Zidovudine
Zidovudine is an antiretroviral medication classified as a nucleoside reverse transcriptase inhibitor (NRTI) used in the treatment of HIV infection. It works by inhibiting the reverse transcriptase enzyme, which is essential for the virus to replicate. This medication is typically used in combination with other antiretroviral drugs as part of combination therapy.
Zidovudine is an HIV antiretroviral drug that inhibits viral replication by blocking reverse transcriptase.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- J05AF01
- RxNorm
- 11413
- Generic
- Zidovudine
- Class
- atc-j05
- Brands
- Combivir, Retrovir, Trizivir
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- injection, tablet, solution, capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesterstandard dosing recommended
continue treatment if already taking zidovudine; consider benefits of HIV treatment versus potential risks
regular prenatal monitoring and HIV viral load tracking
Use with caution and monitor for adverse effects.
pregnancy
third trimesterstandard dosing recommended
recommended for prevention of mother-to-child transmission; IV zidovudine during labor recommended for women with viral load greater than 1000 copies/mL
viral load monitoring, CD4 count, liver function tests
lactation
not recommendeddiscontinue breastfeeding
HIV-positive mothers should not breastfeed regardless of antiretroviral therapy status to prevent transmission
no specific monitoring required
Use of this medication in this population requires careful consideration of risks and benefits.
pediatric_age
neonatesweight-based dosing; 2 mg/kg orally every 6 hours or 1.5 mg/kg IV every 6 hours
indicated for prevention of vertical transmission in HIV-exposed infants; start within 6-12 hours of birth
monitor hemoglobin and neutrophils regularly; liver function tests
pediatric_age
children 3 months and olderweight-based dosing; 180-240 mg/m² every 6 hours
approved for pediatric HIV treatment; can be used in combination with other antiretrovirals
regular CBC monitoring for anemia and neutropenia, liver function tests
geriatric
over 65 yearsinitiate at lower end of dosing range
use with caution due to limited clinical trial data in this population; assess renal and hepatic function
monitor renal function (creatinine clearance), liver function, and hematologic parameters
Use with caution and monitor for adverse effects.
renal_impairment
severedose reduction recommended; 100 mg every 6-8 hours for CrCl less than 10 mL/min
adjust dose based on creatinine clearance; monitor drug levels if available
frequent monitoring of renal function, CBC, and drug tolerability
Use with caution and monitor for adverse effects.
hepatic_impairment
moderate to severedose reduction to 50-75% of standard dose recommended
use with caution; monitor liver function tests closely
regular liver function tests, bilirubin, and hematologic monitoring
Use with caution and monitor for adverse effects.
Statistics and clinical data
FDA approval year
Initial FDA approval for zidovudine
Drug class
Antiretroviral drug classification
Common uses
Primary therapeutic applications
Mechanism of action
Pharmacological mechanism
Treatment of HIV-1 infection in combination with other antiretroviral agents. May also be used for prevention of mother-to-child transmission of HIV during pregnancy when appropriate.
As a nucleoside reverse transcriptase inhibitor (NRTI), zidovudine is phosphorylated intracellularly to its active form, which competes with natural substrates and gets incorporated into viral DNA, causing chain termination and preventing viral replication.
Should be used as part of combination therapy, not as monotherapy. May cause hematologic toxicity including anemia and neutropenia. Regular monitoring of blood counts is recommended. Not a cure for HIV; continues to carry risk of opportunistic infections and complications.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy