Tenofovir AIDS drug molecule. Computer model of a molecule of the AIDS (acquired immune deficiency syndrome) drug tenofovir. Atoms are represented as spheres and are colour-coded; carbon (green), hydrogen (white), oxygen (red), nitrogen (dark blue) and phosphorous (yellow). Tenofovir belongs to a class of drugs known as nucleoside reverse transcriptase inhibitors (NRTIs). It slows the spread of HIV (human immunodeficiency virus) in the body by inhibiting reverse transcriptase, the enzyme that converts HIV RNA (ribonucleic acid) into viral DNA (deoxyribonucleic acid) that can be incorporated into human cells. Tenofovir is used in combination with other medications.