Erythromycin and Simvastatin interaction
Erythromycin and Simvastatin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Erythromycin label · effective 2025-09-25
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 (see PRECAUTIONS - Drug Interactions ).
These include colchicine toxicity with colchicine; rhabdomyolysis with simvastatin, lovastatin, and atorvastatin; and hypotension with calcium channel blockers metabolized by CYP3A4 (for example, verapamil, amlodipine, diltiazem) (see PRECAUTIONS, Drug Interactions ).
HMG-CoA Reductase Inhibitors Erythromycin has been reported to increase concentrations of HMG-CoA reductase inhibitors (for example, lovastatin and simvastatin).
From the Simvastatin (ZOCOR) label · effective 2025-03-28
ZOCOR is contraindicated in the following conditions: Concomitant use of strong CYP3A4 inhibitors (select azole anti-fungals, macrolide antibiotics, anti-viral medications, and nefazodone) [see Drug Interactions (7.1) ] .
Concomitant use of strong CYP3A4 inhibitors (select azole anti-fungals, macrolide antibiotics, anti-viral medications, and nefazodone) ( 4 , 7.1 )
Steps to Prevent or Reduce the Risk of Myopathy and Rhabdomyolysis The concomitant use of strong CYP3A4 inhibitors with ZOCOR is contraindicated.
Intervention: Concomitant use of strong CYP3A4 inhibitors with ZOCOR is contraindicated [see Contraindications (4) ] .
If treatment with a CYP3A4 inhibitor is unavoidable, suspend ZOCOR during the course of strong CYP3A4 inhibitor treatment.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.