Tenofovir is used in combination with other antiviral medications to treat human immunodeficiency virus (HIV) in patients with acquired immunodeficiency syndrome (AIDS). Tenofovir is in a class of antiviral medications called reverse transcriptase inhibitors. It works by slowing the spread of HIV in the body. Tenofovir is not a cure and may not decrease the number of HIV-related illnesses. Tenofovir does not prevent the spread of HIV to other people.