Major
Clarithromycin × Rifabutin
Macrolide antibiotic×Antitubercular, rifamycin derivative
Mechanism
Clarithromycin inhibits CYP3A4. Rifabutin rises 2.5-fold – increased uveitis risk, especially in MAC infection patients.
Symptoms
Eye pain, photophobia, reduced vision.
Management
Reduce rifabutin to 300 mg/day (standard 450 mg). Regular ophthalmology review.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Sources
- FDA: Mycobutin (rifabutin) prescribing information (2018)– FDA Mycobutin label