Efavirenz + tenofovir alafenamide

Efavirenz + tenofovir alafenamide is a hypothetical combination of two antiretroviral drugs used in the treatment of HIV-1 infection. Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that binds directly to reverse transcriptase, blocking RNA-dependent and DNA-dependent DNA polymerase activities by causing a disruption of the enzyme's catalytic site. Tenofovir alafenamide is a prodrug of tenofovir, which is an acyclic nucleotide analog reverse transcriptase inhibitor (NRTI). After intracellular conversion to its active metabolite, tenofovir diphosphate, it inhibits HIV-1 reverse transcription by competing with natural substrates and causing chain termination. Tenofovir alafenamide was developed to improve safety over earlier forms such as tenofovir disoproxil fumarate by reducing plasma concentrations and increasing intracellular delivery, thereby lowering risks for renal and bone toxicity[4][6]. Both agents are approved for use in combination regimens for HIV-1 infection; however, there are no widely available fixed-dose combinations containing only efavirenz and tenofovir alafenamide without other agents.