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Saquinavir

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.

Capsule, Oral:

Invirase: 200 mg

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 of HIV-1 infection in adults (>16 years); used in combination with ritonavir and other antiretroviral agents

Contraindications

Hypersensitivity (eg, anaphylactic reaction, Stevens-Johnson syndrome) to saquinavir, saquinavir mesylate, or any component of the formulation; congenital or acquired 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 alfuzosin, amiodarone, atazanavir, bepridil, chlorpromazine, cisapride, clarithromycin, clozapine, dapsone, disopyramide, dofetilide, ergot derivatives (dihydroergotamine, ergonovine, ergotamine, methylergonovine), erythromycin, flecainide, halofantrine, haloperidol, lidocaine (systemic), lovastatin, midazolam (oral), pentamidine, phenothiazines, pimozide, propafenone, quinidine, quinine, rifampin, sertindole, sildenafil (when used for pulmonary artery hypertension [eg, Revatio]), simvastatin, tacrolimus, thioridazine, trazodone, triazolam, or ziprasidone.

Canadian labeling: Additional contraindications (not in U.S. 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

Dosing: Adult

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.

HIV-1 infection: 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 (US labeling): 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.

Treatment-naive patients (Canadian labeling): Note: Patients with recent exposure (without washout) to a ritonavir or non-nucleoside reverse transcriptase inhibitor based regimen 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.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

HIV-1 infection: Oral:

Children ≥2 years and Adolescents <16 years (off-label dosing) (HHS [pediatric] 2015):

5 kg to <15 kg: Saquinavir 50 mg/kg/dose (maximum single dose: 1,000 mg) plus ritonavir 3 mg/kg/dose twice daily

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

≥40 kg: Saquinavir 1,000 mg plus ritonavir 100 mg twice daily

Adolescents >16 years: Refer to adult dosing.

Dosing: Renal Impairment

No dosage adjustment necessary; use with caution in severe renal impairment or ESRD (has not been studied).

Dosing: Hepatic Impairment

Mild to moderate impairment (Child-Pugh classes A and B): No dosage adjustment necessary.

Severe impairment (Child-Pugh class C): Use is contraindicated.

Administration

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.

Dietary Considerations

Take within 2 hours of a meal. Invirase capsules and tablets contain lactose (not expected to induce symptoms of intolerance).

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

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. Avoid combination

Afatinib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Afatinib. Management: Per US labeling: reduce afatinib by 10mg if not tolerated. Per Canadian labeling: avoid combination if possible; if used, administer the P-gp inhibitor simultaneously with or after the dose of afatinib. Consider therapy modification

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

Alfuzosin: Protease Inhibitors 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 adult dose to 6.25 mg and maximum adult dose to 12.5 mg/24-hrs 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: Protease Inhibitors may increase the serum concentration of ALPRAZolam. Management: Seek alternatives to alprazolam in patients treated with HIV protease inhibitors. Concurrent use of alprazolam with indinavir is contraindicated. All patients receiving such a combination should be monitored closely for excessive response to alprazolam. Consider therapy modification

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

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

Apixaban: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Apixaban. Management: US labeling recommends a 50% apixaban dose reduction in patients who would otherwise receive 5 or 10 mg twice daily, and avoiding in patients who would otherwise receive 2.5 mg twice daily. Canadian labeling lists any combined use as contraindicated. Consider therapy modification

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: 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: Please refer to the full interaction monograph for details concerning the recommended dose adjustments. Consider therapy modification

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

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

AtorvaSTATin: Protease Inhibitors may increase the serum concentration of AtorvaSTATin. Management: See full monograph for recommended dose limits. Avoid atorvastatin with tipranavir/ritonavir. Consider therapy modification

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

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

Bedaquiline: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bedaquiline. Management: Limit the duration of concomitant administration of bedaquiline with CYP3A4 inhibitors to no more than 14 days, unless the benefit of continued administration is judged to outweigh the possible risks. Monitor for toxic effects of bedaquiline. Consider therapy modification

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

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

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

Boceprevir: May decrease the serum concentration of Protease Inhibitors. Protease Inhibitors may decrease the serum concentration of Boceprevir. Management: Some combinations are not recommended. See full drug interaction monograph for details. Consider therapy modification

