Zidovudine
FDA Drug Information • Also known as: Retrovir, Zidovudine
- Brand Names
- Retrovir, Zidovudine
- Dosage Form
- CAPSULE
- Product Type
- DRUG FOR FURTHER PROCESSING
⚠ Boxed Warning (Black Box)
WARNING: RISK OF HEMATOLOGICAL TOXICITY, MYOPATHY, LACTIC ACIDOSIS AND SEVERE HEPATOMEGALY WITH STEATOSIS RETROVIR (zidovudine) capsules, oral solution, and injection have been associated with hematologic toxicity including neutropenia and severe anemia, particularly in patients with advanced HIV-1 disease [see Warnings and Precautions ( 5.1 )] . Prolonged use of RETROVIR has been associated with symptomatic myopathy [see Warnings and Precautions ( 5. 2)] . Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination, including RETROVIR and other antiretrovirals. Suspend treatment if clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity occur [see Warnings and Precautions ( 5. 3)] . WARNING: RISK OF HEMATOLOGICAL TOXICITY, MYOPATHY, LACTIC ACIDOSIS AND SEVERE HEPATOMEGALY WITH STEATOSIS See full prescribing information for complete boxed warning.
Hematologic toxicity including neutropenia and severe anemia have been associated with the use of zidovudine. ( 5.1 ) Symptomatic myopathy associated with prolonged use of zidovudine. ( 5.2 ) Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues including RETROVIR. Suspend treatment if clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity occur. ( 5.3 )Description
11 DESCRIPTION RETROVIR is the brand name for zidovudine (formerly called azidothymidine [AZT]), a pyrimidine nucleoside analogue active against HIV-1. The chemical name of zidovudine is 3′-azido-3′-deoxythymidine; it has the following structural formula: Zidovudine is a white to beige, odorless, crystalline solid with a molecular weight of 267.24 and a solubility of 20.1 mg per mL in water at 25°C. The molecular formula is C 10 H 13 N 5 O 4 . RETROVIR capsules are for oral administration. Each capsule contains 100 mg of zidovudine and the inactive ingredients corn starch, magnesium stearate, microcrystalline cellulose, and sodium starch glycolate. The 100-mg empty hard gelatin capsule, printed with edible black ink, consists of black iron oxide, dimethylpolysiloxane, gelatin, pharmaceutical shellac, soya lecithin, and titanium dioxide. Each mL of RETROVIR oral solution contains 10 mg of zidovudine and the inactive ingredients sodium benzoate 0.2% (added as a preservative), citric acid, flavors, glycerin, and liquid sucrose. Sodium hydroxide may be added to adjust pH. RETROVIR injection is a sterile solution for IV infusion only. Each mL contains 10 mg zidovudine in water for injection. Hydrochloric acid and/or sodium hydroxide may have been added to adjust the pH to approximately 5.5. RETROVIR injection contains no preservatives. zidovudine structural formula
What Is Zidovudine Used For?
1 INDICATIONS AND USAGE RETROVIR is a nucleoside analogue reverse transcriptase inhibitor indicated for:
Treatment of Human Immunodeficiency Virus (HIV-1) infection in combination with other antiretroviral agents. ( 1.1 ) Prevention of maternal-fetal HIV-1 transmission. ( 1.2 ) 1.1 Treatment of HIV-1 RETROVIR, a nucleoside reverse transcriptase inhibitor, is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. 1.2 Prevention of Maternal-Fetal HIV-1 Transmission RETROVIR is indicated for the prevention of maternal-fetal HIV-1 transmission [see Dosage and Administration ( 2.3 )]. The indication is based on a dosing regimen that included 3 components: 1. antepartum therapy of HIV‑1–infected mothers 2. intrapartum therapy of HIV‑1–infected mothers 3. post-partum therapy of HIV‑1–exposed neonate Points to consider prior to initiating RETROVIR in pregnant women for the prevention of maternal-fetal HIV-1 transmission include: In most cases, RETROVIR for prevention of maternal-fetal HIV-1 transmission should be given in combination with other antiretroviral drugs. Prevention of HIV-1 transmission in women who have received RETROVIR for a prolonged period before pregnancy has not been evaluated. Because the fetus is most susceptible to the potential teratogenic effects of drugs during the first 10 weeks of gestation and the risks of therapy with RETROVIR during that period are not fully known, women in the first trimester of pregnancy who do not require immediate initiation of antiretroviral therapy for their own health may consider delaying use; this indication is based on use after 14 weeks’ gestation.Dosage and Administration
2 DOSAGE AND ADMINISTRATION
