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Atazanavir

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Atazanavir, Atazanavir/r, Reyataz, ATV, ATV/r, Evotaz

  • See Also
  1. Anti-Retroviral Therapy
  2. Protease Inhibitor
  • Indications
  1. HIV Infection in Treatment Naive Patients (as part of combination therapy)
  • Contraindications
  1. Age <3 months old (Kernicterus risk)
  2. Severe hepatic Impairment (Child-Pugh Class C)
    1. Exercise caution in (Child-Pugh Class B) and consider Atrazanavir dose reduction
  3. Hemodialysis patients who are treament experienced
  • Mechanism
  1. See Protease Inhibitor
  • Medications
  1. Atazanavir (Rayataz)
    1. Typically combined wiith Ritonavir as separate tablet
    2. Capsules: 150, 200 and 300 mg
    3. Powder for Oral Solution: 50 mg
  2. Atazanavir with Cobicistat (Evotaz)
    1. Atazanavir/Cobicistat Tablet: 300 mg/150 mg
  • Dosing
  1. Combined with other Antiretroviral agents
  2. Take Atazanavir with food
  3. Adult
    1. Atazanavir 300 mg (400 mg when used with Efavirenz or Tenofovir, or H2 Blocker) AND
    2. Boosting Medication (one of the following)
      1. Ritonavir 100 mg OR
      2. Cobicistat 150 mg
  4. Child using powder solution (age >=3 months, weight <25 kg)
    1. Mix Atazanavir powder with food or liquid, followed immediately by Ritonavir
    2. Weight 5 to 15 kg: Atazanavir 200 mg AND Ritonavir 80 mg orally once daily
    3. Weight 15 to 25 kg: Atazanavir 250 mg AND Ritonavir 80 mg orally once daily
  5. Child using capsules (age >=6 years)
    1. Weight 15 to 35 kg: Atazanavir 200 mg AND Ritonavir 100 mg orally once daily
    2. Weight >35 kg: Atazanavir 300 mg AND Ritonavir 100 mg orally once daily
  • Adverse Effects
  1. See Protease Inhibitor for adverse effects attributed to the class
    1. Unlike most Protease Inhibitors, does not appear to cause significant Hyperlipidemia
  2. Indirect Hyperbilirubinemia
    1. Atazanavir inhibits UDP-glucuronosyl transferase (UGT)
    2. Poor UGT1A1 metabolizers may demonstrate Jaundice
    3. Risk of Kernicterus (contraindicated in age <3 months)
    4. Obtain baseline and periodic Liver Function Tests
    5. Exercise caution in (Child-Pugh Class B) and consider Atrazanavir dose reduction
  3. Rash (20%)
    1. Does not typically require stopping the medication
  4. Nephrolithiasis
  5. Interstitial Nephritis
    1. Obtain baseline and periodic Urinalysis and Renal Function tests
  6. Cholelithiasis
  7. EKG Abnormalities
    1. PR prolongation
    2. Second degree AV Block
    3. Other cardiac conduction abnormalities
  • Drug Interactions
  1. Multiple Drug Interactions related to Atazanavir as a CYP1A2 Inhibitor, CYP2C9 Inhibitor, CYP3A4 inhibitor
    1. As with other Protease Inhibitors, check a formal Drug Interaction application before prescribing
  2. Acid suppressants (Proton Pump Inhibitors, H2 Blockers)
    1. Atrazanavir requires acid in Stomache for absorption
    2. Proton Pump Inhibitors can render Atrazanavir ineffective and results in a high risk of developing resistance
      1. Avoid concurrent use in treatment experienced patients
      2. If PPIs are used, limit to Omeprazole 20 mg/day spaced 12 hours from Atrazanavir dose
    3. H2 Blockers
      1. Dose of Atazanavir is increased to 400 mg/day
      2. Dose H2 Blocker either at same time or at least 10 hours before
      3. Limit dose to Famotidine 40 mg twice daily (treatment naive) or 20 mg twice daily (experienced)
    4. Antacid Salts (or buffered Didanosine)
      1. Give Atazanavir 2 hours before or 1 hour after
  3. Tenofovir
    1. Dose of Atazanavir is increased to 400 mg/day
  4. Indinavir
    1. Contraindicated (risk of worsened Hyperbilirubinemia)
  5. Nevirapine
    1. Contraindicated
  6. Clarithromycin
    1. Decrease Clarithromycin dose 50% and consider alternative agents (e.g. for Mycobacterium Avium Complex)
  7. Voriconazole
    1. Ritonavir decreases Voriconazole levels and efficacy
    2. Avoid concurrent use if possible
  8. Diltiazem
    1. Consider reducing Diltiazem dose by 50%
    2. Monitor EKG
  9. Seizure Medications (Carbamazepine, Lamotrigine, Phenobarbital, Phenytoin)
    1. Monitor drug levels
  10. Buprenorphine
    1. Increased sedation risk
  11. Oral Contraceptive (OCP)
    1. Reduced efficacy (use OCP with at least 35 mcg Ethinyl Estradiol)
  12. Tricyclic Antidepressants
    1. Monitor levels
  13. Immunosuppressants
    1. Monitor levels
  • Safety
  1. Avoid in Lactation
  2. Pregnancy
    1. Among preferred Protease Inhibitors in pregnant women who are HIV Treatment naive
  • Resources
  1. Atazanavir (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=165cff62-b284-4a27-a65d-9ec8a5bfcdd8
  2. Atazanavir with Cobicistat (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=83db29d7-5d85-49d6-8cb6-740473365cf8
  • References
  1. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  2. (2009) Treat Guidel Med Lett 7(78): 11-22 [PubMed]
  3. Reust (2011) Am Fam Physician 83(12): 1443-51 [PubMed]