Drug Guide
Zidovudine
Classification
Therapeutic: Antiretroviral agent, HIV/AIDS treatment
Pharmacological: Nucleoside reverse transcriptase inhibitor (NRTI)
FDA Approved Indications
- HIV-1 infection in adults and children; Prevention of maternal transmission of HIV
Mechanism of Action
Zidovudine is a nucleoside analog reverse transcriptase inhibitor that incorporates into viral DNA during reverse transcription, leading to chain termination and inhibition of viral replication.
Dosage and Administration
Adult: 200 mg orally every 4 hours or 300 mg twice daily, with dose adjustments based on renal function.
Pediatric: Dosage based on body weight; typically 4 mg/kg every 4 hours, up to a maximum dose.
Geriatric: Use with caution; monitor for adverse effects and organ function.
Renal Impairment: Reduce dosage based on degree of impairment.
Hepatic Impairment: Use with caution; there are limited data, so monitor closely.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed into body tissues and fluids.
Metabolism: Primarily metabolized in the liver to inactive metabolites.
Excretion: Primarily excreted via the kidneys; dose adjustment needed in renal impairment.
Half Life: Approximately 1.1 hours.
Contraindications
- Hypersensitivity to zidovudine or any component of the formulation.
Precautions
- Use with caution in anemia, neutropenia, or hepatic impairment; monitoring blood counts recommended.
Adverse Reactions - Common
- Headache (Common)
- Nausea (Common)
- Asthenia (Common)
- Myelosuppression (anemia, neutropenia) (Serious)
Adverse Reactions - Serious
- Lactic acidosis and hepatic steatosis (Serious, life-threatening)
- Severe anemia or neutropenia requiring discontinuation (Serious)
Drug-Drug Interactions
- Other myelosuppressive agents, hepatotoxic drugs, and drugs affecting bone marrow.
Drug-Food Interactions
- No significant interactions noted.
Drug-Herb Interactions
- Limited data; converse with caution when using herbal supplements with potential hematologic or hepatic effects.
Nursing Implications
Assessment: Monitor blood counts (CBC), liver function tests, and signs of anemia or neutropenia.
Diagnoses:
- Risk for infection due to immunosuppression,
- Risk for bleeding due to anemia.
Implementation: Administer as prescribed, monitor laboratory parameters, assess for symptoms of adverse effects.
Evaluation: Evaluate effectiveness (reduction in viral load) and adverse effects regularly.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report symptoms of anemia, unusual fatigue, or signs of infection.
- Avoid alcohol and hepatotoxic drugs.
- Use barrier methods to prevent HIV transmission.
Special Considerations
Black Box Warnings:
- Severe severe, life-threatening lactic acidosis and hepatic failure have been reported.
Genetic Factors: Genetic mutations may affect metabolism, but no routine testing is currently standard.
Lab Test Interference: May cause reversible elevations in serum transaminases and serum bilirubin.
Overdose Management
Signs/Symptoms: Nausea, vomiting, anemia, lactic acidosis, and possibly coma.
Treatment: Supportive care, interruption of drug therapy, and monitoring of vital signs and laboratory parameters.
Storage and Handling
Storage: Store at 20°C to 25°C (68°F to 77°F); protect from light.
Stability: Stable under recommended storage conditions.