. Consider therapy modification

Osimertinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Ospemifene: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ospemifene. Monitor therapy

Oxybutynin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Oxybutynin. Monitor therapy

Palbociclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Palbociclib. Management: Avoid concurrent use of strong CYP3A4 inhibitors with palbociclib when possible. If the use of a strong CYP3A4 inhibitor cannot be avoided, decrease the palbociclib dose to 75 mg/day. Consider therapy modification

Panobinostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Panobinostat. Management: Reduce the panobinostat dose to 10 mg when it must be used with a strong CYP3A4 inhibitor. Monitor patient response to therapy closely for evidence of more severe adverse effects related to panobinostat therapy. Consider therapy modification

Parecoxib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Parecoxib. Specifically, serum concentrations of the active moiety valdecoxib may be increased. Monitor therapy

Paricalcitol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Paricalcitol. Monitor therapy

PAZOPanib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PAZOPanib. Management: Avoid concurrent use of pazopanib with strong inhibitors of CYP3A4 whenever possible. If it is not possible to avoid such a combination, reduce pazopanib dose to 400 mg. Further dose reductions may also be required if adverse reactions occur. Consider therapy modification

Pemigatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pemigatinib. Management: If combined use cannot be avoided, reduce the pemigatinib dose from 13.5 mg daily to 9 mg daily, or from 9 mg daily to 4.5 mg daily. Resume prior pemigatinib dose after stopping the strong inhibitor once 3 half-lives of the inhibitor has passed. Consider therapy modification

Pentamidine (Systemic): May enhance the QTc-prolonging effect of Saquinavir. Avoid combination

Pexidartinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pexidartinib. Management: Avoid use of pexidartinib with strong CYP3A4 inhibitors if possible. If combined use cannot be avoided, pexidartinib dose should be reduced. Decrease 800 mg or 600 mg daily doses to 200 mg twice daily. Decrease doses of 400 mg per day to 200 mg once daily Consider therapy modification

P-glycoprotein/ABCB1 Inhibitors: May increase the serum concentration of Saquinavir. Monitor therapy

Pimavanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimavanserin. Management: Decrease the pimavanserin dose to 10 mg daily when combined with strong CYP3A4 inhibitors. Consider therapy modification

Pimecrolimus: CYP3A4 Inhibitors (Strong) may decrease the metabolism of Pimecrolimus. Monitor therapy

Pimozide: Protease Inhibitors may increase the serum concentration of Pimozide. Avoid combination

Pimozide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimozide. Avoid combination

Pimozide: May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk). Avoid combination

Piperaquine: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Piperaquine. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Piperaquine. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Polatuzumab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Polatuzumab Vedotin. Exposure to unconjugated MMAE, the cytotoxic small molecule component of polatuzumab vedotin, may be increased. Monitor therapy

PONATinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PONATinib. Management: Reduce the adult starting dose of ponatinib to 30 mg daily during treatment with any strong CYP3A4 inhibitor. Consider therapy modification

Pralsetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pralsetinib. Avoid combination

Pranlukast: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pranlukast. Monitor therapy

Pravastatin: Saquinavir may decrease the serum concentration of Pravastatin. This effect has only been demonstrated with saquinavir/ritonavir. The individual contributions of saquinavir and ritonavir are unknown. Monitor therapy

Praziquantel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Praziquantel. Monitor therapy

PrednisoLONE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of PrednisoLONE (Systemic). Monitor therapy

PredniSONE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PredniSONE. Monitor therapy

Progestins (Contraceptive): Saquinavir may decrease the serum concentration of Progestins (Contraceptive). Management: Use an alternative or additional method of contraception due to possibly decreased contraceptive effectiveness. Injected depot medroxyprogesterone acetate does not appear to participate in this interaction. Consider therapy modification

Protease Inhibitors: May increase the serum concentration of other Protease Inhibitors. Management: Atazanavir--indinavir combination contraindicated. Tipranavir/ritonavir or atazanavir/ritonavir not recommended with other protease inhibitors (PI). Darunavir/cobicistat not recommended with PI that require boosting.Other combos may require dose changes. Consider therapy modification