Treatment of HIV-1 infection: Adults: Recommended oral dosage is 300 mg twice a day with other antiretroviral agents. For patients who are unable to take the oral formulations, the recommended intravenous dose is 1 mg per kg infused over 1 hour every 4 hours. ( 2.1 ) Pediatric patients (aged 4 weeks to less than 18 years): Dosage should be calculated based on body weight not to exceed adult dose. ( 2.2 ) Prevention of maternal-fetal HIV-1 transmission: Specific dosage instructions for mother and infant. ( 2.3 ) Patients with severe anemia and/or neutropenia: Dosage interruption may be necessary. ( 2.4 ) Renal impairment: Recommended oral dosage in hemodialysis or peritoneal dialysis or in patients with creatinine clearance (CrCl) less than 15 mL per minute is 100 mg every 6 to 8 hours. Equivalent intravenous dosing is approximately 1 mg per kg every 6 to 8 hours. ( 2.5 ) 2.1 Adults – Treatment of HIV-1 Infection Oral Dosing The recommended oral dose of RETROVIR is 300 mg twice daily in combination with other antiretroviral agents. Intravenous (IV) Dosing The recommended intravenous dose is 1 mg per kg infused at a constant rate over 1 hour every 4 hours. Patients should receive RETROVIR injection only until oral therapy can be administered. RETROVIR injection must be diluted prior to administration. The calculated dose should be removed from the 20-mL vial and added to 5% Dextrose injection solution to achieve a concentration no greater than 4 mg per mL. After dilution, the solution is physically and chemically stable for 24 hours at room temperature and 48 hours if refrigerated at 2°C to 8°C (36°F to 46°F). As an additional precaution, the diluted solution should be administered within 8 hours if stored at 25°C (77°F) or 24 hours if refrigerated at 2°C to 8°C to minimize potential administration of a microbially contaminated solution. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit and discarded if either is observed. Rapid infusion or bolus injection should be avoided. RETROVIR injection should not be given intramuscularly. 2.2 Pediatric Patients (Aged 4 Weeks to Less than 18 Years) Healthcare professionals should pay special attention to accurate calculation of the dose of RETROVIR, transcription of the medication order, dispensing information, and dosing instructions to minimize risk for medication dosing errors. Prescribers should calculate the appropriate dose of RETROVIR for each child based on body weight (kg) and should not exceed the recommended adult dose. Before prescribing RETROVIR capsules, children should be assessed for the ability to swallow capsules. If a child is unable to reliably swallow a RETROVIR capsule, the RETROVIR oral solution formulation should be prescribed. The recommended oral dosage in pediatric patients aged 4 weeks to less than 18 years and weighing greater...Side Effects (Adverse Reactions)
6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling:
Hematologic toxicity, including neutropenia and anemia [see Boxed Warning , Warnings and Precautions ( 5.1 )]. Symptomatic myopathy [see Boxed Warning , Warnings and Precautions ( 5. 2)]. Lactic acidosis and severe hepatomegaly with steatosis [see Boxed Warning , Warnings and Precautions ( 5. 3)]. Hepatic decompensation in patients co-infected with HIV-1 and hepatitis C [see Warnings and Precautions ( 5. 4)]. Most commonly reported adverse reactions (incidence greater than or equal to 15%) in adult HIV-1 clinical trials were headache, malaise, nausea, anorexia, and vomiting. ( 6.1 ) Most commonly reported adverse reactions (incidence greater than or equal to 15%) in pediatric HIV-1 clinical trials were fever and cough. ( 6.1 ) Most commonly reported adverse reactions in neonates (incidence greater than or equal to 15%) in the prevention of maternal-fetal transmission of HIV-1 clinical trial were anemia and neutropenia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact ViiV Healthcare at 1-877-844-8872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adults The frequency and severity of adverse reactions associated with the use of RETROVIR are greater in patients with more advanced infection at the time of initiation of therapy. Table 3 summarizes adverse reactions reported at a statistically significant greater incidence for subjects receiving oral RETROVIR in a monotherapy trial. Table 3. Percentage (%) of Subjects with Adverse Reactions (Greater than or Equal to 5% Frequency) in Asymptomatic HIV-1 Infection (ACTG 019) a Not statistically significant versus placebo. Adverse Reaction RETROVIR 500 mg/day (n = 453) Placebo (n = 428) Body as a whole Asthenia 9% a 6% Headache 63% 53% Malaise 53% 45% Gastrointestinal Anorexia 20% 11% Constipation 6% a 4% Nausea 51% 30% Vomiting 17% 10% In addition to the adverse reactions listed in Table 3 , adverse reactions observed at an incidence of greater than or equal to 5% in any treatment arm in clinical trials (NUCA3001, NUCA3002, NUCB3001, and NUCB3002) were abdominal cramps, abdominal pain, arthralgia, chills, dyspepsia, fatigue, insomnia, musculoskeletal pain, myalgia, and neuropathy. Additionally, in these trials hyperbilirubinemia was reported at an incidence of less than or equal to 0.8%. Selected laboratory abnormalities observed during a clinical trial of monotherapy with oral RETROVIR are shown in Table 4 . Table 4. Frequencies of Selected (Grade 3/4) Laboratory Abnormalities in Subjects with Asymptomatic HIV-1 Infection (ACTG 019) ULN = Upper limit of normal. Test (Abnormal Level) RETROVIR 500 mg/day (n = 453) Placebo (n = 428) Anemia (Hgb <8 g/dL) 1% <1% Granulocytopenia (<750 cells/mm 3 ) 2% 2% Thrombocytopenia (platelets <50,000/mm 3 ) 0% <1% ALT (>5 x ULN) 3% 3% AST (>5 x ULN) 1% 2% The adverse reactions reported during IV administration of RETROVIR injection are similar to those reported with oral administration; neutropenia and anemia were reported most frequently. Long-term IV administration beyond 2 to 4 weeks has not been studied in adults and may enhance hematologic adverse reactions. Local reaction, pain, and slight irritation during IV administration occur infrequently. Pediatrics The clinical adverse reactions reported among adult recipients of RETROVIR may also occur in pediatric patients. Trial ACTG 300: Selected clinical adverse reactions and physical findings with a greater than or equal to 5% frequency during therapy with EPIVIR (lamivudine) oral suspension 4 mg per kg twice daily plus RETROVIR 160 mg per m 2 3 times daily compared...Drug Interactions
