What medication is commonly used to treat HIV?

Raltegravir is an antiretroviral medication that is used as part of the combination therapy to treat HIV infection. It belongs to a class of drugs known as integrase inhibitors, which work by preventing the HIV virus from integrating its genetic material into the host's DNA. This mechanism is vital for controlling the replication of the virus and helping to maintain a lower viral load in patients.

Each of the other options also represents medications used in the treatment of HIV, but they belong to different classes or have different primary uses. Azidothymidine (also known as zidovudine or AZT) is a nucleoside reverse transcriptase inhibitor that was one of the first drugs approved for HIV treatment. Tenofovir is another nucleoside analog but is commonly part of several combination therapies as either tenofovir disoproxil fumarate or tenofovir alafenamide. Ritonavir is a protease inhibitor and is frequently used in lower doses as a booster for other antiretroviral medications. While all these medications play important roles in HIV therapy, raltegravir is specifically recognized for its effectiveness as an integrase inhibitor, making it a key option in modern HIV treatment regimens.