CriticalMacrolide antibiotic×HMG-CoA reductase inhibitors (statins)
Updated · Methodology
Mechanism
Erythromycin inhibits CYP3A4. Simvastatin is a sensitive substrate; its concentration rises 6-fold. High rate of rhabdomyolysis with fatal cases reported. FDA Zocor Section 4.3 – strict contraindication.
Symptoms
Muscle pain, weakness, dark urine within 7 days. Labs show sharp rise in creatine kinase and creatinine.
Management
Combination contraindicated. Hold simvastatin during erythromycin therapy. Alternative: pravastatin or rosuvastatin – neither is metabolised via CYP3A4.
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.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Zocor (simvastatin) prescribing information (2012)
- AEMPS: Ficha técnica: Eritromicina (nº registro 79380), sección 4.3 (2025)– AEMPS, CIMA, nº registro 79380, sección 4.3
- AEMPS: Ficha técnica: Simvastatina (nº registro 65199), sección 4.3 (2026)– AEMPS, CIMA, nº registro 65199, revisión 03/2026, sección 4.3