Raltegravirinteractions

Coadministration of ISENTRESS or ISENTRESS HD and other drugs may alter the plasma concentration of raltegravir. The potential for drug-drug interactions must be considered prior to and during therapy. Coadministration of ISENTRESS or ISENTRESS HD with drugs that are strong inducers of UGT1A1, such as rifampin, may result in reduced plasma concentrations of raltegravir.

7.1 Effect of

Other Agents on the Pharmacokinetics of Raltegravir Raltegravir is not a substrate of cytochrome P450 (CYP) enzymes. Based on in vivo and in vitro studies, raltegravir is eliminated mainly by metabolism via a UGT1A1-mediated glucuronidation pathway. Coadministration of ISENTRESS with drugs that inhibit UGT1A1 may increase plasma levels of raltegravir and coadministration of ISENTRESS with drugs that induce UGT1A1, such as rifampin, may reduce plasma levels of raltegravir (see Table 11 ). Selected drug interactions are presented in Table 11. In some cases, recommendations differ for ISENTRESS versus ISENTRESS HD.

Table 11: Selected Drug Interactions in Adults Concomitant Drug Class: Drug Name Effect on Concentration of Raltegravir Clinical Comment for ISENTRESS Clinical Comment for ISENTRESS HD Metal-Containing Antacids Aluminum and/or magnesium-containing antacids ↓ Coadministration or staggered administration is not recommended. Calcium carbonate antacid ↓ No dose adjustment Co-administration is not recommended Other Agents Rifampin ↓ The recommended dosage is 800 mg twice daily during coadministration with rifampin. There are no data to guide co-administration of ISENTRESS with rifampin in patients below 18 years of age. Coadministration is not recommended. Tipranavir/ritonavir No dose adjustment Coadministration is not recommended Etravirine ↓ No dose adjustment Coadministration is not recommended. Strong inducers of drug metabolizing enzymes not mentioned above e.g., Carbamazepine Phenobarbital Phenytoin ↓↔ The impact of other strong inducers of drug metabolizing enzymes on raltegravir is unknown. Coadministration is not recommended.

7.2 Drugs without

Clinically Significant Interactions with ISENTRESS or ISENTRESS HD ISENTRESS In drug interaction studies performed using ISENTRESS film-coated tablets 400 mg twice daily dose, raltegravir did not have a clinically meaningful effect on the pharmacokinetics of the following: ethinyl estradiol/norgestimate, methadone, midazolam, lamivudine, tenofovir disoproxil fumarate, etravirine, darunavir/ritonavir, or boceprevir. Moreover, atazanavir, atazanavir/ritonavir, boceprevir, calcium carbonate antacids, darunavir/ritonavir, efavirenz, etravirine, omeprazole, or tipranavir/ritonavir did not have a clinically meaningful effect on the pharmacokinetics of 400 mg twice daily raltegravir. No dose adjustment is required when ISENTRESS 400 mg twice daily is coadministered with these drugs. There is no predicted pharmacokinetic drug interaction between ISENTRESS and tenofovir alafenamide. ISENTRESS HD In drug interaction studies, efavirenz did not have a clinically meaningful effect on the pharmacokinetics of ISENTRESS HD 1200 mg (2 × 600 mg) once daily. No dose adjustment is recommended when ISENTRESS HD 1200 mg once daily is coadministered with atazanavir, atazanavir/ritonavir, hormonal contraceptives, methadone, lamivudine, tenofovir disoproxil fumarate, darunavir/ritonavir, boceprevir, efavirenz and omeprazole. There is no predicted pharmacokinetic drug interaction between ISENTRESS HD and tenofovir alafenamide.