Coadministration has not been studied, but dolutegravir may decrease due to induction of UGT1A1 and CYP3A enzymes. A similar reduction in exposure as observed with carbamazepine is expected. Since the recommended dose of dolutegravir is 50 mg twice daily when co-administered with these metabolic inducers, Triumeq is not recommended for patients taking oxcarbazepine.

Coadministration may decrease dolutegravir concentrations. Avoid coadministration with Triumeq because there are insufficient data to make dosing recommendations.

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. Trough concentrations for dolutegravir were ~83% lower when compared with HIV-infected patients not treated with antiepileptic drugs (191 ± 78 versus 1096 ± 510 ng/mL). Co-administration of carbamazepine or oxcarbazepine with dolutegravir should be avoided owing to the potential risk of virological failure; the adoption of TDM is strongly advisable, eventually combining with increased antiretroviral doses.