Abstract
Raltegravir, an inhibitor of the HIV-1 integrase enzyme, is the first available agent in a new class of antiretroviral drugs. Raltegravir has been studied extensively in clinical trials, and has been well tolerated and highly effective in both treatment-naïve and -experienced patients. Resistance to raltegravir is unusual given its recent availability, but resistance with identified viral mutation pathways in the integrase gene in patients receiving the drug does occur.