Raltegravir is an integrase inhibitor, the first of the class of antiviral agents active against the human immunodeficiency virus (HIV) that targets the viral integrase. Raltegravir is used in combination with other antiretroviral agents in the treatment of HIV infection. Raltegravir has not been linked convincingly to serum aminotransferase elevations during therapy or to episodes of acute, clinically apparent liver injury.