No Interaction Expected
Emtricitabine/Tenofovir-DF (FTC/TDF, PrEP)
Quality of Evidence: Very Low
Coadministration of emtricitabine/tenofovir-DF and isoniazid alone has not been studied but based on metabolism and clearance, a clinically significant interaction is unlikely. Isoniazid is acetylated in the liver to form acetylisoniazid which is then hydrolysed to isonicotinic acid and acetylhydrazine. Coadministration of TB treatment containing isoniazid (with rifampicin, ethambutol and pyrazinamide) and emtricitabine/tenofovir-DF (with efavirenz) decreased isoniazid Cmax by 5%. Emtricitabine AUC and Cmin increased by 5% and 26% and Cmax decreased by 3%. Tenofovir AUC and Cmin increased by 13% and 9% and Cmax decreased by 2%.