Trizivir is a combination antiretroviral medication used in the treatment of HIV/AIDS. It contains three active ingredients: abacavir, lamivudine, and zidovudine. These components belong to a class of drugs known as nucleoside reverse transcriptase inhibitors (NRTIs), which work by interfering with the replication process of the human immunodeficiency virus (HIV). By doing so, Trizivir helps to lower the amount of HIV in the body, thereby improving the immune system function and reducing the risk of HIV-related illnesses. It is important for patients to be tested for a genetic marker called HLA-B*5701 before starting treatment with Trizivir, as those with this marker may have a higher risk of experiencing a hypersensitivity reaction to abacavir, one of the components of Trizivir. This medication is used as part of combination therapy, meaning it should be used in conjunction with other antiretroviral medications for the most effective management of HIV.