Zidovudine: The first HIV treatment that changed the course of a global epidemic

Health · Published 3 October 2026 Swipe more like this →

In short: Zidovudine, also known as AZT, was the first medication approved to treat HIV. While it is no longer the standard for adult treatment, its role in preventing mother-to-child transmission remains a landmark in medical history. Understanding its complex side effects and mechanism is essential for grasping modern HIV care.

First described in 1964 and approved by the FDA in 1987, Zidovudine (Retrovir) marked a turning point as the first antiretroviral medication for HIV/AIDS. As a nucleoside reverse transcriptase inhibitor (NRTI), it functions by blocking the enzyme HIV requires to replicate its genetic material. During the 1990s, it became the primary tool for preventing perinatal HIV transmission. The landmark 076 regimen, which involved multiple daily doses during pregnancy and intravenous administration during labor, significantly reduced infant infection rates. This intervention prevented over 1,000 deaths in the United States between 1994 and 1999.

Despite its historical importance, Zidovudine is associated with serious, potentially life-threatening side effects. Patients may experience lactic acidosis, severe anemia, neutropenia, liver problems, and myopathy, particularly with long-term use. These complications are often linked to mitochondrial DNA depletion or interference with cellular processes. While modern lower-dose protocols have made these side effects less frequent, the drug is no longer commonly recommended for routine HIV treatment in adults and adolescents, having been largely replaced by more effective, once-daily regimens. It remains a specialized option for preventing transmission during pregnancy and treating specific conditions like multicentric Castleman's disease.

The clinical profile of Zidovudine is further complicated by drug-drug interactions. For instance, it acts as a substrate for UGT2B7, an enzyme that can be inhibited by other medications like fluconazole. Such interactions can alter how the body processes the drug, necessitating careful management. Furthermore, the International Agency for Research on Cancer has noted evidence of carcinogenicity in experimental animals, leading to its classification as possibly carcinogenic to humans. Today, while Zidovudine is rarely the first choice for HIV management, its legacy as a pioneer in antiretroviral therapy and its continued utility in specific perinatal contexts ensure it remains a significant subject in pharmacology and public health history.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• How a chemical derivative of adenine became a cornerstone of modern HIV treatment
• How antiretroviral drugs disrupt the HIV life cycle
• Undetectable HIV treatment blocks sexual transmission
• How medical technology transformed HIV from a terminal diagnosis into a manageable condition
• How David Ho transformed HIV from a terminal diagnosis into a manageable chronic condition
• Why two doses of the chickenpox vaccine are better than one for lasting protection
• Why a typhoid vaccine is essential for travelers visiting high-risk regions globally
• Topical medication: Why applying drugs directly to the body is more than skin deep
• Tigecycline: A powerful antibiotic that fights resistant bacteria but carries a hidden risk
• The diamond-shaped remedy: tracing the evolution of the modern throat lozenge
• Are your medications causing more harm than good? Understanding the reality of adverse effects.
• How a 1975 discovery became the world's most versatile weapon against parasitic worms

More in Drugs and medication · More in Health · Latest · A–Z · All topics