Enfuvirtide

It was the first of a new class of antiretroviral drugs known as entry inhibitors. Enfuvirtide is a fusion inhibitor. For HIV to gain entry into the host cell, it must fuse its membrane with that of the host cell. This is accomplished by changes in the conformation of the viral transmembrane glycoprotein gp41, which occurs when HIV binds to the host cell surface. Enfuvirtide is a 36-amino-acid peptide that binds to gp41, preventing the conformational change. Enfuvirtide, in combination with other antiretroviral agents, is approved for therapy of treatment-experienced patients with evidence of viral replication despite ongoing antiretroviral drug therapy. As a peptide it must be given subcutaneously. Most of the adverse effects are related to the injection, including pain, erythema, induration, and nodules, which occur in almost all patients. However, only 3 percent discontinue treatment because of them. Enfuvirtide must be reconstituted prior to administration. It is an expensive medication.Enfuvirtide preventing the conformational changes required for the fusion of the viral and cellular membranes. There is no cross-resistance with other anti-HIV drugs, but resistance may occur via mutations in the env gene. Enfuvirtide is administered subcutaneously in combination with other anti-HIV agents in previously drug-treated patients with persistent HIV-1 replication despite ongoing therapy. Its metabolism via hydrolysis does not involve the cytochrome P450 system. Injection site reactions and hypersensitivity may occur. An increased incidence of bacterial pneumonia has been reported.