Raltegravir is primarily used in the treatment of HIV infection. It works by inhibiting the integrase enzyme, which is essential for the replication of the HIV virus. By blocking this enzyme, it prevents the virus from integrating its genetic material into the DNA of human cells, thereby slowing down the progression of the disease. This medication is often prescribed as part of a combination therapy, known as antiretroviral therapy (ART), to enhance its effectiveness and reduce the risk of developing drug resistance. It is particularly beneficial for patients who have developed resistance to other classes of antiretroviral drugs. Raltegravir has been shown to significantly reduce viral load and improve immune system function in HIV-positive individuals, making it a crucial component in the management of HIV/AIDS.