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

Bosentan: May decrease the serum concentration of Saquinavir. Saquinavir may increase the serum concentration of Bosentan. Management: Use bosentan 62.5 mg/day or every other day in adult patients taking saquinavir/ritonavir for at least 10 days. Temporarily stop bosentan (for at least 36 hrs) before starting saquinavir/ritonavir; wait at least 10 days before restarting bosentan. Consider therapy modification

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

Bosutinib: P-glycoprotein/ABCB1 Inhibitors 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

Brentuximab Vedotin: P-glycoprotein/ABCB1 Inhibitors 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 to 50% of usual with a strong CYP3A4 inhibitor; reduce to 25% of usual if used with both a moderate CYP3A4 inhibitor and a CYP2D6 inhibitor, or if a strong CYP3A4 inhibitor is used in a CYP2D6 poor metabolizer. Consider therapy modification

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

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

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). Avoid combination

Budesonide (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Topical). Management: Per US prescribing information, avoid this combination. Canadian product labeling does not recommend strict avoidance. If combined, monitor for excessive glucocorticoid effects as budesonide exposure may be increased. 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, cabozantinib dose adjustments are recommended and vary based on the cabozantinib product used and the indication for use. See monograph for details. 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

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

CarBAMazepine: May increase the metabolism of Protease Inhibitors. Protease Inhibitors may decrease the metabolism of CarBAMazepine. Consider therapy modification

Cariprazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cariprazine. Management: Cariprazine dose reductions of 50% are required; specific recommended management varies slightly for those stable on cariprazine versus those just starting cariprazine. See prescribing information or full interaction monograph for details. Consider therapy modification

Ceritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ceritinib. Management: If such combinations cannot be avoided, the ceritinib dose should be reduced by approximately one-third (to the nearest 150 mg). Resume the prior ceritinib dose after cessation of the strong CYP3A4 inhibitor. Avoid combination

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

Cisapride: Protease Inhibitors may increase the serum concentration of Cisapride. This may result in QTc prolongation and malignant cardiac arrhythmias. Avoid combination

Clarithromycin: Protease Inhibitors may diminish the therapeutic effect of Clarithromycin. Specifically, certain protease inhibitors may decrease formation of the active 14-hydroxy-clarithromycin metabolite, which may negatively impact clarithromycin effectiveness vs. H. influenzae and other non-MAC infections. Protease Inhibitors may increase the serum concentration of Clarithromycin. Clarithromycin dose adjustment in renally impaired patients may be needed. Clarithromycin may increase the serum concentration of Protease Inhibitors. Management: Avoid clarithromycin adult doses greater than 1000 mg/day when used with a protease inhibitor. Further dose reductions may be needed in patients with impaired renal function. Consider alternative antimicrobial for any non-MAC infection. Consider therapy modification

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

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

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. Consider therapy modification

Colchicine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Colchicine. Colchicine distribution into certain tissues (e.g., brain) may also be increased. Management: Colchicine is contraindicated in patients with impaired renal or hepatic function who are also receiving a p-glycoprotein inhibitor. In those with normal renal and hepatic function, reduce colchicine dose as directed. Consider therapy modification

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

Contraceptives (Estrogens): Protease Inhibitors may decrease the serum concentration of Contraceptives (Estrogens). 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

Contraceptives (Progestins): Saquinavir may decrease the serum concentration of Contraceptives (Progestins). 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

Corticosteroids (Orally Inhaled): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Corticosteroids (Orally Inhaled). Management: Orally inhaled fluticasone propionate with a strong CYP3A4 inhibitor is not recommended. Exceptions: Beclomethasone (Oral Inhalation); Triamcinolone (Systemic). Monitor therapy

Corticosteroids (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Corticosteroids (Systemic). Exceptions: MethylPREDNISolone; PrednisoLONE (Systemic); PredniSONE. Monitor therapy

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

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): Protease Inhibitors may increase the serum concentration of CycloSPORINE (Systemic). CycloSPORINE (Systemic) may increase the serum concentration of Protease Inhibitors. Consider therapy modification

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

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates. 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: CYP3A4 Inhibitors (Strong) may decrease the metabolism of CYP3A4 Substrates. Exceptions: Alitretinoin (Systemic); AmLODIPine; Buprenorphine; Gefitinib; HYDROcodone; Praziquantel; Telithromycin; Vinorelbine. Consider therapy modification

