Zidovudine

Zidovudine (INN) or azidothymidine (AZT) (also called ZDV) is a nucleoside analog reverse-transcriptase inhibitor (NRTI), a type of antiretroviral drug used for the first clinically proven successful treatment of HIV/AIDS infectiousness. It is a therapeutic analog of thymidine that targets HIV exclusively. It remains in widespread use today and is recognized by the Centers for Disease Control as one of the most effective drugs in medical history.

AZT is the first U.S. government-approved treatment for HIV therapy, prescribed under the names Retrovir and Retrovis. AZT was the first breakthrough in AIDS therapy, significantly reducing the replication of the virus in patients and leading to clinical and immunologic improvements. It can also be used to prevent HIV transmission, such as from mother to child during the period of birth or after a needle stick. Used by itself in HIV-infected patients, AZT safely slows HIV replication in patients, but generally does not stop it entirely. This may allow HIV to become AZT-resistant over time, and for this reason AZT is usually used in conjunction with the other anti-HIV drugs in combination therapy called highly active antiretroviral therapy (HAART).

To simplify its use in combination, AZT is included in Combivir and Trizivir, among others. Zidovudine is mandated in the "Essential Drugs List" of the World Health Organization, which is a list of minimum medicinal needs for a basic health care system.