Nurses Compass
Drug Guide
Atazanavir Sulfate
Classification
Therapeutic: Antiretroviral agent, Protease inhibitor
Pharmacological: HIV-1 protease inhibitor
FDA Approved Indications
- Treatment of HIV-1 infection in combination with appropriate antiretroviral agents
Mechanism of Action
Atazanavir inhibits the HIV-1 protease enzyme, preventing viral maturation and production of infectious virus particles.
Dosage and Administration
Adult: Typically 300 mg once daily with food. Dose adjustments may be necessary based on co-administered drugs.
Pediatric: Safety and efficacy established for patients ≥6 years old weighing ≥25 kg; dosing should be determined by a healthcare provider.
Geriatric: No specific dosage adjustments recommended, but caution in older adults due to potential comorbidities.
Renal Impairment: No dosage adjustment needed for mild to moderate impairment; caution advised in severe impairment.
Hepatic Impairment: Use with caution; dose adjustment may be necessary especially in severe hepatic impairment.
Pharmacokinetics
Absorption: Well-absorbed when taken with food
Distribution: Widely distributed; high protein binding (~86%)
Metabolism: Primarily via CYP3A4, with some contribution from CYP2D6
Excretion: Primarily fecal (via biliary excretion), minimal renal excretion
Half Life: Approximately 6-7 hours
Contraindications
- Hypersensitivity to atazanavir or any component of the formulation
Precautions
- Use with caution in patients with underlying cardiac conduction abnormalities, hepatic impairment, or concerning jaundice.
Adverse Reactions - Common
- Hyperbilirubinemia (often leading to jaundice or scleral icterus) (Frequent)
- Nausea, rash, headache (Common)
Adverse Reactions - Serious
- QT prolongation, and PR interval prolongation leading to potential cardiac arrhythmias (Serious but rare)
- Severe skin reactions, hepatotoxicity, immune reconstitution syndrome (Serious but rare)
Drug-Drug Interactions
- Atazanavir is a substrate and inhibitor of CYP3A4; hold or adjust doses of concomitant drugs accordingly.
- Calcium or magnesium-containing antacids, acid reducers (PPI, H2 antagonists) may decrease absorption. Use antacids 2 hours before or after atazanavir.
- Metformin, statins, and other drugs metabolized by CYP3A4 and UDP-glucuronosyltransferases may have altered levels.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for signs of hepatic dysfunction, skin reactions, cardiovascular abnormalities, and changes in bilirubin levels.
Diagnoses:
- Risk for hepatotoxicity, skin rash, or cardiac rhythm disturbances.
Implementation: Administer with food; monitor liver function tests, complete blood counts, and cardiac status.
Evaluation: Assess viral load and CD4 counts to evaluate efficacy.
Patient/Family Teaching
- Take medication as prescribed, with food.
- Report symptoms of jaundice, severe skin rash, or allergic reactions.
- Avoid unprescribed medications, especially acid reducers, without consultation.
- Maintain regular follow-up visits for lab monitoring.
Special Considerations
Black Box Warnings:
- None currently established for atazanavir.
Genetic Factors: None specific.
Lab Test Interference: May cause benign hyperbilirubinemia, which can be mistaken for liver dysfunction; monitor liver function accordingly.
Overdose Management
Signs/Symptoms: Nausea, vomiting, dizziness, or other gastrointestinal symptoms.
Treatment: Supportive care; no specific antidote. Consider gastric lavage or activated charcoal if ingestion is recent.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F). Keep in original container.
Stability: Stable under recommended storage conditions.