Proton Pump Inhibitors: May increase the serum concentration of Saquinavir. Monitor therapy

QT-prolonging Antidepressants (Moderate Risk): QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Antidepressants (Moderate Risk). Monitor therapy

QT-prolonging Antipsychotics (Moderate Risk): May enhance the QTc-prolonging effect of Saquinavir. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Class IA Antiarrhythmics (Highest Risk): May enhance the QTc-prolonging effect of Saquinavir. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

QT-prolonging Class IC Antiarrhythmics (Moderate Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Class III Antiarrhythmics (Highest Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Class III Antiarrhythmics (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

QT-prolonging Kinase Inhibitors (Highest Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Kinase Inhibitors (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

QT-prolonging Miscellaneous Agents (Highest Risk): QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Miscellaneous Agents (Highest Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Miscellaneous Agents (Highest Risk). Avoid combination

QT-prolonging Miscellaneous Agents (Moderate Risk): QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Miscellaneous Agents (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Miscellaneous Agents (Moderate Risk). Avoid combination

QT-prolonging Quinolone Antibiotics (Moderate Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QUEtiapine: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QUEtiapine. Management: Reduce the quetiapine dose to one-sixth of the regular dose when initiating these strong CYP3A4 inhibitors. In patients already receiving these strong CYP3A4 inhibitors, initiate quetiapine at the lowest dose and titrate cautiously as needed. Consider therapy modification

QuiNIDine: Saquinavir may enhance the QTc-prolonging effect of QuiNIDine. Avoid combination

Quinidine (Non-Therapeutic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Quinidine (Non-Therapeutic). Monitor therapy

Radotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Radotinib. Avoid combination

Ramelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ramelteon. Monitor therapy

Ranolazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ranolazine. Avoid combination

Red Yeast Rice: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Red Yeast Rice. Specifically, concentrations of lovastatin and related compounds found in Red Yeast Rice may be increased. Avoid combination

Regorafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Regorafenib. Avoid combination

Repaglinide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Repaglinide. Management: The addition of a CYP2C8 inhibitor to this drug combination may substantially increase the magnitude of increase in repaglinide exposure. Monitor therapy

Retapamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Retapamulin. Management: Avoid this combination in patients less than 2 years old. No action is required in other populations. Monitor therapy

Ribociclib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Ribociclib. Management: Avoid concomitant use of ribociclib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, decrease the ribociclib dose to 400 mg daily. Monitor for ribociclib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

Rifabutin: Saquinavir may increase serum concentrations of the active metabolite(s) of Rifabutin. Rifabutin may decrease the serum concentration of Saquinavir. Saquinavir may increase the serum concentration of Rifabutin. Management: Reduce rifabutin doses. Saquinavir US labeling recommends a decrease of at least 75%, to 150 mg every other day or 3 times per week for adults. Clinical guidelines recommend 150 mg daily or 300 mg 3 times per week when used with saquinavir/ritonavir. Consider therapy modification

RifAMPin: May enhance the adverse/toxic effect of Saquinavir. Specifically, the risk of hepatocellular toxicity may be increased. RifAMPin may decrease the serum concentration of Saquinavir. Avoid combination

Rilpivirine: Saquinavir may enhance the arrhythmogenic effect of Rilpivirine. Saquinavir may increase the serum concentration of Rilpivirine. Avoid combination

Rimegepant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rimegepant. Avoid combination

Riociguat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Riociguat. Monitor therapy

Ripretinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ripretinib. Monitor therapy

RomiDEPsin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of RomiDEPsin. Monitor therapy

Rosuvastatin: Protease Inhibitors may increase the serum concentration of Rosuvastatin. Management: Limit rosuvastatin to 10 mg daily in patients receiving atazanavir/ritonavir or lopinavir/ritonavir. Patients receiving fosamprenavir/ritonavir or tipranavir/ritonavir do not require dose adjustments if rosuvastatin is used concomitantly. Consider therapy modification

Rupatadine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rupatadine. Avoid combination

Ruxolitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ruxolitinib. Management: This combination should be avoided under some circumstances; dose adjustments may be required in some circumstances and depend on the indication for ruxolitinib. See monograph for details. Consider therapy modification

