Raltegravir: the first in a new class of integrase inhibitors for the treatment of HIV.

Raltegravir (formerly known as MK-0518; Isentress) is the first in a new class of integrase inhibitors approved for the use in treatment-experienced adult patients who have evidence of viral replication and HIV strains resistant to multiple antiretroviral agents. It is dosed twice daily with or without food. Raltegravir is a novel antiretroviral that has been shown to be well tolerated. It has demonstrated potent efficacy in the virologic suppression of HIV-1 RNA levels up to 48 weeks in two controlled studies that were conducted in clinically advanced, three-class antiretroviral, treatment-experienced adults.