Clinical data
Trade namesRetrovir, others
License data
  • AU: B3
  • US: C (Risk not ruled out) (AZT)
Routes of
By mouth, IV, rectal suppository
ATC code
Legal status
Legal status
  • In general: ℞ (Prescription only)
Pharmacokinetic data
BioavailabilityComplete absorption, following first-pass metabolism systemic availability 75% (range 52 to 75%)
Protein binding30 to 38%
half-life0.5 to 3 hours
Excretionkidney and biliary
30516-87-1 ☑Y
DB00495 ☑Y
32555 ☑Y
D00413 ☑Y
CHEBI:10110 ☒N
ChEMBL129 ☑Y
DTXSID8020127 Edit this at Wikidata
100.152.492 Edit this at Wikidata
Chemical and physical data
Molar mass267.242 g/mol g·mol−1
3D model (Interactive image
 ☒N☑Y (verify)

Zidovudine (ZDV), also known as azidothymidine (AZT), is an antiretroviral medication used to prevent and treat HIV/AIDS.[2] It is generally recommended for use with other antiretrovirals.[2] It may be used to prevent mother-to-child spread during birth or after a needlestick injury or other potential exposure.[2] It is sold both by itself and together as lamivudine/zidovudine and abacavir/lamivudine/zidovudine.[2] It can be used by mouth or by slow injection into a vein.[2]

Common side effects include headaches, fever, and nausea.[2] Serious side effects include liver problems, muscle damage, and high blood lactate levels.[2] It is commonly used in pregnancy and appears to be safe for the baby.[2] ZDV is of the nucleoside analog reverse-transcriptase inhibitor (NRTI) class.[2] It works by inhibiting the enzyme reverse transcriptase that HIV uses to make DNA and therefore decreases replication of the virus.[2]

Zidovudine was first described in 1964.[3] It was approved in the United States in 1987 and was the first treatment for HIV.[2][4] It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[5] It is available as a generic medication.[2] The wholesale cost in the developing world is US$5.10 to $25.60 per month.[6] As of 2015, the cost for a typical month of medication in the United States was more than $200.[7]

Medical uses

HIV treatment

AZT is usually dosed twice a day in combination with other antiretroviral therapies. This approach is referred to as Highly Active Antiretroviral Therapy (HAART) and is used to prevent the likelihood of HIV resistance.[8][9]

HIV prevention

AZT has been used for post-exposure prophylaxis (PEP) in combination with another antiretroviral drug called lamivudine. Together they work to substantially reduce the risk of HIV infection following the first single exposure to the virus.[10] More recently, AZT has been replaced by other antiretrovirals such as tenofovir to provide PEP.[11]

AZT is now a principal part of the clinical pathway for both pre-exposure prophylaxis and post-exposure treatment of mother-to-child transmission of HIV during pregnancy, labor, and delivery and has been proven to be integral to uninfected siblings' perinatal and neonatal development.[12][13] Without AZT, as many as 10 to 15% of fetuses with HIV-infected mothers will themselves become infected.[14] AZT has been shown to reduce this risk to as little as 8% when given in a three-part regimen post-conception, delivery, and six weeks post-delivery. Consistent and proactive precautionary measures, such as the rigorous use of antiretroviral medications, cesarean section, face masks, heavy-duty rubber gloves, clinically segregated disposable diapers, and avoidance of mouth contact will further reduce child-attendant transmission of HIV to as little as 1–2%.[15][16][17]

During 1994 to 1999, AZT was the primary form of prevention of mother-to-child HIV transmission. AZT prophylaxis prevented more than 1000 parental and infant deaths from AIDS in the United States.[18] In the US at this time, the accepted standard of care for HIV-positive mothers was known as the 076 regimen and involved 5 daily doses of AZT from the second trimester onwards, as well as AZT intravenously administered during labour.[19] As this treatment was lengthy and expensive, it was deemed unfeasible in the Global South, where mother-to-child transmission was a significant problem. A number of studies were initiated in the late 1990s that sought to test the efficacy of a shorter, simpler regimen for use in ‘resource-poor’ countries.[20] This AZT short course was an inferior standard of care and would have been considered malpractice if trialed in the US; however, it was nonetheless a treatment that would improve the care and survival of impoverished subjects.[20]

Other Languages
Afrikaans: Sidovudien
العربية: زيدوفودين
تۆرکجه: زیدوودین
català: Zidovudina
Cymraeg: Sidofwdin
dansk: Zidovudin
Deutsch: Zidovudin
español: Zidovudina
Esperanto: Zidovudino
فارسی: زیدوودین
français: Zidovudine
한국어: 지도부딘
հայերեն: Զիդովուդին
Bahasa Indonesia: Zidovudin
italiano: AZT
magyar: Zidovudin
монгол: Зидовудин
日本語: ジドブジン
português: Zidovudina
русский: Зидовудин
slovenščina: Zidovudin
српски / srpski: Zidovudin
srpskohrvatski / српскохрватски: Zidovudin
svenska: AZT
తెలుగు: జిడోవుడిన్
українська: АЗТ
Tiếng Việt: Zidovudine
中文: 齐多夫定