Home Drug Guide Atazanavir Sulfate and Ritonavir

Drug Guide

Generic Name

Atazanavir Sulfate and Ritonavir

Brand Names Evotaz

Classification

Therapeutic: Antiretroviral for HIV infection

Pharmacological: Protease inhibitor (Atazanavir), Pharmacokinetic enhancer (Ritonavir)

FDA Approved Indications

  • Treatment of HIV-1 infection in combination with other antiretroviral agents

Mechanism of Action

Atazanavir inhibits the HIV-1 protease enzyme, preventing viral maturation. Ritonavir inhibits cytochrome P450 3A-mediated metabolism, boosting atazanavir levels by increased bioavailability and plasma concentrations.

Dosage and Administration

Adult: Typically, one tablet once daily, with or without food. Dose adjustments may be needed based on concomitant medications.

Pediatric: Not generally approved for children under 6 years or below 15 kg.

Geriatric: No specific dosage adjustment based solely on age; evaluate for concomitant conditions and medications.

Renal Impairment: No dose adjustment needed.

Hepatic Impairment: Use with caution; specific adjustments not well established.

Pharmacokinetics

Absorption: Well absorbed with food, which enhances absorption.

Distribution: Widely distributed, crosses blood-brain barrier.

Metabolism: Metabolized primarily by CYP3A4 enzyme.

Excretion: Mostly fecal excretion, minor renal excretion.

Half Life: Approximately 7 hours for atazanavir; ritonavir has a half-life of about 3-5 hours.

Contraindications

  • Hypersensitivity to atazanavir, ritonavir, or any component.
  • Concurrent use with drugs highly dependent on CYP3A for clearance and associated with significant risk of Torsades de Pointes (e.g., astemizole, cisapride).

Precautions

  • Use with caution in patients with hepatic impairment, history of cardiovascular disease, or a history of bilirubin disorders. Liver function monitoring is advised.

Adverse Reactions - Common

  • Nausea (Frequent)
  • Headache (Common)
  • Rash (Common)
  • Elevated bilirubin (jaundice) (Common)

Adverse Reactions - Serious

  • Cardiac arrhythmias (QT prolongation, Torsades de Pointes) (Uncommon)
  • Hepatotoxicity (Uncommon)
  • Severe skin reactions (Stevens-Johnson syndrome) (Rare)

Drug-Drug Interactions

  • Drugs highly dependent on CYP3A4 for clearance (e.g., certain statins, sildenafil)

Drug-Food Interactions

  • High-fat meals may alter absorption.
  • Avoid excessive alcohol due to hepatotoxicity risk.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor liver function tests, lipid profile, and serum bilirubin.

Diagnoses:

  • Risk for hepatotoxicity
  • Impaired medication adherence

Implementation: Administer with food, educate about adherence, monitor for adverse reactions.

Evaluation: Assess viral load and CD4 counts periodically.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report signs of liver damage (jaundice, dark urine), allergic reactions, or severe skin reactions.
  • Avoid alcohol and certain medications without consulting healthcare provider.

Special Considerations

Black Box Warnings:

  • QT prolongation and Torsades de Pointes risk

Genetic Factors: Patients with HLA-B*57:01 allele may have increased risk of hypersensitivity reactions.

Lab Test Interference: May cause benign hyperbilirubinemia, leading to scleral icterus and jaundice.

Overdose Management

Signs/Symptoms: Nausea, vomiting, dizziness, symptoms of potential cardiac arrhythmias.

Treatment: Supportive care, activated charcoal if ingestion was recent, cardiac monitoring if arrhythmias are suspected.

Storage and Handling

Storage: Store at room temperature, away from moisture and heat.

Stability: Stable for at least 2 years when stored properly.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.