Atazanavir & Ritonavir Tablet

Q1: What is Atazanavir + Ritonavir (Atazor-R) used for?

Atazanavir/Ritonavir is a boosted protease inhibitor (PI) used as part of combination HIV-1 therapy. It is prescribed for both treatment-naive and treatment-experienced patients, particularly where an NNRTI cannot be used.

Q2: How does Atazanavir work to suppress HIV?

Atazanavir inhibits HIV protease enzyme, which cuts the long HIV polyprotein chain into functional viral proteins. Without protease activity, immature, non-infectious viral particles are produced — preventing new HIV from being able to infect cells.

Q3: Why must Atazanavir be taken with Ritonavir?

Ritonavir is a pharmacokinetic booster that inhibits CYP3A4 liver enzymes, dramatically increasing Atazanavir blood levels. Without Ritonavir, Atazanavir is metabolised too quickly and does not reach therapeutic concentrations. The standard dose is Atazanavir 300mg + Ritonavir 100mg.

Q4: Why does Atazanavir cause yellowing of skin or eyes?

Atazanavir inhibits UGT1A1, an enzyme that processes bilirubin. This raises unconjugated bilirubin, causing benign jaundice (yellow skin/eyes) in up to 40% of patients. This is generally harmless and not a sign of liver damage, but should be distinguished from true hepatotoxicity.

Q5: How is Atazor-R taken?

Take once daily with food — food significantly enhances Atazanavir absorption. Take consistently at the same time each day. Antacids and proton pump inhibitors significantly reduce absorption and should be managed carefully with your HIV specialist.

Q6: What are the most common side effects?

Jaundice (benign bilirubin elevation), nausea, diarrhea, abdominal pain, and headache are most common. Jaundice from bilirubin elevation is harmless but may cause cosmetic concerns.

Q7: What serious side effects require emergency care?

Seek immediate care for: signs of true liver damage (severe right-side abdominal pain, dark urine with fatigue — beyond benign bilirubin rise), cardiac conduction problems (PR interval prolongation — palpitations, dizziness), or kidney stones (severe flank pain, blood in urine).

Q8: Does Atazanavir affect the heart rhythm?

Yes. Atazanavir can prolong the PR interval on ECG, rarely causing first-degree AV block or other arrhythmias. Caution is needed in patients with pre-existing conduction abnormalities or those on other PR-prolonging drugs.

Q9: Can Atazanavir cause kidney stones?

Yes. Atazanavir is excreted in urine and can crystallise, forming kidney stones in a subset of patients (~2%). Adequate daily hydration helps prevent stone formation. Report severe flank pain to your doctor promptly.

Q10: What drug interactions affect Atazor-R?

Proton pump inhibitors (omeprazole, pantoprazole) substantially reduce Atazanavir absorption and should be avoided or managed. H2 blockers and antacids require timing adjustments. Strong CYP3A4 inducers reduce efficacy. Statins, immunosuppressants, and many other drugs interact — comprehensive review is essential.

Q11: Can Atazor-R be used during pregnancy?

Atazanavir/ritonavir can be used in pregnancy, though unboosted Atazanavir is preferred in some guidelines to avoid bilirubin neonatal concerns. The complete regimen should be managed by an HIV/obstetric specialist team.

Q12: Do I need a prescription for Atazor-R?

Yes. Atazanavir/Ritonavir is a prescription-only specialist antiretroviral requiring HIV specialist management, regular viral load monitoring, and careful drug interaction review.