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Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir Alafenamide

Pronunciation

(el vi TEG ra vir, koe BIK i stat, em trye SYE ta been, & ten OF oh vir al a FEN a mide)

Index Terms

  • Cobicistat, Emtricitabine, Tenofovir Alafenamide, and Elvitegravir
  • Elviteg/Cobi/Emtric/Tenofo Ala
  • Elvitegravir, Cobicistat, Tenofovir Alafenamide, and Emtricitabine
  • Emtricitabine, Elvitegravir, Cobicistat, and Tenofovir Alafenamide
  • Tenofovir Alafenamide, Elvitegravir, Cobicistat, and Emtricitabine

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Genvoya: Elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg, and tenofovir alafenamide 10 mg [contains fd&c blue #2 aluminum lake]

Brand Names: U.S.

  • Genvoya

Pharmacologic Category

  • Antiretroviral, Integrase Inhibitor (Anti-HIV)
  • Antiretroviral, Reverse Transcriptase Inhibitor, Nucleoside (Anti-HIV)
  • Antiretroviral, Reverse Transcriptase Inhibitor, Nucleotide (Anti-HIV)
  • Cytochrome P-450 Inhibitor

Pharmacology

Integrase strand transfer inhibitor, CYP3A enzyme inhibitor plus nucleoside and nucleotide reverse transcriptase inhibitor combination; the viral cDNA strand produced by reverse transcriptase is processed and inserted into the human genome by the enzyme HIV-1 integrase. Elvitegravir inhibits the catalytic activity of integrase, thus preventing integration of the proviral gene into human DNA. Cobicistat inhibits enzymes of the CYP3A subfamily and enhances systemic exposure to elvitegravir. Emtricitabine is a cytosine analogue and tenofovir alafenamide is converted to tenofovir in vivo; tenofovir is an analog of adenosine 5'-monophosphate. Emtricitabine and tenofovir interfere with HIV viral RNA dependent DNA polymerase activities resulting in inhibition of viral replication.

Absorption

AUC of elvitegravir increases with food; emtricitabine, tenofovir alafenamide and cobicistat not affected

Metabolism

Elvitegravir: By CYP3A enzymes and also hepatic glucuronidation mediated by UGT1A1/3

Cobicistat: By CYP3A enzymes and to a minor extent CYP2D6

Emtricitabine: Not significantly metabolized

Tenofovir alafenamide: Primarily intracellular metabolism; minimal extent by CYP3A

Excretion

Elvitegravir: Feces (~95%), urine (~7%); Cobicistat: Feces (~86%), urine (~8%); Emtricitabine: Feces (~14%), urine (70%); Tenofovir: Feces (~32%), urine (<1%)

Time to Peak

~3 hours (component range: 1 to 4 hours)

Half-Life Elimination

Elvitegravir: ~13 hours; Cobicistat: ~4 hours; Emtricitabine: ~10 hours; Tenofovir alafenamide: ~0.51 hours

Protein Binding

Elvitegravir: ~99%; Cobicistat: ~98%; Emtricitabine: <4%; Tenofovir alafenamide: ~80%

Use: Labeled Indications

HIV-1 infection:

US labeling: Treatment of HIV-1 infection in adults and pediatric patients 12 years of age and older who have no antiretroviral treatment history or to replace the current antiretroviral regimen in those who are virologically-suppressed (HIV-1 RNA less than 50 copies per mL) on a stable antiretroviral regimen for at least 6 months with no history of treatment failure and no known substitutions associated with resistance to elvitegravir, cobicistat, emtricitabine, or tenofovir alafenamide

Canadian labeling: Treatment of HIV-1 infection in adults and pediatric patients 12 years of age and older and with no known mutations associated with resistance to elvitegravir, cobicistat, emtricitabine, or tenofovir alafenamide

Contraindications

Coadministration with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events, including (but may not be limited to): alfuzosin, carbamazepine, cisapride, ergot derivatives (eg, dihydroergotamine, ergonovine, ergotamine, methylergonovine), lovastatin, midazolam (oral), phenobarbital, phenytoin, pimozide, rifampin, sildenafil (for the treatment of pulmonary arterial hypertension), simvastatin, St John's wort, or triazolam

Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to elvitegravir, cobicistat, emtricitabine, tenofovir alafenamide, or any component of the formulation; coadministration with salmeterol, astemizole (not available in Canada), or terfenadine (not available in Canada).

Dosing: Adult

Note: Prior to initiation, patients should be tested for hepatitis B infection, and baseline estimated creatinine clearance, urine glucose, and urine protein should be assessed in all patients.

HIV-1: Oral: One tablet once daily.

Missed dose: If a missed dose is remembered within 18 hours of the usual administration time, administer the missed dose as soon as possible and resume regular administration schedule. If a dose is missed by >18 hours, do not administer missed dose and resume dosing at usual administration time.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Prior to initiation, patients should be tested for hepatitis B infection, and baseline estimated creatinine clearance, urine glucose, and urine protein should be assessed in all patients.

HIV-1: Children and Adolescents ≥12 years and ≥35 kg: Oral: Refer to adult dosing

Dosing: Renal Impairment

CrCl ≥30 mL/minute: No dosage adjustment necessary.

CrCl <30 mL/minute at initiation of therapy: Use is not recommended.

Dosing: Hepatic Impairment

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

Severe impairment (Child-Pugh class C): Use is not recommended (has not been studied).

Administration

Oral: Administer with food. Do not use if seal over bottle opening is broken or missing.

Dietary Considerations

Take with food. Consider calcium and vitamin D supplementation in all patients.

Storage

Store below 30°C (86°F); dispense in original container.

Drug Interactions

Acyclovir-Valacyclovir: May increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Acyclovir-Valacyclovir. Monitor therapy

Adefovir: May diminish the therapeutic effect of Tenofovir Products. Adefovir may increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Adefovir. 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. 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

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

Aminoglycosides: May increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Aminoglycosides. Monitor therapy

Amiodarone: Cobicistat may increase the serum concentration of Amiodarone. Monitor therapy

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

Antacids: May decrease the serum concentration of Elvitegravir. Management: Separate administration of antacids and elvitegravir-containing products by at least 2 hours in order to minimize the risk for an interaction. Consider therapy modification

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

Asunaprevir: OATP1B1/SLCO1B1 Inhibitors may increase the serum concentration of Asunaprevir. Avoid combination

Atazanavir: May increase the serum concentration of Elvitegravir. Specifically, atazanavir/ritonavir may increase the concentration of elvitegravir. Management: When elvitegravir is combined with atazanavir/ritonavir, the dose of elvitegravir should be reduced to 85 mg once daily and the dose of atazanavir/ritonavir should be 300 mg/100 mg once daily. Avoid the use of atazanavir/cobicistat and elvitegravir. Consider therapy modification

AtorvaSTATin: Cobicistat may increase the serum concentration of AtorvaSTATin. Management: Initiate atorvastatin at the lowest recommended dose and titrate slowly as needed while monitoring closely for evidence of atorvastatin toxicity. 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

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

Boceprevir: Cobicistat may increase the serum concentration of Boceprevir. Management: Avoid concomitant use of boceprevir with cobicistat. US prescribing information for the combination product containing elvitegravir, cobicistat, emtricitabine, and tenofovir does not address this potential interaction. Avoid combination

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

Bosentan: Cobicistat may increase the serum concentration of Bosentan. Management: See full drug interaction monograph for details. 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): Cobicistat may increase the serum concentration of Budesonide (Nasal). Management: Consider an alternative nasal corticosteroid when possible, particularly for longer-term concurrent use. If this combination must be used, monitor patients closely for evidence of systemic corticosteroid effects including adrenal suppression. Consider therapy modification

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

Buprenorphine: Cobicistat may increase the serum concentration of Buprenorphine. Monitor therapy

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

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 decrease the serum concentration of Cobicistat. Avoid combination

CarBAMazepine: May decrease the serum concentration of Elvitegravir. Avoid combination

