Zidovudine
A thymidine analog NRTI used with other antiretrovirals for HIV and to prevent HIV passing from mother to baby.
Also called AZT (abbreviation (azidothymidine)) or ZDV (abbreviation).
Drug card
- How it works
- Ending the viral DNA chain as false nucleotides for reverse transcriptase
- Used for
- HIV-1 infection, with other antiretrovirals
- Preventing HIV passing from mother to baby
- Known for
- Anemia, sometimes severe
- Neutropenia and other low blood counts
- Its name
- -vudine means a nucleoside antiviral (zidovudine type)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does zidovudine work?
A thymidine analog that cell kinases turn into zidovudine triphosphate, which HIV reverse transcriptase builds into viral DNA, ending the chain. It weakly inhibits human DNA polymerases alpha and gamma, the mitochondrial enzyme, and its main toxicity falls on the bone marrow.
Like other nucleoside reverse transcriptase inhibitors: NRTIs are nucleoside or nucleotide look-alikes. Cell kinases phosphorylate them to their active forms, which compete with natural nucleotides at the active site of HIV reverse transcriptase. Once built into the viral DNA copy they end the chain, so HIV cannot make DNA from its RNA. Some also block the hepatitis B polymerase, and they weakly inhibit human DNA polymerases.
Uses
What is zidovudine used for?
- HIV-1 infection, with other antiretrovirals
- Preventing HIV passing from mother to baby
Side effects
Side effects of zidovudine
- Anemia, sometimes severeKnown forSerious
- Neutropenia and other low blood countsKnown forSerious
- Headache
- Nausea and vomiting
- Loss of appetite
- Weakness and malaise
- Myopathy with long-term useSerious
- Lactic acidosis with fatty, enlarged liverSerious
- Fat loss from face and limbs (lipoatrophy)
- Darkening of skin and nails
- CardiomyopathySerious
- PancreatitisSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Check blood counts often, especially in advanced HIV or poor bone marrow reserve.
- Avoid with stavudine or doxorubicin (antagonism) and with ribavirin, which worsens anemia.
- Other marrow-suppressing drugs, such as ganciclovir or interferon alfa, add to its blood toxicity.
- HIV with hepatitis C on interferon: watch for liver decompensation.
Good to know: Its boxed warnings for marrow toxicity and myopathy set it apart from tenofovir and lamivudine.
Remember it
A way to remember it
NRTIs are fake bricks: the wall of viral DNA stops where they are laid.
Reverse transcriptase picks up the false nucleotide and builds it into the DNA copy of HIV's RNA, and no further bricks can be added: chain termination.
Written for biofideX
Its name
-vudine means nucleoside antiviral (zidovudine type)
Zidovudine and lamivudine block HIV reverse transcriptase, and lamivudine also treats hepatitis B. WHO files -vudine under -uridine.
- Every drug name stem
Its class
Nucleoside reverse transcriptase inhibitors
Other nucleoside reverse transcriptase inhibitors with a card:
Easily mixed up with non-nucleoside reverse transcriptase inhibitors and antiherpes nucleoside analogues.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antivirals
Zidovudine is one of 10 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
Start Practicing