Final answer:
AZT, or azidothymidine, was one of the earliest drugs used to treat AIDS, approved in 1987. It functions by inhibiting the HIV's reverse transcriptase enzyme. Modern treatment now involves HAART, a combination of drugs targeting different stages of the HIV life-cycle.
Step-by-step explanation:
One of the earliest drugs used to treat AIDS was azidothymidine (AZT), also known as zidovudine or by the brand name Retrovir. Approved in 1987, AZT became a groundbreaking medication for the management of AIDS. It functions by interfering with the action of reverse transcriptase, an enzyme crucial for the replication of HIV. AZT mimics deoxythymidine triphosphate, a building block of DNA, but once incorporated into the viral DNA chain, it prevents further elongation due to the lack of a 3'OH group. This effectively halts the replication process of the virus.
Modern HIV treatment has evolved to include a combination of drugs known as HAART (Highly Active Antiretroviral Therapy), or simply anti-retroviral therapy (ART). This regimen typically includes multiple antiretroviral drugs, such as nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs), that act on different stages of the HIV life-cycle to prevent the virus from developing resistance. By reducing the viral load in the body, HAART can effectively increase the lifespan and quality of life for those with HIV, as well as decrease the risk of transmission.