Tenofovir/emtricitabine HIV drug. Box containing oral tablets of the combination drug tenofovir/emtricitabine, used to treat AIDS (acquired immune deficiency syndrome). This drug is a nucleoside reverse transcriptase inhibitor (NRTI), used as a part of antiretroviral therapy in the treatment of HIV (human immunodeficiency virus). It slows the spread of HIV in the body by inhibiting reverse transcriptase, the enzyme that converts HIV RNA (ribonucleic acid) into viral DNA (deoxyribonucleic acid) which can be incorporated into human cells. If antiretroviral drugs are used alone HIV rapidly develops resistance to them. Therefore, it is recommended that therapy consists of a combination of three or more antiretrovirals drugs.