Protease inhibitors are synthetic drugs that inhibit the action of HIV-1 protease, an enzyme that cleaves two precursor proteins into smaller fragments. These fragments are needed for viral growth, infectivity and replication. Protease inhibitors bind to the active site of the protease enzyme and prevent the maturation of the newly produced virions so that they remain non-infectious.
Protease inhibitors are used in the treatment of human immunodeficiency virus (HIV infection) and acquired immune deficiency syndrome (AIDS).