7 DRUG INTERACTIONS
Avoid use with stavudine. ( 7.1 ) Avoid use with doxorubicin. ( 7.2 ) Bone marrow suppressive/cytotoxic agents: May increase the hematologic toxicity of zidovudine. ( 7.3 ) 7.1 Antiretroviral Agents Stavudine Concomitant use of zidovudine with stavudine should be avoided since an antagonistic relationship has been demonstrated in vitro. Nucleoside Analogues Affecting DNA Replication Some nucleoside analogues affecting DNA replication, such as ribavirin, antagonize the in vitro antiviral activity of RETROVIR against HIV-1; concomitant use of such drugs should be avoided. 7.2 Doxorubicin Concomitant use of zidovudine with doxorubicin should be avoided since an antagonistic relationship has been demonstrated in vitro. 7.3 Hematologic/Bone Marrow Suppressive/Cytotoxic Agents Coadministration of ganciclovir, interferon alfa, ribavirin, and other bone marrow suppressive or cytotoxic agents may increase the hematologic toxicity of zidovudine.Contraindications
4 CONTRAINDICATIONS RETROVIR is contraindicated in patients who have had a potentially life-threatening hypersensitivity reaction (e.g., anaphylaxis, Stevens-Johnson syndrome) to any of the components of the formulations. Hypersensitivity to zidovudine or any of the components (e.g., anaphylaxis, Stevens-Johnson syndrome). ( 4 )
Pregnancy and Breastfeeding
8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to RETROVIR during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Available data from the APR show no difference in the overall risk of birth defects for zidovudine compared with the background rate for birth defects of 2.7% in the Metropolitan Atlanta Congenital Defects Program (MACDP) reference population (see Data) . The APR uses the MACDP as the U.S. reference population for birth defects in the general population. The MACDP evaluates women and infants from a limited geographic area and does not include outcomes for births that occurred at less than 20 weeks’ gestation. The rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15% to 20%. The background risk for major birth defects and miscarriage for the indicated population is unknown. Hyperlactatemia, which may be due to mitochondrial dysfunction, has been reported in infants with in utero exposure to zidovudine-containing products. These events were transient and asymptomatic in most cases. There have been few reports of developmental delay, seizures, and other neurological disease. However, a causal relationship between these events and exposure to zidovudine-containing products in utero or peri-partum has not been established ( see Data) . In an animal reproduction study, administration of oral zidovudine to female rats prior to mating and throughout gestation resulted in embryotoxicity at doses that produced systemic exposure (AUC) approximately 33 times higher than exposure at the recommended clinical dose. However, no embryotoxicity was observed after oral administration of zidovudine to pregnant rats during organogenesis at doses that produced systemic...
Overdosage
10 OVERDOSAGE Acute overdoses of zidovudine have been reported in pediatric patients and adults. These involved exposures up to 50 grams. No specific symptoms or signs have been identified following acute overdosage with zidovudine apart from those listed as adverse events such as fatigue, headache, vomiting, and occasional reports of hematological disturbances. Patients recovered without permanent sequelae. Hemodialysis and peritoneal dialysis appear to have a negligible effect on the removal of zidovudine while elimination of its primary metabolite, 3′-azido-3′-deoxy-5′- O -β- D -glucopyranuronosylthymidine (GZDV), is enhanced. If overdose occurs, the patient should be monitored for evidence of toxicity and given standard supportive treatment as required.
How Supplied
16 HOW SUPPLIED/STORAGE AND HANDLING RETROVIR 100-mg capsules are supplied as white, opaque cap and body capsules containing 100 mg zidovudine per capsule. Each capsule is printed with “Wellcome” and unicorn logo on cap and “Y9C” and “100” on body. Bottles of 100 (NDC 49702-211-20). Store at 15° to 25°C (59° to 77°F) and protect from moisture. RETROVIR oral solution is supplied as a colorless to pale yellow, strawberry-flavored solution containing 10 mg zidovudine in each mL. Bottle of 240 mL (NDC 49702-212-48) with child-resistant cap. Store at 15° to 25°C (59° to 77°F). RETROVIR injection is a clear, colorless to slightly yellow aqueous solution. The strength of the presentation is 200 mg of zidovudine in 20 mL solution (10 mg per mL). Single-dose vial (NDC 49702-213-01), Carton of 5 (NDC 49702-213-26). Store vials at 15° to 25°C (59° to 77°F) and protect from light.
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.