Atazanavir and cobicistat

Coadministration of EVOTAZ can alter the concentration of other drugs and other drugs may alter the concentration of EVOTAZ, which may result in known or potentially significant drug interactions. The potential drug-drug interactions must be considered prior to and during therapy. (4 , 7 , 12.3)

7.1 Potential for EVOTAZ to Affect Other Drugs Atazanavir is an inhibitor of CYP3A and UGT1A1 and a weak inhibitor of CYP2C8. Cobicistat is an inhibitor of CYP3A and CYP2D6. The transporters that cobicistat inhibits include P-glycoprotein (P-gp), BCRP, OATP1B1 and OATP1B3. Coadministration of EVOTAZ with drugs highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events is contraindicated [see Contraindications (4) ] .

Coadministration of EVOTAZ and drugs primarily metabolized by CYP3A, UGT1A1 and/or CYP2D6 or drugs that are substrates of P-gp, BCRP, OATP1B1 and/or OATP1B3 may result in increased plasma concentrations of the other drug that could increase or prolong its therapeutic effects and adverse reactions which may require dose adjustments and/or additional monitoring as shown in Table 5. Use of EVOTAZ is not recommended when coadministered with drugs highly dependent on CYP2C8 for clearance with narrow therapeutic indices (e.g., paclitaxel, repaglinide) [see Clinical Pharmacology (12.3; Table 7) ] .

7.2 Potential for Other Drugs to Affect EVOTAZ Atazanavir and cobicistat are CYP3A4 substrates; therefore, drugs that induce CYP3A4 may decrease atazanavir and cobicistat plasma concentrations and reduce the therapeutic effect of EVOTAZ, leading to development of resistance to atazanavir (see Table 5). Cobicistat is also metabolized by CYP2D6 to a minor extent. Coadministration of EVOTAZ with other drugs that inhibit CYP3A4 may increase the plasma concentrations of cobicistat and atazanavir (see Table 5). Atazanavir solubility decreases as pH increases.

Reduced plasma concentrations of atazanavir are expected if proton-pump inhibitors, antacids, buffered medications, or H 2 -receptor antagonists are administered with EVOTAZ (see Table 5) [see Dosage and Administration (2.2) ] .

7.3 Established and Other Potentially Significant Drug Interactions Table 5 provides dosing recommendations as a result of drug interactions with the components of EVOTAZ. These recommendations are based either on observed drug interactions in studies of cobicistat, atazanavir, or atazanavir coadministered with ritonavir or predicted drug interactions based on the expected magnitude of interaction and potential for serious events or loss of therapeutic effect of EVOTAZ [see Contraindications (4) , Warnings and Precautions (5.8) , and Clinical Pharmacology (12.3) ] .

Table 5: Established and Other Potentially Significant Drug Interactions with EVOTAZ: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies a or Predicted Interactions Concomitant Drug Class: Specific Drugs Effect b on Concentration Clinical Comment a For magnitude of interactions see Clinical Pharmacology (12.3; Table 7) . b ↑ = Increase, ↓ = Decrease, ↔ = No change.

HIV Antiretroviral Agents: Nucleoside and Nucleotide Reverse Transcriptase Inhibitors (NRTIs and NtRTIs) didanosine buffered formulations enteric-coated (EC) capsules ↓ atazanavir ↓ didanosine It is recommended that EVOTAZ be given with food 2 hours before or 1 hour after didanosine buffered formulations. Simultaneous administration of didanosine EC and atazanavir with food results in a decrease in didanosine exposure. Thus, EVOTAZ and didanosine EC should be administered at different times. tenofovir disoproxil fumarate ↓ atazanavir ↑ tenofovir Patients receiving EVOTAZ and tenofovir should be monitored for tenofovir-associated adverse reactions [see Warnings and Precautions (5.4) ] .

HIV Antiretroviral Agents: Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs) nevirapine ↓ atazanavir ↑ nevirapine Coadministration of EVOTAZ with nevirapine is contraindicated due to potential for loss of atazanavir therapeutic effect and development of resistance, and potential for nevirapine-associated adverse reactions [see Contraindications (4) ] . efavirenz ↓ atazanavir ↓ cobicistat ↔ efavirenz Coadministration of EVOTAZ with efavirenz is not recommended because it may result in a loss of therapeutic effect and development of resistance to atazanavir.

etravirine ↓ atazanavir ↓ cobicistat Coadministration of EVOTAZ with etravirine is not recommended because it may result in the loss of therapeutic effect and development of resistance to atazanavir. HIV Antiretroviral Agents: CCR5 Antagonist maraviroc ↑ maraviroc When coadministering maraviroc and EVOTAZ, patients should receive maraviroc 150 mg twice daily. HIV Antiretroviral Agents: Protease Inhibitor indinavir Coadministration with indinavir is contraindicated [see Contraindications (4) ] . Both atazanavir and indinavir are associated with indirect (unconjugated) hyperbilirubinemia.

ritonavir or products containing ritonavir ↑ atazanavir Coadministration of EVOTAZ and ritonavir or ritonavir-containing regimens is not recommended due to similar effects of cobicistat and ritonavir on CYP3A [see Warnings and Precautions (5.9) ] . Hepatitis C Antiviral Agents sofosbuvir/velpatasvir/ voxilaprevir ↑ voxilaprevir Coadministration with EVOTAZ is not recommended. Other Agents Alpha 1-adrenoreceptor antagonist: alfuzosin ↑ alfuzosin Coadministration of EVOTAZ with alfuzosin is contraindicated due to the potential for increased alfuzosin concentrations, which can result in hypotension [see Contraindications (4) ] .