Dabigatran Etexilate: P-glycoprotein/ABCB1 Inhibitors may increase serum concentrations of the active metabolite(s) of Dabigatran Etexilate. Management: Dabigatran dose reductions may be needed. Specific recommendations vary considerably according to US vs Canadian labeling, specific P-gp inhibitor, renal function, and indication for dabigatran treatment. Refer to full monograph or dabigatran labeling. 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

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

Dasatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dasatinib. Management: Use of this combination should be avoided; consider reducing dasatinib dose if a strong CYP3A4 inhibitor must be used. If using dasatinib 100 mg/day, consider reduction to 20 mg/day; if using dasatinib 140 mg/day, consider reduction to 40 mg/day. Consider therapy modification

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Delavirdine: Protease Inhibitors may decrease the serum concentration of Delavirdine. Delavirdine may increase the serum concentration of Protease Inhibitors. Consider therapy modification

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

Digoxin: Protease Inhibitors may increase the serum concentration of Digoxin. Increased serum concentrations of digoxin may increase risk of AV nodal blockade. Monitor therapy

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

Domperidone: CYP3A4 Inhibitors (Strong) 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. One U.S. manufacturer (Pfizer Inc.) recommends that these combinations be avoided. Consider therapy modification

DOXOrubicin (Conventional): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to P-glycoprotein inhibitors in patients treated with doxorubicin whenever possible. One U.S. manufacturer (Pfizer Inc.) recommends that these combinations be avoided. Consider therapy modification

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

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

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

Edoxaban: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Edoxaban. Management: See full monograph for details. Reduced doses are recommended for patients receiving edoxaban for venous thromboembolism in combination with certain inhibitors. Similar dose adjustment is not recommended for edoxaban use in atrial fibrillation. 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

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

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

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

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates. 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

Ergot Derivatives: Protease Inhibitors may increase the serum concentration of Ergot Derivatives. Exceptions: Nicergoline. 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

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

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. Avoid combination

FentaNYL: CYP3A4 Inhibitors (Strong) may increase the serum concentration of FentaNYL. Management: Monitor patients closely for several days following initiation of this combination, and adjust fentanyl dose as necessary. Consider therapy modification

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

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

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

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

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

Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Oral Inhalation). Management: Use of orally inhaled fluticasone propionate with strong CYP3A4 inhibitors is not recommended. Use of orally inhaled fluticasone furoate with strong CYP3A4 inhibitors should be done with caution. Monitor patients using such a combination more closely. Consider therapy modification

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

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

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 guanfacine dose by 50% when initiating this combination. Consider therapy modification

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

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

Highest Risk QTc-Prolonging Agents: Moderate Risk QTc-Prolonging Agents may enhance the QTc-prolonging effect of Highest Risk QTc-Prolonging Agents. Avoid combination

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

Ibrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ibrutinib. Management: If a strong CYP3A inhibitor must be used short-term (e.g. antifungals and antibiotics for 7 days or less), consider stopping ibrutinib until the CYP3A inhibitor is no longer needed. 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

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

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

Ivabradine: May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Avoid combination

Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivacaftor. Management: Ivacaftor dose reductions are required; consult prescribing information for specific age- and weight-based recommendations. Consider therapy modification

Ixabepilone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ixabepilone. 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

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

Lapatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lapatinib. Management: If an overlap in therapy cannot be avoided, consider reducing lapatinib adult dose to 500 mg/day during, and within 1 week of completing, treatment with the strong CYP3A4 inhibitor. Avoid combination

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

Levobupivacaine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levobupivacaine. 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: Saquinavir may enhance the QTc-prolonging effect of Lopinavir. Avoid combination

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

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

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

Maraviroc: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Maraviroc. Management: Reduce the adult dose of maraviroc to 150 mg twice daily when used with a strong CYP3A4 inhibitor. Do not use maraviroc with strong CYP3A4 inhibitors in patients with Clcr less than 30 mL/min. Consider therapy modification

Meperidine: Protease Inhibitors may enhance the adverse/toxic effect of Meperidine. Protease Inhibitors may decrease the serum concentration of Meperidine. Concentrations of the toxic Normeperidine metabolite may be increased. Consider therapy modification

Methadone: May enhance the QTc-prolonging effect of Saquinavir. Saquinavir may decrease the serum concentration of Methadone. Management: Use methadone and saquinavir cautiously in combination, seeking alternatives when possible due to the potential for excessive QT interval prolongation and associated arrhythmias. Consider therapy modification

MethylPREDNISolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MethylPREDNISolone. Management: Consider methylprednisolone dose reduction in patients receiving strong CYP3A4 inhibitors and monitor for increased steroid related adverse effects. 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

MiFEPRIStone: May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Avoid combination

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

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

Moderate Risk QTc-Prolonging Agents: May enhance the QTc-prolonging effect of other Moderate Risk QTc-Prolonging Agents. Management: Avoid such combinations when possible. Use should be accompanied by close monitoring for evidence of QT prolongation or other alterations of cardiac rhythm. Consider therapy modification

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

Nevirapine: May decrease the serum concentration of Saquinavir. Monitor therapy

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

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

Nintedanib: Combined Inhibitors of CYP3A4 and P-glycoprotein may increase the serum concentration of Nintedanib. Monitor therapy

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 in patients being treated with olaparib. If such concurrent use cannot be avoided, the dose of olaparib should be reduced to 150 mg twice daily. Avoid combination

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

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

OxyCODONE: CYP3A4 Inhibitors (Strong) may enhance the adverse/toxic effect of OxyCODONE. CYP3A4 Inhibitors (Strong) may increase the serum concentration of OxyCODONE. Serum concentrations of the active metabolite oxymorphone may also be increased. Consider therapy modification

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

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. Consider therapy modification

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

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

PAZOPanib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of PAZOPanib. Avoid combination

P-glycoprotein/ABCB1 Inhibitors: May increase the serum concentration of P-glycoprotein/ABCB1 Substrates. P-glycoprotein inhibitors may also enhance the distribution of p-glycoprotein substrates to specific cells/tissues/organs where p-glycoprotein is present in large amounts (e.g., brain, T-lymphocytes, testes, etc.). Monitor therapy

P-glycoprotein/ABCB1 Substrates: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of P-glycoprotein/ABCB1 Substrates. P-glycoprotein inhibitors may also enhance the distribution of p-glycoprotein substrates to specific cells/tissues/organs where p-glycoprotein is present in large amounts (e.g., brain, T-lymphocytes, testes, etc.). Monitor therapy

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

PONATinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PONATinib. Management: Per ponatinib U.S. prescribing information, the adult starting dose of ponatinib should be reduced to 30 mg daily during treatment with any strong CYP3A4 inhibitor. Consider therapy modification

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

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

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

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

Prucalopride: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Prucalopride. Monitor therapy

QTc-Prolonging Agents (Indeterminate Risk and Risk Modifying): May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Monitor therapy

QuiNIDine: Saquinavir may enhance the QTc-prolonging effect of QuiNIDine. Saquinavir may increase the serum concentration of QuiNIDine. 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

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

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

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

RifAXIMin: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of RifAXIMin. Monitor therapy

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

Riociguat: Protease Inhibitors may increase the serum concentration of Riociguat. Management: Consider starting with a reduced riociguat dose of 0.5 mg three times a day (for adults). Patients receiving such a combination should also be monitored extra closely for signs or symptoms of hypotension. Consider therapy modification

Rivaroxaban: Inhibitors of CYP3A4 (Strong) and P-glycoprotein may increase the serum concentration of Rivaroxaban. Avoid combination

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

Rosuvastatin: Protease Inhibitors may increase the serum concentration of Rosuvastatin. Management: Start at the lowest rosuvastatin dose and monitor for toxicity. See full drug interaction monograph for details. Consider therapy modification

Ruxolitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ruxolitinib. Management: This combination should be avoided under some circumstances. See monograph for details. Consider therapy modification

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

SAXagliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SAXagliptin. Management: Saxagliptin U.S. product labeling recommends limiting saxagliptin adult dose to 2.5 mg/day when used with a strong CYP3A4 inhibitor. Monitor for increased saxagliptin levels/effects. A similar recommendation is not made in the Canadian product labeling. Consider therapy modification

Sildenafil: Saquinavir may increase the serum concentration of Sildenafil. Management: Used for PAH: no dose adjustment recommended per US label, Canadian label recommends decrease to 20 mg twice/day. Used for ED: 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

Silodosin: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Silodosin. Avoid combination

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates. 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

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

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

Tacrolimus (Systemic): Protease Inhibitors may decrease the metabolism of Tacrolimus (Systemic). Consider therapy modification

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

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: Recommendations regarding use of tadalafil in patients also receiving strong CYP3A4 inhibitors may vary based on indication and/or international labeling. Consult appropriate product labeling. 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

