Darunavir and cobicistat are both inhibitors and substrates of the cytochrome P450 3A (CYP3A) isoform. PREZCOBIX® should not be co-administered with medicinal products that are highly dependent on CYP3A for clearance and for which increased plasma concentrations are associated with serious and/or life-threatening events (narrow therapeutic index). In addition, co-administration of PREZCOBIX® with CYP3A inducers may lead to lower exposures of darunavir and cobicistat, and potential loss of efficacy of darunavir and possible resistance.
Examples of drugs that are contraindicated for co-administration with PREZCOBIX® are: alfuzosin, carbamazepine, colchicine (in patients with renal and/or hepatic impairment), dihydroergotamine, dronedarone, elbasvir/grazoprevir, ergotamine, ivabradine, lomitapide, lovastatin, lurasidone, methylergonovine, oral midazolam, naloxegol, phenobarbital, phenytoin, pimozide, ranolazine, rifampin, St. John’s wort (Hypericum perforatum), sildenafil for pulmonary arterial hypertension, simvastatin, and triazolam.