Tenofovir is a nucleotide analogue reverse transcriptase inhibitor (nRTI) that causes premature termination of DNA transcription. Tenofovir is an antiretroviral used for HIV treatment and prevention.
Tenofovir has a low oral bioavailability. Hence, it is available as a prodrug called tenofovir disoproxil fumarate. Once ingested, tenofovir disoproxil fumarate is hydrolyzed to tenofovir and phosphorylated. This is then incorporated into the viral DNA which leads to chain termination. Tenofovir is also effective against hepatitis B virus.