Rifabutin (Rfb)

Update: January 2022

Forms and strengths

• 150 mg capsule

Dosage

• Child and adult: 5 to 10 mg/kg once daily
• Maximum dose: 300 mg daily

Contra-indications, adverse effects, precautions

• Do not administer to patients with hypersensitivity reaction or severe haematologic disorders (thrombocytopenia, purpura) during a previous treatment with a rifamycin.
• Administer with caution to patients with severe renal impairment or hepatic or haematologic disorders.
• May cause:
  • gastrointestinal disturbances, hepatotoxicity;
  • haematologic disorders (leukopenia, anaemia, thrombocytopenia), hypersensitivity reactions;
  • reversible uveitis.
• For the management of adverse effects, see Appendix 17.
• Reduce the dose of rifabutin:
  • in patients taking boosted protease inhibitors (Appendix 19);
  • if rifabutin toxicity is suspected in patients taking clarithromycin, fluconazole or itraconazole.
• Rifabutin reduces the effect of many drugs (macrolides, some antiretrovirals, some hormones, warfarin, etc.):
  • in patients taking antiretrovirals, see Appendix 19;
  • in women using contraception, use injectable medroxyprogesterone or an intrauterine device;
  • for the other drugs, adjust dosage if necessary.
• Pregnancy and breastfeeding: avoid (safety not established). If used in late pregnancy, administer phytomenadione (vitamin K₁) to the mother and the neonate.

Monitoring

• Symptomatic monitoring.
• Liver function in patients with hepatic disease.
• Full blood count. 

Patient instructions

• Take with or without food.
• Harmless orange-red discoloration of the urine, faeces, sweat, saliva, sputum, tears and other body fluids.

Storage