Salmeterol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Salmeterol. Avoid combination

Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

SAXagliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SAXagliptin. Management: Limit the saxagliptin dose to 2.5 mg daily when combined with strong CYP3A4 inhibitors. When using the saxagliptin combination products saxagliptin/dapagliflozin or saxagliptin/dapagliflozin/metformin, avoid use with strong CYP3A4 inhibitors. Consider therapy modification

Selpercatinib: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Selpercatinib. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Selpercatinib. Management: Avoid combination if possible. If use is necessary, reduce selpercatinib dose as follows: from 120mg twice/day to 40mg twice/day, or from 160mg twice/day to 80mg twice/day. Monitor QT interval more closely for QTc interval prolongation and arrhythmias. Consider therapy modification

Selumetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Selumetinib. Management: Avoid concomitant use when possible. If combined, selumetinib dose reductions are recommended and vary based on body surface area and selumetinib dose. For details, see the full drug interaction monograph or selumetinib prescribing information. Consider therapy modification

Sibutramine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Sibutramine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sibutramine. Monitor therapy

Sildenafil: Saquinavir may increase the serum concentration of Sildenafil. Management: Used for pulmonary arterial hypertension: no dose adjustment recommended per US label; Canadian label recommends decrease to 20 mg twice/day. Used for erectile dysfunction: consider a lower starting dose of 25 mg with concurrent saquinavir. Consider therapy modification

Silodosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Silodosin. Avoid combination

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Simeprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simeprevir. Avoid combination

Simeprevir: Protease Inhibitors may increase the serum concentration of Simeprevir. Simeprevir may increase the serum concentration of Protease Inhibitors. Avoid combination

Simvastatin: Protease Inhibitors may increase the serum concentration of Simvastatin. Avoid combination

Simvastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simvastatin. Avoid combination

Sirolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sirolimus. Management: Avoid concurrent use of sirolimus with strong CYP3A4 inhibitors when possible and alternative agents with lesser interaction potential with sirolimus should be considered. Concomitant use of sirolimus and voriconazole or posaconazole is contraindicated. Consider therapy modification

Solifenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Solifenacin. Management: Limit adult solifenacin doses to 5 mg daily and limit doses in pediatric patients to the recommended weight-based starting dose (and do not increase the dose) when combined with strong CYP3A4 inhibitors. Consider therapy modification

Sonidegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sonidegib. Avoid combination

SORAfenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SORAfenib. Monitor therapy

St John's Wort: May increase the metabolism of Protease Inhibitors. Avoid combination

SUFentanil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SUFentanil. Management: If a strong CYP3A4 inhibitor is initiated in a patient on sufentanil, consider a sufentanil dose reduction and monitor for increased sufentanil effects and toxicities (eg, respiratory depression). Consider therapy modification

SUNItinib: Saquinavir may increase the serum concentration of SUNItinib. Avoid combination

Suvorexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Suvorexant. Avoid combination

Tacrolimus (Systemic): Saquinavir may increase the serum concentration of Tacrolimus (Systemic). Avoid combination

Tacrolimus (Topical): Protease Inhibitors may decrease the metabolism of Tacrolimus (Topical). Monitor therapy

Tadalafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tadalafil. Management: Avoid this combination in patients taking tadalafil for pulmonary arterial hypertension. In patients taking tadalafil for ED or BPH, max tadalafil dose is 2.5 mg if taking daily or 10 mg no more frequently than every 72 hours if used as needed. Consider therapy modification

Tamsulosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tamsulosin. Avoid combination

Tasimelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tasimelteon. Monitor therapy

Tazemetostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tazemetostat. Avoid combination

Telithromycin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Telithromycin. Monitor therapy

Temsirolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Temsirolimus. Management: Avoid concomitant use of temsirolimus and strong CYP3A4 inhibitors. If coadministration is unavoidable, decrease temsirolimus dose to 12.5 mg per week. Resume previous temsirolimus dose 1 week after discontinuation of the strong CYP3A4 inhibitor. Consider therapy modification

Terfenadine: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Terfenadine. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Terfenadine. Avoid combination

Tetrahydrocannabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol and Cannabidiol. Monitor therapy

Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tezacaftor and Ivacaftor. Management: If combined with strong CYP3A4 inhibitors, tezacaftor/ivacaftor should be administered in the morning, twice a week, approximately 3 to 4 days apart. Tezacaftor/ivacaftor dose depends on age and weight; see full Lexi-Interact monograph for details. Consider therapy modification

Thioridazine: Saquinavir may enhance the QTc-prolonging effect of Thioridazine. Avoid combination

Thiotepa: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Thiotepa. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Thiotepa. Management: Thiotepa prescribing information recommends avoiding concomitant use of thiotepa and strong CYP3A4 inhibitors. If concomitant use is unavoidable, monitor for adverse effects and decreased efficacy. Consider therapy modification

Ticagrelor: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ticagrelor. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ticagrelor. Avoid combination

Tipranavir: May decrease the serum concentration of Protease Inhibitors. Avoid combination

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Tofacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tofacitinib. Management: Tofacitinib dose reductions are recommended when combined with strong CYP3A4 inhibitors. Recommended dose adjustments vary by tofacitinib formulation and therapeutic indication. See full Lexi Interact monograph for details. Consider therapy modification

Tolterodine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolterodine. Management: The maximum recommended dose of tolterodine is 2 mg per day (1 mg twice daily for immediate-release tablets or 2 mg daily for extended-release capsules) when used together with a strong CYP3A4 inhibitor. Consider therapy modification

Tolvaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolvaptan. Avoid combination

Toremifene: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Toremifene. Management: Avoid concomitant use of toremifene and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, monitor patients for toremifene toxicities including QTc prolongation and TdP. Consider therapy modification

Trabectedin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Trabectedin. Avoid combination

TraMADol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of TraMADol. Monitor therapy

TraZODone: Saquinavir may enhance the QTc-prolonging effect of TraZODone. Saquinavir may increase the serum concentration of TraZODone. Avoid combination

Triamcinolone (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triamcinolone (Systemic). Monitor therapy

Triazolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triazolam. Avoid combination

Ubrogepant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ubrogepant. Avoid combination

Udenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Udenafil. Avoid combination

Ulipristal: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ulipristal. Management: This is specific for when ulipristal is being used for signs/symptoms of uterine fibroids (Canadian indication). When ulipristal is used as an emergency contraceptive, patients receiving this combo should be monitored for ulipristal toxicity. Avoid combination

Upadacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Upadacitinib. Monitor therapy

Valbenazine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Valbenazine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Valbenazine. Management: Reduce the valbenazine dose to 40 mg daily when combined with strong CYP3A4 inhibitors. Consider therapy modification

Valproate Products: Protease Inhibitors may decrease the serum concentration of Valproate Products. Monitor therapy

Vardenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vardenafil. Management: Limit Levitra (vardenafil) dose to a single 2.5 mg dose within a 24-hour period if combined with strong CYP3A4 inhibitors. Avoid concomitant use of Staxyn (vardenafil) and strong CYP3A4 inhibitors. Combined use is contraindicated outside of the US. Consider therapy modification

Vemurafenib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Vemurafenib. Management: Avoid concomitant use of vemurafenib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined monitor patients for vemurafenib toxicities including QTc prolongation and TdP, and consider a vemurafenib dose reduction. Consider therapy modification

Venetoclax: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Venetoclax. Management: Coadministration is contraindicated during venetoclax initiation and ramp-up in CLL/SLL patients. Reduced venetoclax doses are required during ramp-up for patients with AML, and all maintenance therapy. See full Lexi Interact monograph for details. Consider therapy modification

Verapamil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Verapamil. Management: Consider alternatives to this combination when possible. If combined, monitor for increased verapamil effects and toxicities (eg, hypotension, bradycardia). Consider therapy modification

Vilanterol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilanterol. Monitor therapy

Vilazodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilazodone. Management: Limit the maximum vilazodone dose to 20 mg daily in patients receiving strong CYP3A4 inhibitors. The original vilazodone dose can be resumed following discontinuation of the strong CYP3A4 inhibitor. Consider therapy modification

VinBLAStine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinBLAStine. Monitor therapy