CarBAMazepine: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

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

Cidofovir: May increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Cidofovir. 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

Cisapride: Cobicistat may increase the serum concentration of Cisapride. Avoid combination

Clarithromycin: May increase the serum concentration of Cobicistat. Cobicistat may increase the serum concentration of Clarithromycin. Management: Consider alternative antibiotics. Reduce clarithromycin dose by 50% in patients receiving elvitegravir/cobicistat/emtricitabine/tenofovir with estimated creatinine clearance 50 to 60 mL/min. Closely monitor for clarithromycin toxicity. Consider therapy modification

ClonazePAM: Cobicistat may increase the serum concentration of ClonazePAM. Monitor therapy

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

Cobicistat: May enhance the adverse/toxic effect of Tenofovir Products. More specifically, cobicistat may impair proper tenofovir monitoring and dosing. Monitor therapy

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): Cobicistat may decrease the serum concentration of Contraceptives (Estrogens). Management: Consider an alternative, non-hormone-based contraceptive in patients receiving cobicistat-containing products. Consider therapy modification

Contraceptives (Estrogens): Elvitegravir may decrease the serum concentration of Contraceptives (Estrogens). Management: Consider the use of an alternative, non-hormone-based contraceptive, in patients who are being treated with elvitegaravir-containing products. Consider therapy modification

Contraceptives (Progestins): Cobicistat may increase the serum concentration of Contraceptives (Progestins). Management: Consider an alternative, non-hormone-based contraceptive in patients receiving cobicistat-containing products. 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

CYP2D6 Substrates: Cobicistat may increase the serum concentration of CYP2D6 Substrates. Monitor therapy

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: May increase the serum concentration of Elvitegravir. Management: When elvitegravir is combined with darunavir/ritonavir, the dose of elvitegravir should remain 150 mg once daily and the dose of darunavir/ritonavir should be 600 mg/100 mg twice daily. Avoid the combination of darunavir/cobicistat and elvitegravir. Consider therapy modification

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

Dexamethasone (Systemic): May decrease the serum concentration of Elvitegravir. Management: Consider using an alternative corticosteroid. Monitor patients receiving these agents in combination for diminished antiviral response. Consider therapy modification

Dexamethasone (Systemic): May decrease the serum concentration of Cobicistat. Dexamethasone (Systemic) may also counteract the boosting effects of Cobicistat on some agents. Management: Consider an alternative corticosteroid. Monitor patients receiving this combination closely for evidence of diminished response to the antiviral regimen. Consider therapy modification

Diclofenac (Systemic): May enhance the nephrotoxic effect of Tenofovir Products. Management: Seek alternatives to this combination whenever possible. Avoid use of tenofovir with multiple NSAIDs or any NSAID given at a high dose. Consider therapy modification

Dihydroergotamine: Cobicistat may increase the serum concentration of Dihydroergotamine. Avoid combination

Dofetilide: Cobicistat may increase the serum concentration of Dofetilide. Monitor therapy

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: May decrease the serum concentration of Elvitegravir. Avoid combination

Elbasvir: Cobicistat may increase the serum concentration of Elbasvir. Avoid combination

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

Eliglustat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eliglustat. Management: Use should be avoided under some circumstances. See full drug interaction monograph for details. Consider therapy modification

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

Ergotamine: Cobicistat may increase the serum concentration of Ergotamine. 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

Ethosuximide: Cobicistat may increase the serum concentration of Ethosuximide. Monitor therapy

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

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

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

Fluticasone (Nasal): Cobicistat may increase the serum concentration of Fluticasone (Nasal). Management: Consider an alternative nasal corticosteroid when possible, particularly for longer-term concurrent use. Consider therapy modification

Fluticasone (Oral Inhalation): Cobicistat may increase the serum concentration of Fluticasone (Oral Inhalation). Avoid combination

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

Fosphenytoin-Phenytoin: May decrease the serum concentration of Cobicistat. Avoid combination

Fosphenytoin-Phenytoin: May decrease the serum concentration of Elvitegravir. Avoid combination

