ATAZOR R TABLET

🛡️🧬 Atazanavir 300 mg + Ritonavir 100 mg Tablet: Potent Boosted Protease Inhibitor for HIV Treatment

The fixed-dose combination of Atazanavir 300 mg and Ritonavir 100 mg (often referred to as ATV/r) is a powerful and convenient once-daily protease inhibitor regimen used for the treatment of HIV‑1 infection. This co-formulation combines the primary antiviral agent, atazanavir, with ritonavir as a pharmacokinetic enhancer, strengthening its effectiveness and simplifying therapy.

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🔬 Mechanism of Action

• Atazanavir is an HIV protease inhibitor, which blocks the action of the viral protease enzyme critical for cleaving immature viral proteins, thereby halting the formation of mature, infectious virions Mayo Clinic+15Wikipedia+151mg+15FDA Access DataWikipedia.

• Ritonavir, another protease inhibitor, is used in low doses not primarily for its antiviral effect, but to inhibit CYP3A4 enzymes, significantly increasing atazanavir blood concentrations and prolonging its action .

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📌 Indications and Patient Suitability

• Approved for HIV‑1 infection, this combination is used in both treatment-naïve and treatment‑experienced patients, ≥6 years old and ≥35–40 kg, as part of a combination antiretroviral therapy European Medicines Agency (EMA)+2FDA Access Data+2FDA Access Data+2.

• It is also used during pregnancy, with dosing adjustments for some co‑medications, offering a once-daily option aligned with maternal health Wikipedia+9FDA Access Data+9aidsmap.com+9.

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💊 Dosage & Administration

• Dose: One tablet (Atazanavir 300 mg + Ritonavir 100 mg) once daily with food Medscape Reference+8FDA Access Data+8aidsmap.com+8.

• Food intake improves absorption; antacids and proton-pump inhibitors may require timing adjustments to mitigate reduced atazanavir exposure Wikipedia+2FDA Access Data+2FDA Access Data+2.

• Renal impairment: No dose adjustment needed. Safe in patients on dialysis for treatment-naïve; avoid in treatment-experienced ESRD patients on hemodialysis Hopkins Guides+10FDA Access Data+10Medscape Reference+10.

• Hepatic impairment: Use not recommended due to limited safety data aidsmap.com+1European Medicines Agency (EMA)+1.

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⚠️ Warnings & Precautions

• Contraindications: Known hypersensitivity to components; interacting medications dependent on CYP3A/UGT1A1, including rifampin, lovastatin, simvastatin, St. John’s wort, certain antiarrhythmics, benzodiazepines, and PDE‑5 inhibitors Wikipedia+2FDA Access Data+2FDA Access Data+2.

• Cardiac conduction: Can prolong PR interval—monitor in those with heart block or on bradycardia-inducing drugs FDA Access Data.

• Hyperbilirubinemia: Atazanavir inhibits UGT1A1, leading to indirect bilirubin elevation, often resulting in mild, reversible jaundice FDA Access Data+2Wikipedia+2FDA Access Data+2.

• Liver disease: Use with extreme caution; avoid in moderate/severe hepatic impairment .

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🤒 Adverse Events

Common side effects include:

• Indirect hyperbilirubinemia, potentially visible as scleral or skin jaundice

• Gastrointestinal symptoms: nausea, diarrhea, abdominal pain

• CNS effects: headache, insomnia, peripheral neuropathy

• Metabolic issues: gastrointestinal discomfort, fat redistribution (“buffalo hump”)

• Rare: cardiac conduction abnormalities, gallbladder disorders, kidney stones .

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🔄 Drug Interactions

• Strong CYP3A inducers (e.g., rifampin, St. John’s wort) lower atazanavir efficacy and risk resistance .

• CYP3A substrates (e.g., simvastatin): risk elevated plasma levels—contraindicated .

• Antacids, PPIs, and H2 blockers affect absorption; staggered dosing recommended .

• PDE‑5 inhibitors, antiarrhythmics, and benzodiazepines: require caution due to possible toxicity .

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🧊 Monitoring & Patient Guidance

• Monitor Liver function, bilirubin, renal parameters, and heart conduction (ECG) periodically.

• Educate patients on taking tablets with meals, avoiding contraindicated medications or herbs, and on potential reversible jaundice.

• Emphasize adherence, as missed doses may result in viral breakthrough .

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📝 Summary

Atazanavir 300 mg + Ritonavir 100 mg offers a simple, effective, once-daily regimen for HIV‑1 therapy, combining powerful viral suppression with boosted pharmacokinetics. Its favorable dosing profile makes it a cornerstone ARV option—especially in resource-rich and -limited settings—thanks to efficacy in diverse patient populations, including pregnant women. With cautious selection and regular monitoring, it remains a pivotal component of modern antiretroviral therapy.

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Always follow your doctor’s advice, dosage instructions, and never self-medicate.