When given with lopinavir/ritonavir, the dose of Descovy for HIV-1 treatment is 200/10 mg once daily. Co-administration of Descovy with medicinal products that inhibit P-gp and BCRP activity (e.g., ritonavir) are expected to increase the absorption and plasma concentration of tenofovir alafenamide. Coadministration of lopinavir/ritonavir (800/200 mg once daily) and tenofovir alafenamide (10 mg once daily) increased tenofovir alafenamide AUC and Cmax by 47% and 119%, with no change in lopinavir AUC, Cmax and Cmin.

Based on drug interaction studies conducted with the components of Descovy, no clinically significant drug interactions have been either observed or are expected when Descovy is combined with lopinavir/ritonavir. Coadministration of lopinavir/ritonavir (800/200 mg once daily) and tenofovir alafenamide (10 mg once daily) was studied in 10 subjects. Tenofovir alafenamide Cmax and AUC increased by 119% and 47%; there was no change in lopinavir Cmax and AUC, but Cmin decreased by 2%.

Coadministration of lopinavir/ritonavir (800/200 mg, once daily) with emtricitabine/tenofovir alafenamide (200/10 mg, once daily) was studied in 10 healthy volunteers in a crossover study. Tenofovir alafenamide AUC and Cmax increased by 47% and 119%, respectively. Tenofovir AUC and Cmax increased by 322% and 275%, respectively. Lopinavir pharmacokinetic parameters were similar to historical controls. The authors hypothesise that the increase in tenofovir alafenamide and tenofovir exposures are due to intestinal inhibition of P-gp and/or BCRP by ritonavir. Coadministration of lopinavir/ritonavir with tenofovir alafenamide is supported by tenofovir alafenamide safety data.