II. Indications

  1. Prophylaxis of Mycobacterium Avium Complex Infection in AIDS
  2. Treatment of Mycobacterium Avium Complex Infection in AIDS
    1. See other references for multi-drug treatment regimens that include Rifabutin

III. Mechanism

  1. Semisynthetic Rifamycin derivative active against Mycobacteria
    1. Rifamycin is produced by Streptomyces mediterranei
  2. Rifamycins inhibit Bacterial DNA-dependent RNA Polymerase, blocking Bacterial RNA formation and transcription
    1. Increased activity against Mycobacterium Avium Complex compared with other Rifamycins

IV. Dosing: Prophylaxis Mycobacterium Avium Complex Infection in AIDS

  1. Adult (and age >6 years)
    1. Take 300 mg orally daily OR
    2. Take 150 mg orally twice daily (if gi irritation with 300 mg dose)
  2. Child (age < 6 years, off label)
    1. Give 5 mg/kg (up to 300 mg) orally daily
  3. Indications to decrease dosing (e.g. 50% reduction)
    1. Hepatic dysfunction
    2. eGFR <30 ml/min
    3. Toxicity suspected

V. Safety

  1. Pregnancy Category B
  2. Considered safe in Lactation

VI. Adverse Effects

  1. Uveitis
    1. Risk increases with higher dose
  2. Hepatotoxicity
  3. Thrombocytopenia
  4. Neutropenia
  5. Skin Hyperpigmentation
  6. Body fluid discoloration (orange or brown)
    1. Urine
    2. Sweat
    3. Contact Lenses

VII. Monitoring

  1. Baseline
    1. Complete Blood Count with Platelets
    2. Liver Function Tests (LFTs)
  2. Periodic lab monitoring indications
    1. Abnormal baseline Liver Function Test
    2. History suggestive of Possible liver disorder or Chronic Liver Disease
    3. Human Immunodeficiency Virus (HIV)
    4. Pregnancy

VIII. Drug Interactions

  1. CYP3A4 Inducer and CYP3A4 Substrate
    1. Oral Contraceptives (decreased efficacy)
    2. Imidazole Antifungal
    3. Clarithromycin

X. References

  1. (2012) Med Lett Drugs Ther 10(116): 29-36

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Cost: Medications

rifabutin (on 5/17/2023 at Medicaid.Gov Survey of pharmacy drug pricing)
RIFABUTIN 150 MG CAPSULE Generic $10.76 each