VinCRIStine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinCRIStine. Management: Seek alternatives to this combination when possible. If combined, monitor closely for vincristine toxicities (eg, neurotoxicity, gastrointestinal toxicity, myelosuppression). Consider therapy modification

VinCRIStine (Liposomal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinCRIStine (Liposomal). Avoid combination

Vindesine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vindesine. Monitor therapy

Vinflunine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinflunine. Avoid combination

Vinorelbine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinorelbine. Monitor therapy

Vorapaxar: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vorapaxar. Avoid combination

Voriconazole: Saquinavir may enhance the QTc-prolonging effect of Voriconazole. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Voxelotor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Voxelotor. Management: Avoid concomitant use of voxelotor and strong CYP3A4 inhibitors. If concomitant use is unavoidable, reduce the voxelotor dose to 1,000 mg once daily. Consider therapy modification

Warfarin: Saquinavir may increase the serum concentration of Warfarin. Monitor therapy

Zanubrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zanubrutinib. Management: Decrease the zanubrutinib dose to 80 mg once daily during coadministration with a strong CYP3A4 inhibitor. Further dose adjustments may be required for zanubrutinib toxicities, refer to prescribing information for details. Consider therapy modification

Zidovudine: Protease Inhibitors may decrease the serum concentration of Zidovudine. Monitor therapy

Zolpidem: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zolpidem. Monitor therapy

Zopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zopiclone. Management: If coadministered with strong CYP3A4 inhibitors, initiate zopiclone at 3.75 mg in adults, with a maximum dose of 5 mg. Monitor for zopiclone toxicity (eg, drowsiness, confusion, lethargy, ataxia, respiratory depression). Consider therapy modification

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

Incidence data for saquinavir soft gel capsule formulation (no longer available) in combination with ritonavir:

10%: Gastrointestinal: Nausea (11%)

1% to 10%:

Cardiovascular: Chest pain

Central nervous system: Fatigue (6%), anxiety, depression, headache, insomnia, pain, paresthesia

Dermatologic: Pruritus (3%), skin rash (3%), eczema (2%), cheilosis (≤2%), xeroderma (≤2%), warts

Endocrine & metabolic: Lipodystrophy (5%), hyperglycemia (3%), change in libido, hypoglycemia, hyperkalemia

Gastrointestinal: Diarrhea (8%), vomiting (7%), abdominal pain (6%), constipation (2%), abdominal distress, decreased appetite, dysgeusia, dyspepsia, flatulence, increased serum amylase, oral mucosa ulcer

Hepatic: Increased serum ALT, increased serum AST, increased serum bilirubin

Infection: Influenza (3%)

Neuromuscular & skeletal: Back pain (2%), increased creatine phosphokinase, weakness

Respiratory: Pneumonia (5%), bronchitis (3%), sinusitis (3%)

Miscellaneous: Fever (3%)

Frequency not defined; reported for hard or soft gel capsule with/without ritonavir:

Cardiovascular: Heart valve disease (including murmur), hypertension, hypotension, peripheral vasoconstriction, prolongation P-R interval on ECG, prolonged QT interval on ECG, syncope, thrombophlebitis

Central nervous system: Agitation, amnesia, ataxia, colic, confusion, drowsiness, hallucination, hyperreflexia, hyporeflexia, neuropathy, poliomyelitis, progressive multifocal leukoencephalopathy, psychosis, seizure, speech disturbance

Dermatologic: Alopecia, bullous dermatitis, dermal ulcer, dermatitis, erythema, maculopapular rash, skin photosensitivity, Stevens-Johnson syndrome, urticaria

Endocrine & metabolic: Dehydration, diabetes mellitus, electrolyte disturbance, increased gamma-glutamyl transferase, increased lactate dehydrogenase, increased thyroid stimulating hormone level

Gastrointestinal: Bloody stools, dysphagia, esophagitis, gastritis, intestinal obstruction, pancreatitis, stomatitis

Genitourinary: Benign prostatic hypertrophy, hematuria, impotence, urinary tract infection

Hematologic & oncologic: Acute myelocytic leukemia, anemia (including hemolytic), leukopenia, neutropenia, pancytopenia, rectal hemorrhage, splenomegaly, thrombocytopenia