Temsirolimus: Protease Inhibitors may enhance the adverse/toxic effect of Temsirolimus. Levels of sirolimus, the active metabolite, may be increased, likely due to inhibition of CYP-mediated metabolism. Consider therapy modification

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

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

Theophylline Derivatives: Protease Inhibitors may decrease the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline. Monitor therapy

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. Monitor therapy

Tofacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tofacitinib. Management: Reduce the adult dose of tofacitinib to 5 mg daily in patients receiving strong CYP3A4 inhibitors. Consider therapy modification

Tolterodine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolterodine. Management: The maximum recommended adult dose of tolterodine is 2 mg/day when used together with a strong CYP3A4 inhibitor. Consider therapy modification

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

Topotecan: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Topotecan. Avoid combination

Toremifene: CYP3A4 Inhibitors (Strong) may enhance the adverse/toxic effect of Toremifene. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Toremifene. Avoid combination

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

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

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

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

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: Recommendations regarding concomitant use of vardenafil with strong CYP3A4 inhibitors may vary depending on brand name (e.g., Levitra, Staxyn) or by international labeling. See full drug interaction monograph for details. Consider therapy modification

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

Venetoclax: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Venetoclax. Management: These combinations are contraindicated during venetoclax initiation and ramp-up. In patients receiving steady venetoclax doses after completing ramp-up, reduce the venetoclax by at least 75% if strong CYP3A4 inhibitor use cannot be avoided. Consider therapy modification

Venetoclax: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Venetoclax. Management: Reduce the venetoclax dose by at least 50% in patients requiring these combinations. Consider therapy modification

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

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

VinCRIStine (Liposomal): P-glycoprotein/ABCB1 Inhibitors 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

Vinflunine: May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. 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

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

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: The initial starting adult dose of zopiclone should not exceed 3.75 mg if combined with a strong CYP3A4 inhibitor. Monitor patients for signs and symptoms of zopiclone toxicity if these agents are combined. Consider therapy modification

Adverse Reactions

Incidence data shown 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%), fever (3%), anxiety, depression, headache, insomnia, pain

Dermatologic: Pruritus (3%), rash (3%), dry lips/skin (2%), eczema (2%), verruca

Endocrine & metabolic: Lipodystrophy (5%), hyperglycemia (3%), hypoglycemia, hyperkalemia, libido disorder, serum amylase increased

Gastrointestinal: Diarrhea (8%), vomiting (7%), abdominal pain (6%), constipation (2%), abdominal discomfort, appetite decreased, buccal mucosa ulceration, dyspepsia, flatulence, taste alteration

Hepatic: AST increased, ALT increased, bilirubin increased

Neuromuscular & skeletal: Back pain (2%), CPK increased, paresthesia, weakness

Renal: Creatinine kinase increased

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

Miscellaneous: Influenza (3%)

Incidence not currently defined (limited to significant reactions; reported for hard or soft gel capsule with/without ritonavir)

Cardiovascular: Cyanosis, heart valve disorder (including murmur), hyper-/hypotension, peripheral vasoconstriction, prolonged QT interval, prolonged PR interval, syncope, thrombophlebitis

Central nervous system: Agitation, amnesia, ataxia, confusion, hallucination, hyper-/hyporeflexia, myelopolyradiculoneuritis, neuropathies, poliomyelitis, progressive multifocal encephalopathy, psychosis, seizures, somnolence, speech disorder, suicide attempt

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

Endocrine & metabolic: Dehydration, diabetes, electrolyte changes, TSH increased

Gastrointestinal: Ascites, colic, dysphagia, esophagitis, bloody stools, gastritis, intestinal obstruction, hemorrhage (rectal), pancreatitis, stomatitis

Genitourinary: impotence, prostate enlarged, hematuria, UTI

Hematologic; Acute myeloblastic leukemia, anemia (including hemolytic), leukopenia, neutropenia, pancytopenia, splenomegaly, thrombocytopenia

Hepatic: Alkaline phosphatase increased, GGT increased, hepatitis, hepatomegaly, hepatosplenomegaly, jaundice, liver disease exacerbation

Neuromuscular & skeletal: Arthritis, LDH increased

Ocular: Blepharitis, visual disturbance

Otic: Otitis, hearing decreased, tinnitus

Renal: Nephrolithiasis, renal calculus

Respiratory: Dyspnea, hemoptysis, pharyngitis, upper respiratory tract infection

Miscellaneous: Immune reconstitution syndrome, infections (bacterial, fungal, viral)

Postmarketing and/or case reports: AV block (second or third degree), torsade 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 >480 msec or 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.

• 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) (DHHS [pediatric], 2015).

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: May cause hepatitis and/or exacerbate preexisting hepatic dysfunction; use with caution in patients with underlying mild-to-moderate hepatic disease, including hepatitis B or C, cirrhosis, or chronic alcoholism; contraindicated in severe hepatic impairment.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Dosage forms specific issues:

• Lactose: Formulation contains lactose; Canadian product labeling recommends against use in patients with galactose intolerance, Lapp lactase deficiency or 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

Pregnancy Risk Factor

B

Pregnancy Considerations

Adverse events were not observed in animal reproduction studies; data collected by the antiretroviral pregnancy registry is insufficient to evaluate human teratogenic risk. Saquinavir has a low level of transfer across the human placenta. A small increased risk of preterm birth has been associated with maternal use of protease inhibitor-based combination antiretroviral (ARV) therapy during pregnancy; however, the benefits of use generally outweigh this risk and protease inhibitors (PIs) should not be withheld if otherwise recommended. Hyperglycemia, new onset of diabetes mellitus, or diabetic ketoacidosis have been reported with PIs; it is not clear if pregnancy increases this risk. The HHS Perinatal HIV Guidelines do not recommend ritonavir-boosted saquinavir for use in antiretroviral-naive pregnant women due to potential toxicity, twice-daily dosing requirements, and limited data in pregnancy; use of saquinavir without ritonavir is not recommended in any patient. Based on available data, dose adjustments are not required in pregnant women.

Combination antiretroviral therapy (cART) therapy is recommended for all HIV-infected pregnant women. The goal of therapy is to keep the viral load below the limit of detection and prevent perinatal transmission. Therapy must be individualized. In general, women who become pregnant on a stable cART regimen may continue that regimen if viral suppression is effective, contraindications for use in pregnancy are not present, and the regimen is well tolerated. For HIV-infected couples planning a pregnancy, maximum viral suppression with cART is recommended prior to conception for the HIV-infected partner(s). When HIV is diagnosed during pregnancy in a woman who has never received antiretroviral therapy, cART should be considered as soon as possible after diagnosis to reduce the risk of perinatal transmission. If antiretroviral drug-resistance testing is done, treatment may be started prior to obtaining results, then adjusted accordingly. Monitoring during pregnancy is more frequent than in non-pregnant adults. If cART must be interrupted for <24 hours, stop then restart all medications simultaneously in order to decrease the chance of developing resistance. Long-term follow-up is recommended for all infants exposed to antiretroviral medications; children who develop significant organ system abnormalities (particularly of the CNS or heart) should be evaluated for potential mitochondrial dysfunction.

HIV-infected women not planning a pregnancy may use any available type of contraception, considering possible drug interactions and contraindications of the specific method. In addition, consistent use of condoms is also recommended (even during pregnancy) to prevent transmission of HIV or other sexually-transmitted diseases.

Health care providers are encouraged to enroll pregnant women exposed to antiretroviral medications as early in pregnancy as possible in the Antiretroviral Pregnancy Registry (1-800-258-4263 or www.APRegistry.com). Health care providers caring for HIV-infected women and their infants may contact the National Perinatal HIV Hotline (888-448-8765) for clinical consultation (HHS [perinatal] 2016).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience nausea, vomiting, or diarrhea. Have patient report immediately to prescriber signs of infection, signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), signs of high blood sugar (confusion, feeling sleepy, more thirst, hunger, passing urine more often, flushing, fast breathing, or breath that smells like fruit), signs of depression (suicidal ideation, anxiety, emotional instability, or illogical thinking), signs of severe cerebrovascular disease (change in strength on one side is greater than the other, trouble speaking or thinking, change in balance, or change in eyesight), severe dizziness; passing out; angina; tachycardia; bradycardia; arrhythmia; severe loss of strength and energy; black, tarry, or bloody stools; vomiting blood; burning or numbness feeling; coughing up blood; flu-like symptoms; seizures; severe headache; shortness of breath; swelling of arms or legs; bruising; bleeding; severe abdominal pain; change in body fat; or signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes) (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

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