Based on theoretical considerations this anticonvulsant is expected to decrease darunavir and/or cobicistat plasma concentrations (CYP3A induction). Co-administration of darunavir/cobicistat and these anticonvulsants is contraindicated due to the potential for loss of therapeutic effect.

Coadministration is expected to decrease concentrations of darunavir and cobicistat. Coadministration is contraindicated due to the potential for reduced plasma concentrations of darunavir, which may result in loss of therapeutic effect and development of resistance.

The drug-drug interactions between antiretrovirals and carbamazepine or oxcarbazepine were evaluated in a clinical setting using therapeutic drug monitoring (TDM) trough concentrations collected from HIV+ patients treated concomitantly with carbamazepine or oxcarbazepine and antiretrovirals for at least 3 months. HIV-infected patients not concomitantly treated with antiepileptic drugs and who underwent TDM for antiretrovirals in the previous 2 years were considered as controls. Eleven HIV-positive patients prescribed carbamazepine (n=7) or oxcarbazepine (n=4) were identified. All the TDM evaluations for carbamazepine and oxcarbazepine were within the therapeutic ranges. TDM results of darunavir measured in these patients were comparable with values usually measured in the control group.