Fosphenytoin-Phenytoin: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

Ganciclovir-Valganciclovir: May enhance the adverse/toxic effect of Reverse Transcriptase Inhibitors (Nucleoside). Hematologic toxicity with zidovudine is of particular concern. Ganciclovir-Valganciclovir may increase the serum concentration of Reverse Transcriptase Inhibitors (Nucleoside). Management: Monitor patients receiving any of these combination closely for toxicity of the reverse transcriptase inhibitor. Avoid zidovudine. Intravitreal implants would not be affected. Consider therapy modification

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

Grazoprevir: Cobicistat 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

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

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

Itraconazole: May increase the serum concentration of Elvitegravir. Management: Limit itraconazole to a maximum dose of 200 mg/day in patients who are being treated with the elvitegravir-containing products. Consider therapy modification

Itraconazole: May increase the serum concentration of Cobicistat. Cobicistat may increase the serum concentration of Itraconazole. Management: Limit itraconazole to a maximum adult dose of 200 mg/day in patients treated with the elvitegravir/cobicistat/emtricitabine/tenofovir combination product. Dosing recommendations for other cobicistat-containing products are not available. 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 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): May increase the serum concentration of Elvitegravir. Management: Limit ketoconazole to a maximum dose of 200 mg/day in patients who are being treated with an elvitegravir-containing product. Consider therapy modification

Ketoconazole (Systemic): May increase the serum concentration of Cobicistat. Cobicistat may increase the serum concentration of Ketoconazole (Systemic). Management: Limit ketoconazole to a maximum adult dose of 200 mg/day in patients being treated with the elvitegravir/cobicistat/emtricitabine/tenofovir combination product. Dosing recommendations for other cobicistat-containing products are not available. Consider therapy modification

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

LamiVUDine: May enhance the adverse/toxic effect of Emtricitabine. Avoid combination

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

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

Lopinavir: May increase the serum concentration of Elvitegravir. Specifically, lopinavir/ritonavir may increase the concentration of elvitegravir. Management: When elvitegravir is combined with lopinavir/ritonavir, the dose of elvitegravir should be reduced to 85 mg once daily and the dose of lopinavir/ritonavir should be 400 mg/100 mg twice daily. Consider therapy modification

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

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

Methadone: Cobicistat may increase the serum concentration of Methadone. Management: No increased monitoring appears necessary if the cobicistat regimen also contains elvitegravir. Monitor therapy

Methylergonovine: Cobicistat may increase the serum concentration of Methylergonovine. Avoid combination

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: Cobicistat may increase the serum concentration of Midazolam. Management: Oral midazolam use is contraindicated with cobicistat-containing products. IV midazolam should be used with caution, close monitoring, and consideration of lower IV midazolam doses. Avoid combination

MiFEPRIStone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MiFEPRIStone. Management: Limit mifepristone adult dose, when used for treatment of hyperglycemia in Cushing's syndrome, to a maximum of 300 mg/day when combined with a strong CYP3A4 inhibitor. Monitor for increased mifepristone toxicity regardless of dose or indication. 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

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

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

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

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

Nonsteroidal Anti-Inflammatory Agents: May enhance the nephrotoxic effect of Tenofovir Products. Management: Seek alternatives to these combinations whenever possible. Avoid use of tenofovir with multiple NSAIDs or any NSAID given at a high dose. Consider therapy modification

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

OXcarbazepine: May decrease the serum concentration of Elvitegravir. Management: For elvitegravir plus a ritonavir-boosted protease inhibitor, use of oxcarbazepine is not recommended; for elvitegravir/cobicistat/emtricitabine/tenofovir combination products, consider using an alternative antiepileptic when possible. Avoid combination

OXcarbazepine: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

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

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

PAZOPanib: BCRP/ABCG2 Inhibitors may increase the serum concentration of PAZOPanib. Avoid combination

Perhexiline: CYP2D6 Inhibitors (Weak) may increase the serum concentration of Perhexiline. 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

PHENobarbital: May decrease the serum concentration of Cobicistat. Avoid combination