Hepatic: Ascites, hepatic disease (exacerbation), hepatitis, hepatomegaly, hepatosplenomegaly, increased serum alkaline phosphatase, jaundice

Immunologic: Immune reconstitution syndrome

Infection: Infection (bacterial, fungal, viral)

Neuromuscular & skeletal: Arthritis

Ophthalmic: Blepharitis, visual disturbance

Otic: Auditory impairment, otitis, tinnitus

Renal: Nephrolithiasis

Respiratory: Cyanosis, dyspnea, hemoptysis, pharyngitis, upper respiratory tract infection

<1%, postmarketing, and/or case reports: Atrioventricular block (second or third degree), autoimmune disease, torsades de pointes

Warnings/Precautions

Concerns related to adverse effects:

• Altered cardiac conduction: Saquinavir/ritonavir prolongs the QT interval, potentially leading to torsade de pointes, and prolongs the PR interval, potentially leading to heart block. Second- or third-degree AV block has been reported (rare). An ECG should be performed for all patients prior to starting saquinavir/ritonavir therapy; do not initiate therapy in patients with a baseline QT interval ≥450 msec or diagnosed with long QT syndrome. If baseline QT interval <450 msec, may initiate saquinavir/ritonavir, but a subsequent ECG is recommended after ~10 days of therapy. For patients already receiving saquinavir/ritonavir that require concomitant therapy with another medication with the potential to prolong the QT interval, may initiate the concomitant therapy if baseline QT interval <450 msec, but a subsequent ECG is recommended after 3 to 4 days of therapy. If subsequent QT interval is prolonged over baseline by >20 msec, therapy should be discontinued. Patients who may be at increased risk for QT- or PR-interval prolongation include those with heart failure, bradyarrhythmias, hepatic impairment, electrolyte abnormalities, ischemic heart disease, cardiomyopathy, structural heart disease, or those with pre-existing cardiac conduction abnormalities; ECG monitoring is recommended for these patients. Discontinue therapy if significant arrhythmia or PR prolongation occur.

• Fat redistribution: May cause redistribution of fat (eg, buffalo hump, peripheral wasting with increased abdominal girth, cushingoid appearance).

• Immune reconstitution syndrome: Patients may develop immune reconstitution syndrome resulting in the occurrence of an inflammatory response to an indolent or residual opportunistic infection during initial HIV treatment or activation of autoimmune disorders (eg, Graves’ disease, polymyositis, Guillain-Barré syndrome) later in therapy; further evaluation and treatment may be required.

• Increased cholesterol: Increases in total cholesterol and triglycerides have been reported; screening should be done prior to therapy and periodically throughout treatment.

• Photosensitivity reactions: May cause photosensitivity reactions (eg, exposure to sunlight may cause severe sunburn, skin rash, redness, or itching); advise patient to avoid exposure to sunlight and artificial light sources (eg, sunlamps, tanning bed/booth) and to wear protective clothing, wide-brimmed hats, sunglasses, and lip sunscreen (SPF ≥15). Sunscreen should be used (broad-spectrum sunscreen or physical sunscreen [preferred] or sunblock with SPF ≥15) (HHS [pediatric] 2016).

Disease-related concerns:

• Diabetes: Changes in glucose tolerance, hyperglycemia, exacerbation of diabetes, DKA, and new-onset diabetes mellitus have been reported in patients receiving protease inhibitors.

• Electrolyte imbalances: Correct electrolyte abnormalities prior to treatment and monitor potassium and magnesium levels during therapy.

• Hemophilia A or B: Use with caution in patients with hemophilia A or B; increased bleeding during protease inhibitor therapy has been reported.

• Hepatic impairment: Use with caution in patients with underlying mild-to-moderate hepatic disease, including hepatitis B or C, cirrhosis, or chronic alcoholism; may cause hepatitis, portal hypertension, jaundice, and/or exacerbate preexisting hepatic dysfunction; contraindicated in severe hepatic impairment. Discontinue saquinavir/ritonavir if severe hepatotoxicity occurs.

• Lactose intolerance: Contains lactose; use not recommended in patients with rare hereditary disorders of lactose intolerance (eg, congenital lactase deficiency, glucose-galactose malabsorption).

