Major
Erythromycin × Theophylline
Macrolide antibiotic×Methylxanthine
Mechanism
Erythromycin inhibits CYP3A4 and CYP1A2. Theophylline rises 35-50%.
Symptoms
Nausea, tremor, tachycardia.
Management
Reduce theophylline by 25-50% with blood level check on days 3-5.
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.