PHENobarbital: May decrease the serum concentration of Elvitegravir. Avoid combination

PHENobarbital: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

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

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

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

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

Primidone: May decrease the serum concentration of Cobicistat. Avoid combination

Primidone: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

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

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

QUEtiapine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of QUEtiapine. Management: In quetiapine treated patients, reduce the quetiapine dose to one sixth of the regular dose following strong CYP3A4 inhibitor initiation. In patients receiving strong CYP3A4 inhibitors, initiate quetiapine at the lowest dose and up-titrate as needed. Consider therapy modification

QuiNIDine: Cobicistat may increase the serum concentration of QuiNIDine. Monitor therapy

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

Ribavirin (Oral Inhalation): May enhance the hepatotoxic effect of Reverse Transcriptase Inhibitors (Nucleoside). Monitor therapy

Ribavirin (Systemic): May enhance the hepatotoxic effect of Reverse Transcriptase Inhibitors (Nucleoside). Monitor therapy

Rifabutin: Elvitegravir may increase serum concentrations of the active metabolite(s) of Rifabutin. Rifabutin may decrease the serum concentration of Elvitegravir. Management: For single-agent elvitegravir, a rifabutin dose reduction of at least 75% is required (ie, reduction to adult dose of 150 mg every other day or three times/week). Use of elvitegravir combination products with rifabutin is not recommended. Avoid combination

Rifabutin: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

RifAMPin: May decrease the serum concentration of Elvitegravir. Avoid combination

RifAMPin: May decrease the serum concentration of Cobicistat. Avoid combination

RifAMPin: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

Rifapentine: May decrease the serum concentration of Cobicistat. Avoid combination

Rifapentine: May decrease the serum concentration of Elvitegravir. Avoid combination

Rifapentine: May decrease the serum concentration of Tenofovir Alafenamide. 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: Cobicistat may increase the serum concentration of Riociguat. Management: Consider starting with a reduced riociguat dose of 0.5 mg three times a day. Patients receiving such a combination should also be monitored extra closely for signs or symptoms of hypotension. Consider therapy modification

Ritonavir: Cobicistat may enhance the therapeutic effect of Ritonavir. Specifically, cobicistat and ritonavir have overlapping effects on the CYP3A4-mediated metabolism of other drugs. Avoid combination

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

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

Saquinavir: 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

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: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sildenafil. Management: Use of sildenafil for pulmonary hypertension should be avoided with strong CYP3A4 inhibitors. When used for erectile dysfunction, starting adult dose should be reduced to 25 mg. Maximum adult dose with ritonavir or cobicistat is 25 mg per 48 hours. 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

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 decrease the serum concentration of Cobicistat. Avoid combination

St John's Wort: May decrease the serum concentration of Elvitegravir. Avoid combination

St John's Wort: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination

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

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

Tadalafil: Cobicistat may increase the serum concentration of Tadalafil. Management: Recommendations for use of tadalafil in patients also receiving cobicistat vary by tadalafil indication and country. See full drug interaction monograph for details. 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

Telaprevir: Cobicistat may increase the serum concentration of Telaprevir. Management: Avoid concomitant use of telaprevir with cobicistat. This warning does not apply to use of the combination product containing elvitegravir, cobicistat, emtricitabine, and tenofovir. Avoid combination

Telithromycin: May increase the serum concentration of Cobicistat. Cobicistat may increase the serum concentration of Telithromycin. Management: Seek alternatives to telithromycin. US prescribing information for the combination product containing elvitegravir, cobicistat, emtricitabine, and tenofovir does not address this potential interaction. Consider therapy modification

Tenofovir Products: Cobicistat may enhance the adverse/toxic effect of Tenofovir Products. More specifically, cobicistat may impair proper tenofovir monitoring and dosing. Monitor therapy

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

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

Tipranavir: May decrease the serum concentration of Tenofovir Alafenamide. 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

Triazolam: Cobicistat may increase the serum concentration of Triazolam. 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

