Pregnancy Risk Category C
How supplied
Capsules: 100 mg
Tablets: 300 mg
Syrup: 50 mg/5 ml
Injection: 10 mg/ml
Action
Inhibits replication of HIV by blocking DNA synthesis.
Indications & dosage
Symptomatic HIV infection, including AIDS-
Adults and children ages 12 and older: 100 mg P.O. q 4 hours around the clock, 300 mg (1 tablet) P.O. q 12 hours, 200 mg P.O. q 8 hours, or 1 mg/kg I.V. q 4 hours six times daily.
Children ages 3 months to 12 years: 180 mg/m2 P.O. q 6 hours (720 mg/m2/
day), not to exceed 200 mg q 6 hours.
Asymptomatic HIV infection-
Adults and children ages 12 and older: 100 mg P.O. q 4 hours while awake (500 mg daily). Or, 1 mg/kg I.V. q 4 hours while awake (5 mg/kg/day).
Children ages 3 months to 12 years: 180 mg/m2 P.O. q 6 hours (720 mg/m2/day), not to exceed 200 mg q 6 hours.
To reduce risk of transmission of HIV from infected mother with a baseline CD4+ lymphocyte count exceeding 200 cells/mm3 to the newborn-
Adults: 100 mg P.O. five times daily given initially between 14 and 34 weeks' gestation and continued throughout pregnancy. During labor, administer loading dose of 2 mg/kg I.V. over 1 hour followed by continuous I.V. infusion of 1 mg/kg/hour until umbilical cord is clamped.
Neonates: 2 mg/kg P.O. (syrup) q 6 hours for 6 weeks, beginning within 12 hours after birth. Or, 1.5 mg/kg I.V. q 6 hours.
Therapy with zalcitabine or other antiretroviral agents for treatment of advanced HIV disease-
Adults and children ages 13 and older: 200 mg P.O. q 8 hours or 300 mg (1 tablet) P.O. q 12 hours given with zalcitabine 0.75 mg P.O. q 8 hours or other antiretroviral agents.
Adjust-a-dose: For patient with end-stage renal disease or patient receiving hemodialysis or peritoneal dialysis, 100 mg P.O. or 1 mg/kg I.V. q 6 to 8 hours.
Adverse reactions
CNS: headache, seizures, paresthesia, malaise, insomnia, asthenia, dizziness, somnolence.
GI: nausea, anorexia, abdominal pain, vomiting, constipation, diarrhea, taste perversion, dyspepsia, pancreatitis.
Hematologic: severe bone marrow suppression, anemia, agranulocytosis, thrombocytopenia.
Hepatic: increased liver enzyme levels.
Musculoskeletal: myalgia.
Skin: rash.
Other: diaphoresis, fever, lactic acidosis.
Interactions
Drug-drug: Acetaminophen, aspirin, indomethacin: may impair hepatic metabolism of zidovudine, increasing drug's toxicity. Monitor closely.
Acyclovir: possible seizures, lethargy, and fatigue. Use together cautiously.
Amphotericin B, dapsone, flucytosine, pentamidine: increased risk of nephrotoxicity and bone marrow suppression. Monitor closely.
Fluconazole, methadone, valproic acid: increased zidovudine level. Monitor for toxicity.
Ganciclovir, interferon-alpha: increased risk of hematologic toxicity. Monitor closely.
Other cytotoxic drugs: additive adverse effects on the bone marrow. Avoid concomitant use.
Probenecid: may decrease the renal clearance of zidovudine. Avoid concomitant use.
Ribavirin: antagonized antiviral activity of zidovudine against HIV. Avoid concomitant use.
Effects on diagnostic tests
Drug may cause depression of formed elements (erythrocytes, leukocytes, and platelets) in peripheral blood.
Contraindications
Contraindicated in patients with hypersensitivity to drug.
Nursing considerations
I.V. administration
Patient teaching
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING