Comprehensive Guide to Atazanavir: Uses, Dosage, Side Effects, and More

What is Atazanavir?

Overview

Generic Name: Atazanavir

Brand Name: Reyataz, generics

Drug Group: Protease inhibitor (antiretroviral)

Commonly Used For

• Treat HIV-1 infection in adults and children (6 years and older).
• Prevent mother-to-child transmission of HIV when used as part of a regimen.
• Off-label uses include post-exposure prophylaxis (PEP) under specialist guidance.

Key Characteristics

Form: Capsules (150 mg, 200 mg, 300 mg) and oral powder (50 mg per packet).

Mechanism: Inhibits HIV-1 protease, blocking viral maturation.

Approval: FDA-approved (2003 for Reyataz) and EMA-approved for HIV treatment.

Indications and Uses of Atazanavir

HIV-1 Infection: Treats HIV-1 in combination with other antiretroviral drugs in adults and children (6 years and older).

Prevention: Reduces perinatal HIV transmission when included in a regimen.

Off-Label Uses: Used in PEP following occupational or non-occupational exposure under specialist supervision.

Dosage of Atazanavir

Dosage for Adults

HIV-1 Treatment (with ritonavir boosting): 300 mg once daily with 100 mg ritonavir, taken with food.

HIV-1 Treatment (without ritonavir, with tenofovir): 400 mg once daily with food.

Treatment-Naïve Patients: 300 mg/100 mg ritonavir once daily, with food.

Dosage for Children

6 years and older (weight-based):

• 15–<20 kg: 150 mg with 100 mg ritonavir once daily.
• 20–<40 kg: 200 mg with 100 mg ritonavir once daily.
• ≥40 kg: 300 mg with 100 mg ritonavir once daily.
• All doses taken with food.

Dosage for Pregnant Women

Pregnancy Category B: Use 300 mg/100 mg ritonavir once daily with food; monitor viral load. Consult an infectious disease specialist or obstetrician.

Dosage Adjustments

Renal Impairment:

• CrCl <70 mL/min: No adjustment; monitor for kidney stones.
• Dialysis: 300 mg/100 mg ritonavir once daily, post-dialysis.

Hepatic Impairment:

• Mild (Child-Pugh A): No adjustment.
• Moderate (Child-Pugh B): Reduce to 300 mg once daily (without ritonavir).
• Severe (Child-Pugh C): Avoid use.

Elderly: No specific adjustment; monitor for tolerability.

Additional Considerations

• Take this active ingredient with food to enhance absorption.
• Avoid missing doses to prevent viral resistance.

How to Use Atazanavir

Administration: Swallow capsules whole or mix oral powder with food (e.g., yogurt) and take with food; do not chew granules.

Timing: Take once daily, with a meal, at the same time each day.

Monitoring: Watch for signs of jaundice, kidney pain, or rash.

Additional Tips:

• Take with ritonavir or as part of a prescribed regimen.
• Report severe abdominal pain or yellowing of skin immediately.

Contraindications for Atazanavir

• Patients with hypersensitivity to Atazanavir or its components.
• Patients with severe hepatic impairment (Child-Pugh C).
• Concurrent use with certain drugs (e.g., rifampin, irinotecan) due to interactions.

Warnings & Precautions for Atazanavir

General Warnings

Hepatotoxicity: Risk of liver injury; monitor liver function tests.

Hyperbilirubinemia: May cause jaundice; not typically harmful but monitor.

Nephrolithiasis: Risk of kidney stones; ensure adequate hydration.

PR Interval Prolongation: Risk of heart rhythm changes; use cautiously.

Immune Reconstitution Syndrome: Possible in HIV patients starting therapy.

Use in Specific Populations

Pregnancy: Category B; use with monitoring.

Breastfeeding: Excreted in breast milk; avoid during treatment.

Elderly: Increased risk of side effects; monitor closely.

Children: Approved for 6 years and older; monitor growth.

Renal/Hepatic Impairment: Adjust or avoid in severe cases; monitor closely.

Additional Precautions

• Inform your doctor about liver disease, kidney issues, or other medications before starting this medication.
• Avoid antacids or buffered medications within 2 hours of dosing.

Overdose and Management of Atazanavir

Overdose Symptoms

• Jaundice or severe hyperbilirubinemia.
• Nausea or vomiting.
• Kidney pain or cardiac conduction issues.

Immediate Actions

Contact Emergency Services: Call 911 or seek immediate medical help.

Supportive Care: Provide hydration, monitor liver and kidney function, and manage symptoms.

Monitor: Check ECG, bilirubin levels, and renal parameters.

Additional Notes

• Overdose is rare with proper dosing; store securely.
• Report persistent symptoms promptly.

Side Effects of Atazanavir

Common Side Effects

• Jaundice (yellowing of skin/eyes, 10–15%)
• Nausea (5–10%)
• Headache (3–7%)
• Diarrhea (2–5%)

These effects may decrease over time.

Serious Side Effects

Seek immediate medical attention for:

• Hepatic: Severe liver pain or dark urine.
• Renal: Kidney stones or flank pain.
• Cardiac: Irregular heartbeat or fainting.
• Allergic: Rash or anaphylaxis (rare).

Additional Notes

• Regular monitoring for liver and kidney function is essential.
• Report any unusual symptoms immediately.

Drug Interactions with Atazanavir

This active ingredient may interact with:

Acid-Reducing Agents (e.g., Omeprazole): Reduce Atazanavir absorption; separate by 12 hours.

CYP3A4 Inhibitors (e.g., Ritonavir): Increase levels; used intentionally for boosting.

CYP3A4 Inducers (e.g., Rifampin): Decrease levels; avoid concurrent use.

Statins (e.g., Atorvastatin): Increased risk of myopathy; adjust dose.

Patient Education or Lifestyle

Pharmacokinetics

Absorption: Well-absorbed with food; peak plasma concentration at 2–4 hours.

Distribution: Volume of distribution ~107 L; 86% protein-bound.

Metabolism: Hepatic via CYP3A4 and UGT1A1 to inactive metabolites.

Excretion: Primarily fecal (79%) and urinary (13%).

Half-Life: 6.5–7.9 hours (with ritonavir boosting extends to 18.6 hours).

Pharmacodynamics

This drug exerts its effects by:

• Inhibiting HIV-1 protease, preventing viral particle maturation.
• Reducing viral load when used with other antiretrovirals.
• Offering a once-daily dosing option with ritonavir boosting.
• Effective in treatment-naïve and experienced HIV patients.

Storage of Atazanavir

Temperature: Store at 20–25°C (68–77°F); excursions permitted to 15–30°C (59–86°F).

Protection: Keep in original container to shield from moisture.

Safety: Store out of reach of children.

Disposal: Dispose of unused capsules or powder per local regulations or consult a pharmacist.

Frequently Asked Questions (FAQs)

Q: What does Atazanavir treat?
A: This medication treats HIV-1 infection.

Q: Can this active ingredient cause jaundice?
A: Yes, jaundice is common; report yellowing of skin or eyes immediately.

Q: Is Atazanavir safe for children?
A: Approved for 6 years and older; consult a doctor.

Q: How is this drug taken?
A: Once daily as a capsule or oral powder, with food.

Q: How long is Atazanavir treatment?
A: Lifelong for HIV management, with regular monitoring.

Regulatory Information

This medication is approved by:

U.S. Food and Drug Administration (FDA): Approved in 2003 (Reyataz) for HIV treatment.

European Medicines Agency (EMA): Approved for similar indications.

Other Agencies: Approved globally for equivalent uses; consult local guidelines.

References

1. U.S. Food and Drug Administration (FDA). (2023). Reyataz (Atazanavir) Prescribing Information.
   • Official FDA documentation detailing the drug’s approved uses, dosage, and safety.
2. European Medicines Agency (EMA). (2023). Atazanavir Summary of Product Characteristics.
   • EMA’s comprehensive information on the medication’s indications and precautions in Europe.
3. National Institutes of Health (NIH). (2023). Atazanavir: MedlinePlus Drug Information.
   • NIH resource providing detailed information on the drug’s uses, side effects, and precautions.
4. World Health Organization (WHO). (2023). WHO Model List of Essential Medicines: Atazanavir.
   • WHO’s inclusion of Atazanavir for HIV treatment.
5. Journal of Antimicrobial Chemotherapy. (2020). Atazanavir in HIV Management.
   • Peer-reviewed article on Atazanavir efficacy (note: access may require a subscription).