Other warnings/precautions:

• Appropriate use: Must be used in combination with ritonavir. Not recommended for use in combination with cobicistat; dosing recommendations for this combination have not been established.

• Cross-resistance to other HIV drugs: Continued administration after loss of viral suppression efficacy may increase the likelihood of cross-resistance to other protease inhibitors. Promptly discontinue therapy if viral suppression response is lost.

Monitoring Parameters

Monitor ECG (prior to therapy and after 3 to 4 days of therapy [patients already receiving saquinavir/ritonavir and initiating concomitant QT prolonging therapy] or after ~10 days of therapy [patients initiating saquinavir/ritonavir]); serum potassium and magnesium levels, triglycerides and cholesterol (prior to initiation and periodically during therapy); viral load, CD4 count; glucose

Reproductive Considerations

Based on the Health and Humans Services (HHS) perinatal HIV guidelines, saquinavir is not one of the recommended antiretroviral agents for use in females living with HIV who are trying to conceive.

Females living with HIV not planning a pregnancy may use any available type of contraception, considering possible drug interactions and contraindications of the specific method. Consult the drug interactions database for more detailed information specific to use of saquinavir and specific contraceptives.

For males and females living with HIV and planning a pregnancy, maximum viral suppression below the limits of detection with antiretroviral therapy (ART), modification of therapy (if needed), optimization of the woman’s health, and a discussion of the potential risks and benefits of ART therapy during pregnancy is recommended prior to conception (HHS [perinatal] 2019).

Pregnancy Considerations

Saquinavir crosses the human placenta.

Outcome information specific to saquinavir use in pregnancy is no longer being reviewed and updated in the Health and Humans Services (HHS) perinatal guidelines. Maternal antiretroviral therapy (ART) may be associated with adverse pregnancy outcomes including preterm delivery, stillbirth, low birth weight, and small for gestational age infants. Actual risks may be influenced by maternal factors, such as disease severity, gestational age at initiation of therapy, and specific ART regimen; therefore, close fetal monitoring is recommended. Because there is clear benefit to appropriate treatment, maternal ART should not be withheld due to concerns for adverse neonatal outcomes. Long-term follow-up is recommended for all infants exposed to antiretroviral medications; children without HIV but who were exposed to ART in utero and develop significant organ system abnormalities of unknown etiology (particularly of the CNS or heart) should be evaluated for potential mitochondrial dysfunction. Hyperglycemia, new onset of diabetes mellitus, or diabetic ketoacidosis have been reported with protease inhibitors (PI); it is not clear if pregnancy increases this risk. Consider performing the standard glucose screening test earlier in pregnancy in women who initiated PI therapy prior to conception.

Based on the HHS perinatal HIV guidelines, saquinavir is not one of the recommended antiretroviral agents for use during pregnancy.

In general, ART is recommended for all pregnant females living with HIV to keep the viral load below the limit of detection and reduce the risk of perinatal transmission. Therapy should be individualized following a discussion of the potential risks and benefits of treatment during pregnancy. Monitoring of pregnant females is more frequent than in nonpregnant adults. ART should be continued postpartum for all females living with HIV and can be modified after delivery.

Health care providers are encouraged to enroll pregnant females exposed to antiretroviral medications as early in pregnancy as possible in the Antiretroviral Pregnancy Registry (1-800-258-4263 or http://www.APRegistry.com). Health care providers caring for pregnant females living with HIV and their infants may contact the National Perinatal HIV Hotline (1-888-448-8765) for clinical consultation (HHS [perinatal] 2019).

Patient Education

What is this drug used for?

• It is used to treat HIV infection.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Abdominal pain

• Nausea

• Vomiting

• Loss of strength and energy

• Diarrhea

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Infection

• Liver problems like dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin

• High blood sugar like confusion, fatigue, increased thirst, increased hunger, passing a lot of urine, flushing, fast breathing, or breath that smells like fruit

• Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight

• Dizziness

• Passing out

• Fast heartbeat

• Abnormal heartbeat

• Change in body fat

• Stevens-Johnson syndrome/toxic epidermal necrolysis like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in mouth, throat, nose, or eyes

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.