What the FDA labels say about taking them together
Erythromycin and simvastatin
Erythromycin's FDA label of August 1, 2024 names simvastatin in its contraindications section, and simvastatin's label names erythromycin too. The simvastatin label: “Simvastatin is a substrate of CYP3A4. Concomitant use of strong CYP3A4 inhibitors with ZOCOR increases simvastatin exposure and increases the risk of myopathy and rhabdomyolysis, particularly with higher ZOCOR dosages.”
Check it at the source: the erythromycin FDA label on DailyMed (effective August 1, 2024, Teva Pharmaceuticals USA, Inc.); the simvastatin FDA label on DailyMed (effective March 28, 2025, Organon LLC).
What does the erythromycin label say about simvastatin?
Erythromycin label, contraindicationsDo not use erythromycin concomitantly with HMG CoA reductase inhibitors (statins) that are extensively metabolized by CYP 3A4 (lovastatin or simvastatin), due to the increased risk of myopathy, including rhabdomyolysis.
Erythromycin label, drug interactionsHMG-CoA Reductase Inhibitors Erythromycin has been reported to increase concentrations of HMG-CoA reductase inhibitors (e.g., lovastatin and simvastatin).
Erythromycin label, warningsThese include colchicine toxicity with colchicine; rhabdomyolysis with simvastatin, lovastatin, and atorvastatin; and hypotension with calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, amlodipine, diltiazem) (see PRECAUTIONS - Drug Interactions ).
Ery-Ped label (Azurity Pharmaceuticals, Inc. (formerly Arbor Pharmaceuticals), December 16, 2023), contraindicationsErythromycin is contraindicated in patients taking terfenadine, astemizole, pimozide, or cisapride. (See PRECAUTIONS - Drug Interactions .) Do not use erythromycin concomitantly with HMG CoA reductase inhibitors (statins) that are extensively metabolized by CYP 3A4 (lovastatin or simvastatin), due to the increased risk of myopathy, including rhabdomyolysis.
Source: FDA drug label (Erythrocin Lactobionate, NDA050609), Hospira, Inc., effective October 30, 2025 (SPL set a96c405f-bd70-4bb4-719e-ac6a79dcc213), via openFDA
Source: FDA drug label (Erythromycin), Teva Pharmaceuticals USA, Inc., effective August 1, 2024 (SPL set 75a0bd5a-d09f-483b-bfd8-f8343b149eb2), via openFDA; the full label on DailyMed
What does the simvastatin label say about erythromycin?
Simvastatin label, drug interactionsStrong CYP3A4 inhibitors Clinical Impact: Simvastatin is a substrate of CYP3A4. Concomitant use of strong CYP3A4 inhibitors with ZOCOR increases simvastatin exposure and increases the risk of myopathy and rhabdomyolysis, particularly with higher ZOCOR dosages. … (e.g., itraconazole, ketoconazole, posaconazole, and voriconazole), select macrolide antibiotics (e.g., erythromycin and clarithromycin), select HIV protease inhibitors (e.g., nelfinavir, ritonavir, and darunavir/ritonavir), select HCV protease inhibitors (e.g., boceprevir and telaprevir) …
Source: FDA drug label (ZOCOR), Organon LLC, effective March 28, 2025 (SPL set 8f55d5de-5a4f-4a39-8c84-c53976dd6af9), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Erythromycin | Simvastatin | |
|---|---|---|
| Labeled for | Bacterial infections, Acne | Heart attack and coronary artery disease, High cholesterol, High triglycerides |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.96 per tablet 250 mg tablet | $0.0321 per tablet 20 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once