Antacids and buffered medications (please also see H 2 -receptor antagonists and proton-pump inhibitors below) ↓ atazanavir With concomitant use, administer a minimum of 2 hours apart. Antianginal: ranolazine ↑ ranolazine Coadministration of EVOTAZ with ranolazine is contraindicated due to the potential for serious and/or life-threatening reactions [see Contraindications (4) ] . Antiarrhythmics: dronedarone ↑ dronedarone Coadministration of EVOTAZ with dronedarone is contraindicated due to potential for serious and/or life-threatening reactions such as cardiac arrhythmias [see Contraindications (4) ] .

amiodarone, quinidine lidocaine (systemic), disopyramide, flecainide mexiletine, propafenone digoxin ↑ other antiarrhythmics ↑ digoxin Clinical monitoring is recommended upon coadministration with antiarrhythmics. When coadministering EVOTAZ with digoxin, titrate the digoxin dose and monitor digoxin concentrations. Antibacterials (macrolide or ketolide antibiotics): clarithromycin erythromycin telithromycin ↑ atazanavir ↑ cobicistat ↑ clarithromycin ↑ erythromycin ↑ telithromycin Consider alternative antibiotics.

Anticancer Agents: irinotecan ↑ irinotecan Coadministration of EVOTAZ with irinotecan is contraindicated due to potential for increased irinotecan toxicity [see Contraindications (4) ] . (e.g., dasatinib, nilotinib, vinblastine, vincristine) ↑ other anticancer agents A decrease in the dosage or an adjustment of the dosing interval of dasatinib or nilotinib may be necessary upon coadministration with EVOTAZ. Consult the dasatinib and nilotinib full prescribing information for dosing instructions. For vincristine and vinblastine, monitor for hematologic or gastrointestinal side effects.

Anticoagulants: Direct-acting oral anticoagulants (DOACs) apixaban ↑ apixaban Due to potentially increased bleeding risk, dosing recommendations for coadministration of apixaban with EVOTAZ depends on the apixaban dose. Refer to apixaban dosing instructions for coadministration with strong CYP3A4 and P-gp inhibitors in apixaban prescribing information. rivaroxaban ↑ rivaroxaban Coadministration of EVOTAZ and rivaroxaban is not recommended because it may lead to increased bleeding risk.

betrixaban dabigatran etexilate edoxaban ↑ betrixaban ↑ dabigatran ↑ edoxaban Due to potentially increased bleeding risk, dosing recommendations for coadministration of betrixaban, dabigatran, or edoxaban with a P-gp inhibitor such as EVOTAZ depends on DOAC indication and renal function. Refer to DOAC dosing instructions for coadministration with P-gp inhibitors in DOAC prescribing information. warfarin warfarin: effect unknown Monitor the International Normalized Ratio (INR) when EVOTAZ is coadministered with warfarin.

Anticonvulsants: carbamazepine, phenobarbital, phenytoin Anticonvulsants with CYP3A induction effects that are NOT contraindicated (e.g., eslicarbazepine, oxcarbazepine) ↓ atazanavir ↓ cobicistat ↓ atazanavir ↓ cobicistat Coadministration of EVOTAZ with carbamazepine, phenobarbital, or phenytoin is contraindicated due to potential for loss of therapeutic effect and development of resistance [see Contraindications (4) ] . Consider alternative anticonvulsant or antiretroviral therapy to avoid potential changes in exposures. If coadministration is necessary, monitor for lack or loss of virologic…

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to EVOTAZ during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary EVOTAZ is not recommended for use during pregnancy and should not be initiated in pregnant individuals [see Dosage and Administration (2.5) ] ; use of an alternative regimen is recommended for individuals who become pregnant during therapy with EVOTAZ.

Pharmacokinetic data from studies conducted in pregnant individuals receiving cobicistat showed substantially lower exposures during the second and third trimesters, and consequently also for the coadministered antiretroviral agent. Consult the full prescribing information for cobicistat for additional information. Pharmacokinetic data from the evaluation of atazanavir and cobicistat in a limited number of pregnant individuals showed a similar trend in lower exposures of the antiretroviral component, atazanavir. Prospective pregnancy data from the APR are not sufficient to adequately assess the risk of birth defects or miscarriage.

Atazanavir use during pregnancy has been evaluated in a limited number of individuals. Available data from the APR show no increase in the risk of overall major birth defects for atazanavir compared with the background rate for major birth defects of 2.7% in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP) (see Data) . The rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15−20%.

In animal reproduction studies, no evidence of adverse developmental outcomes was observed following oral administration of the components of EVOTAZ (atazanavir or cobicistat) to pregnant rats and rabbits (see Data) . During organogenesis in the rat and rabbit, atazanavir exposures (AUC) were similar to those observed at the human clinical dose (300 mg/day atazanavir boosted with 100 mg/day ritonavir), while exposures were up to 1.4 (rats) and 3.3 (rabbits) times human exposures at the maximal recommended human dose (MRHD) of 150 mg (see Data) . Clinical Considerations EVOTAZ is not recommended for use during pregnancy and should not be initiated in pregnant individuals.

An alternative regimen is recommended for individuals who become pregnant during therapy with EVOTAZ (see Risk Summary) . Maternal Adverse Reactions Atazanavir Reports of lactic…