Vardenafil: Cobicistat may increase the serum concentration of Vardenafil. Management: Recommendations regarding use of vardenafil with cobicistat-containing products vary by vardenafil product and by country. 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

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: May increase the serum concentration of Elvitegravir. Management: Careful consideration of the risk/benefit ratio for voriconazole use is recommended prior to its use in patients treated with elvitegravir-containing products. Consider therapy modification

Voriconazole: May increase the serum concentration of Cobicistat. Cobicistat may increase the serum concentration of Voriconazole. Management: Careful consideration of the risk/benefit ratio for voriconazole use is recommended prior to its use in patients who are being treated with cobicistat-containing products. Consider therapy modification

Warfarin: Cobicistat may increase the serum concentration of Warfarin. 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

Zuclopenthixol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zuclopenthixol. Management: Consider zuclopenthixol dosage reduction with concomitant use of a strong CYP3A4 inhibitor (eg, ketoconazole) in poor CYP2D6 metabolizers or with strong CYP2D6 inhibitors (eg, paroxetine). Monitor for increased zuclopenthixol levels/toxicity. Consider therapy modification

Adverse Reactions

Frequency not always defined; includes data from both treatment-naive and treatment-experienced patients. Also see individual agents.

Central nervous system: Headache (6%), fatigue (5%)

Endocrine & metabolic: Increased HDL cholesterol, increased LDL cholesterol, increased serum cholesterol, increased serum triglycerides

Gastrointestinal: Nausea (10%), diarrhea (7%)

Neuromuscular & skeletal: Decreased bone mineral density (≥5% decrease at lumbar spine: 1% to 10%; ≥7% decrease at femoral neck: 1% to 7%), bone fracture (≤1%; excluding fingers and toes)

Renal: Increased serum creatinine (mean increase 0.1 mg/dL)

<1% (Limited to important or life-threatening): Exacerbation of hepatitis B

ALERT: U.S. Boxed Warning

Lactic acidosis/severe hepatomegaly with steatosis:

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs in combination with other antiretrovirals.

Post treatment acute exacerbation of hepatitis B:

This fixed-dose combination is not approved for the treatment of chronic hepatitis B virus (HBV) infection and the safety and efficacy have not been established in patients coinfected with human immunodeficiency virus-1 (HIV-1) and HBV. Severe, acute exacerbations of hepatitis B have been reported in patients who are coinfected with HIV-1 and HBV and have discontinued products containing emtricitabine and/or tenofovir disoproxil fumarate (TDF), and may occur with elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who are coinfected with HIV-1 and HBV and discontinue this fixed-dose combination. If appropriate, initiation of antihepatitis B therapy may be warranted.

Warnings/Precautions

Concerns related to adverse effects:

• Decreased bone mineral density: In clinical trials, tenofovir (both disoproxil fumarate and alafenamide) have been associated with decreases in bone mineral density in HIV-1 infected adults and pediatric patients ≥12 and <18 years and increases in bone metabolism markers. Consider monitoring of bone density in adult and pediatric patients with a history of pathologic fractures or with other risk factors for bone loss or osteoporosis; Canadian labeling recommends consideration of bone mineral density testing in pediatric patients ≥12 and <18 years. Consider calcium and vitamin D supplementation for all patients; effect of supplementation has not been studied but may be beneficial. Long-term bone health and fracture risk unknown. If abnormalities are suspected, expert assessment is recommended.

• 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.

• Lactic acidosis/severe hepatomegaly: [US Boxed Warning]: Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with nucleoside analogs in combination with other antiretrovirals; use with caution in patients with risk factors for liver disease (risk may be increased with female gender, prolonged use, or obesity) although cases have occurred in patients with no known risk factors. Suspend treatment in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (transaminase elevation may/may not accompany hepatomegaly and steatosis).

• Osteomalacia and renal dysfunction: In patients taking tenofovir disoproxil fumarate, cases of osteomalacia associated with proximal renal tubulopathy with bone pain or extremity pain (which may contribute to fractures) have been reported; hypophosphatemia and osteomalacia secondary to proximal renal tubulopathy have also occurred in patients at risk for renal dysfunction who present with persistent or worsening bone or muscle symptoms. The risk of osteomalacia in patients taking tenofovir alafenamide is not known. In patients at risk for renal dysfunction, persistent or worsening bone or muscle symptoms should be evaluated for renal dysfunction, hypophosphatemia and osteomalacia.

