rifabutin: clinical use

Prescribing considerations

• Use under specialist management with susceptibility, resistance and interaction considerations addressed.
• Use with other active non-rifamycin antimycobacterials when treating established mycobacterial infection.
• Exclude active tuberculosis or other mycobacterial disease before starting MAC prophylaxis.
• Undertake detailed reconciliation of antiretrovirals, hepatitis C treatments, antifungals, immunosuppressants and contraception.
• Data supporting use in children are inadequate.
• Exercise caution in severe hepatic impairment and account for severe renal impairment.

Contraindications and cautions

• Hypersensitivity to rifabutin, another rifamycin or a formulation excipient.
• Concomitant cabotegravir–rilpivirine prolonged-release injectable treatment.
• Pregnancy or breastfeeding under the selected product information because clinical experience is insufficient.

Monitoring

• White blood cell count, platelet count and liver enzymes periodically.
• New eye pain, redness, photophobia or visual change; risk is increased with macrolides or azole antifungals.
• Skin rash for progression or systemic features of a severe cutaneous reaction.
• Clinical, microbiological and virological response where interacting anti-infectives are used.

Clinical pharmacology

A rifamycin that inhibits bacterial DNA-dependent RNA polymerase. Rifabutin penetrates cells and lung tissue, is metabolised partly through CYP3A pathways, induces CYP3A and is eliminated mainly in urine as parent medicine and metabolites.

Formulation and product differences

• The selected product is an opaque red-brown hard gelatin capsule supplied in blisters.
• The formulation is essentially sodium-free.
• No liquid or injectable rifabutin formulation is represented by the selected product.

Capsule

Route: Oral

Strengths: 150 mg