Co-administration is not recommended. The interaction has not been studied with any of the components of Biktarvy. Co-administration may decrease bictegravir and tenofovir alafenamide plasma concentrations due to induction of CYP3A, UGT1A1, and P-gp.

Coadministration may decrease concentrations of bictegravir and tenofovir alafenamide. Coadministration with alternative anticonvulsants should be considered.

A 54-year-old person with HIV (diagnosis in 2020) and a medical history of lower extremity neuropathy did not respond to amitriptyline, gabapentin, pregabalin and topical agents which led to the prescription of oxcarbazepine (300 mg twice daily). The patient reported taking a reduced dose of oxcarbazepine (150 mg twice daily or three time daily) due to somnolence. Remarkably, despite the inducing effect of oxcarbazepine, the patient remained virologically suppressed on bictegravir/tenofovir alafenamide/emtricitabine (50/50/200 mg once daily) with two documented bictegravir trough concentrations in the therapeutic range. This observation is likely explained by the lower dose of oxcarbazepine knowing that oxcarbazepine has a dose dependent inducing effect. Thus, the authors suggest that concomitant administration of bictegravir may be feasible with daily oxcarbazepine doses <600 mg. Additional TDM of bictegravir monitoring may be warranted in case of baseline poor viral load suppression or if oxcarbazepine precedes antiretroviral initiation.