• Pancreatitis: Pancreatitis has been reported with nucleoside analogues; use caution in patients at risk for or with a history of pancreatitis.

• Renal toxicity: May cause renal toxicity (acute renal failure and/or Fanconi syndrome); patients with impaired renal function and those with concurrent or recent nephrotoxic therapy (including NSAID use) are at an increased risk. In all patients calculate estimated creatinine clearance and measure urine glucose and urine protein prior to treatment initiation and during therapy; monitor serum phosphorus in patients with chronic kidney disease. Discontinue use in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome. Cobicistat component inhibits tubular creatinine secretion without affecting glomerular filtration; may cause modest declines in estimated renal function early in therapy (typically within two weeks of initiation) and is reversible upon discontinuation. Closely monitor patients with a confirmed >0.4 mg/dL increase of serum creatinine from baseline for renal safety.

Disease-related concerns:

• Chronic hepatitis B: [US Boxed Warning]: Severe acute exacerbations of hepatitis B have been reported in patients who are coinfected with HIV-1 and HBV and have discontinued products containing emtricitabine and/or tenofovir disoproxil fumarate (TDF), and may occur with elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide. All patients with HIV should be tested for HBV prior to initiation of treatment. This combination is not approved for the treatment of chronic HBV infection and safety/efficacy in HBV/HIV-1 coinfected patients has not been established. In some HBV patients treated with emtricitabine, HBV exacerbations have been associated with liver decompensation and liver failure. Monitor clinical and laboratory hepatic function closely for several months following discontinuation. If appropriate, initiation of HBV therapy may be needed.

• Hepatic impairment: Use is not recommended in severe hepatic impairment (Child-Pugh Class C); has not been studied in this population.

• Renal impairment: May cause renal toxicity (acute renal failure and/or Fanconi syndrome); patients with impaired renal function and those with concurrent or recent nephrotoxic therapy (including NSAID use) are at an increased risk; monitor serum phosphorus in patients with chronic kidney disease. Do not initiate in patients with CrCl <30 mL/minute; continued use in patients with CrCl that declines to <30 mL/minute is not recommended.

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.

Other warnings/precautions:

• Appropriate use: Avoid concurrent use with adefovir-, lamivudine-, or ritonavir-containing products or other cobicistat-, elvitegravir-, emtricitabine-, and/or tenofovir-disoproxil fumarate-containing products. Not recommended for concomitant use with other antiretroviral (ARV) drugs.

Monitoring Parameters

CBC with differential, reticulocyte count, creatine kinase, CD4 count, HIV RNA plasma levels, serum phosphorus; serum creatinine, BUN, urine glucose and urine protein prior to initiation and as clinically indicated during therapy, hepatic function tests, bone density (patients with a history of bone fracture or have risk factors for bone loss); testing for HBV is recommended prior to the initiation of antiretroviral therapy; weight (children and adolescents). Reevaluation of serum creatinine, BUN, and serum phosphorus in patients with bone pain, extremity pain, fractures or muscle pain.

Patients with HIV and HBV coinfection should be monitored for several months following combination product discontinuation.

Pregnancy Risk Factor

B

Pregnancy Considerations

Animal reproduction studies have not been conducted with this combination. Refer to individual monographs.

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 headache, nausea, loss of strength and energy, or diarrhea. Have patient report immediately to prescriber signs of too much lactic acid in the blood (lactic acidosis; fast breathing, fast heartbeat, abnormal heartbeat, vomiting, drowsiness, shortness of breath, feeling very tired or weak, severe dizziness, feeling cold, or muscle pain or cramps), signs of kidney problems (urinary retention, blood in urine, change in amount of urine passed, weight gain), signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), bone pain, change in body fat, or signs of infection (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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