Coadministration of dolutegravir (50 mg once daily) and tenofovir-DF (300 mg once daily) was studied in 15 HIV-negative subjects. The pharmacokinetic parameters of tenofovir and dolutegravir when coadministered were comparable to those when given alone, demonstrating no significant drug interaction. Dolutegravir AUC increased by 1%, but Cmax and Ctrough decreased by 3% and 8%, respectively. Tenofovir AUC, Cmax and Ctrough increased by 12%, 9% and 19%, respectively.