Raltegravir, sold under the brand name Isentress, is an antiretroviral medication used, together with other medication, to treat HIV/AIDS. It may also be used, as part of post exposure prophylaxis, to prevent HIV infection following potential exposure. It is taken by mouth. Raltegravir was approved for medical use in the United States in 2007. It is on the World Health Organization's List of Essential Medicines. Lamivudine/raltegravir, a combination with lamivudine, is also available.