Antiretroviral nucleoside reverse transcriptase inhibitor (NRTI)
Nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral, indicated in combination with other antiretrovirals for treatment of HIV-1 infection and for prevention of maternal-fetal HIV-1 transmission.
Also known as: Retrovir, AZT
DailyMed approved label (RETROVIR, zidovudine; setID e816e8f5-1e50-4f49-8bea-92da0121d26e)
DailyMed approved label (RETROVIR, zidovudine; setID e816e8f5-1e50-4f49-8bea-92da0121d26e)
Combining Zidovudine with Co-trimoxazole increases the risk of myelotoxicity (anaemia and neutropenia) through an additive effect on the bone marrow.
Zidovudine is associated with haematological toxicity, including neutropenia and severe anaemia, especially in patients with advanced HIV; co-trimoxazole, with its antifolate component (trimethoprim) and the bone marrow effect of sulfonamides, adds the risk of myelosuppression when used concomitantly (the combination is common in Pneumocystis prophylaxis in HIV). Monitor the blood count regularly during the combination, especially in the first months of treatment and in patients with low counts; consider folinic acid if folate depletion arises and adjust or interrupt zidovudine in the face of significant neutropenia or anaemia.
Co-trimoxazole + zidovudine: additive risk of myelosuppression (neutropenia and anaemia). Monitor the blood count in HIV prophylaxis.
Both drugs can induce haematological abnormalities; co-administration potentiates marrow suppression, especially in immunodeficient patients.
Periodic blood counts: haemoglobin, white cells and neutrophils.
Significant anaemia or neutropenia requires reassessing the combination.
Use Co-trimoxazole with Zidovudine only when strictly indicated (e.g. Pneumocystis prophylaxis) and with haematological monitoring.
DailyMed/FDA (NIH/NLM) — approved Zidovudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6df09f15-b102-431c-adde-d7aeef6f5d84 ; approved Co-trimoxazole label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=08500fcb-dbec-4ac2-91c3-189d27907ec0 — with additional reference: Prontuário Terapêutico do INFARMED, INFARMED (11th ed., 2012)
Alcohol may worsen zidovudine hepatotoxicity (especially in hepatitis B or C coinfection).
Limit or avoid alcohol intake during treatment.
DailyMed/FDA (NIH/NLM) — approved Zidovudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e816e8f5-1e50-4f49-8bea-92da0121d26e
Zidovudine can be taken with or without food; taking it with food may reduce nausea.
Take with food if nausea occurs.
DailyMed/FDA (NIH/NLM) — approved Zidovudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e816e8f5-1e50-4f49-8bea-92da0121d26e
Zidovudine is predominantly eliminated renally; in advanced renal impairment the dose should be reduced.
Adjust the dose in severe renal impairment; monitor renal function and blood count.
DailyMed/FDA (NIH/NLM) — approved Zidovudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e816e8f5-1e50-4f49-8bea-92da0121d26e
Zidovudine causes myelosuppression (anaemia, neutropenia); the risk increases in patients with prior low counts or B12/folate deficiency.
Monitor the blood count; adjust the dose or stop with severe anaemia or neutropenia.
DailyMed/FDA (NIH/NLM) — approved Zidovudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e816e8f5-1e50-4f49-8bea-92da0121d26e
Zidovudine is used in pregnancy to prevent vertical transmission of HIV; it is not a known teratogen at therapeutic doses.
Use in pregnancy as part of the HIV antiretroviral regimen; monitor maternal blood count (anaemia).
Excreted into breast milk; in HIV infection breastfeeding is not recommended regardless of treatment.
No specific additional contraception.
DailyMed/FDA (NIH/NLM) — approved Zidovudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e816e8f5-1e50-4f49-8bea-92da0121d26e
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
NRTI that inhibits HIV-1 reverse transcriptase, interrupting proviral DNA synthesis; intracellular phosphorylation to zidovudine triphosphate (active metabolite) competes with endogenous thymidine.
Competitive inhibition of viral reverse transcriptase by zidovudine triphosphate and proviral DNA chain termination; hematologic and mitochondrial toxicity relate to the AMT metabolite and gamma DNA polymerase inhibition.
Rapidly absorbed and extensively distributed orally (serum peaks at 0.5–1.5 h); mean oral bioavailability of 64% (±10); penetrates CSF (CSF/plasma ratio ~0.6).
Extensively metabolized in the liver (mainly glucuronidation to inactive GZDV; formation of the AMT metabolite); excretion is renal, mainly as the glucuronide metabolite.
Plasma half-life ~1 h in adults (half-life of ~13 h in neonates exposed in utero).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
