Critical
Atorvastatin × Clarithromycin
HMG-CoA reductase inhibitors (statins)×Macrolide antibiotic
Mechanism
Clarithromycin is a strong CYP3A4 and P-glycoprotein inhibitor. Atorvastatin plasma concentration rises 4–5 fold, increasing risk of rhabdomyolysis with acute kidney injury. FDA caps atorvastatin at 20 mg/day during co-administration; EMA recommends temporary statin withdrawal.
Symptoms
Within 5–10 days: muscle pain, especially thighs and shoulder girdle, dark urine, creatine kinase above 10× ULN, rising creatinine.
Management
Hold or reduce atorvastatin to 10–20 mg/day for the duration of clarithromycin (typically 7–14 days). Alternative: switch clarithromycin to azithromycin, which lacks CYP3A4 inhibition.
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.