Lovastatin and Erythromycin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Erythromycin
Lovastatin
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased lovastatin exposure, an increased risk of lovastatin-related adverse reaction and an increased risk of myopathy or rhabdomyolysis
Interaction Deep Dive
Concomitant use of erythromycin and lovastatin is contraindicated234. Rhabdomyolysis with and without renal impairment has been reported in patients receiving concurrent therapy with erythromycin and lovastatin 1. Erythromycin is a known inhibitor of the cytochrome P450 3A4 enzyme system, and lovastatin is a substrate for this enzyme 5, and coadministration may also increase lovastatin exposure and cause serious adverse reactions. Carefully monitor for creatine kinase and serum transaminase levels 34.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of lovastatin
Literature reports
6 reports — tap to read
a) In a retrospective, population-based cohort study of adults older than 65 years taking a statin metabolized by CYP3A (atorvastatin, 73%; simvastatin, 24%; lovastatin, 3%), concomitant administration with clarithromycin (n=72,591) or erythromycin (n=3267) was associated a rate of hospitalization for rhabdomyolysis of 0.03% and a rate of hospitalization for acute kidney injury of 0.46%. Corresponding rates with concomitant administration of azithromycin (n=68,478) were 0.01% and 0.26%, respectively. The all-cause mortality rate was 0.7% in the clarithromycin/erythromycin group and 0.45% in the azithromycin group 6.
b) A 65-year-old male with coronary artery disease and chronic renal failure was given a 13-day course of intravenous erythromycin 500 mg every six hours for three days, followed by a 10-day oral course at home for the treatment of pneumonia. He was also taking lovastatin 20 mg orally three times daily, dilTIAZem 30 mg three times daily, allopurinol 100 mg three times daily, and aspirin 325 mg daily. The patient developed progressive weakness and diffuse myalgias at the end of the erythromycin therapy; this was diagnosed later as rhabdomyolysis. The lovastatin serum level at this time was 97.6 ng equivalent/mL (8-fold greater than expected). Lovastatin withdrawal resulted in improvement over a period of one week. It is speculated that erythromycin inhibited the clearance of lovastatin, resulting in an elevated lovastatin serum level 7.
c) A 46-year-old male heart transplant patient was receiving predniSONE, cycloSPORINE, and lovastatin for more than a year. When erythromycin was added to his therapy, rhabdomyolysis was diagnosed within three weeks, but the cycloSPORINE-lovastatin combination was thought responsible for the adverse reaction 1.
d) A 68-year-old female patient with diabetes receiving lovastatin therapy developed rhabdomyolysis after a 10-day treatment regimen of erythromycin. Her serum lovastatin levels were 3-fold higher than normally expected 8.
e) A 73-year-old male stabilized on lovastatin 20 mg daily for the previous seven years presented to the emergency room with a three-day history of muscle weakness and abdominal distention. Over the previous two weeks, he had undergone extensive dental work and received prophylactic erythromycin therapy instead of penicillin against subacute bacterial endocarditis due to a penicillin allergy. He had ingested a total of 9 grams of erythromycin over two weeks, and his last dose of erythromycin had been four days prior to presentation. Laboratory values revealed pancreatitis, increased aminotransferase values, rhabdomyolysis with acute renal failure, and myoglobinuria. The patient recovered without sequelae following ten days of hospitalization 9.
f) Rhabdomyolysis with and without renal impairment has been reported in patients receiving concurrent therapy with erythromycin and lovastatin 10871234.
Common questions
Can I take Lovastatin and Erythromycin together?
Increased lovastatin exposure, an increased risk of lovastatin-related adverse reaction and an increased risk of myopathy or rhabdomyolysis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lovastatin and Erythromycin interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Lovastatin or Erythromycin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (10)
- Corpier CL, Jones PH, Suki WN, et al: Rhabdomyolysis and renal injury with lovastatin use. Report of two cases in cardiac transplant recipients. JAMA 1988; 260:239-241. DOI
- Product Information: Erythromycin Lactobionate IV injection lyophilized powder for solution, erythromycin lactobionate IV injection lyophilized powder for solution. Nexus Pharmaceuticals (per DailyMed), Lincolnshire, IL, 2024.
- Product Information: Erythromycin oral delayed-release capsules, erythromycin oral delayed-release capsules. Dr. Reddy's Laboratories Inc. (per DailyMed), Princeton, NJ, 2025. DailyMed
- Product Information: ERYTHROMYCIN ETHYLSUCCINATE oral suspension granule, erythromycin ethylsuccinate oral suspension granule. ANI Pharmaceuticals, Inc (per DailyMed), Baudette, MN, 2025. DailyMed
- Gillum JG, Israel DS, & Polk RE: Pharmacokinetic drug interactions with antimicrobial agents. Clin Pharmacokinet 1993; 25:450-482. PubMed
- Patel AM, Shariff S, Bailey DG, et al: Statin toxicity from macrolide antibiotic coprescription: a population-based cohort study. Ann Intern Med 2013; 158(12):869-876. DOI
- Ayanian JZ, Fuchs CS, & Stone RM: Lovastatin and rhabdomyolysis (letter). Ann Intern Med 1988; 109:682-683. PubMed
- Spach DH, Bauwens JE, & Clark CD: Rhabdomyolysis associated with lovastatin and erythromycin use. West J Med 1991; 154:213-215.
- Wong PWK, Dillard TA, & Kroenke K: Multiple organ toxicity from addition of erythromycin to long-term lovastatin therapy. South Med J 1998; 91:202-205. PubMed
- Product Information: Altocor(TM), lovastatin extended-release tablets. Andrx Laboratories, Inc. Weston, FL, 2003. DailyMed
Keep reading about Erythromycin
Keep reading about Lovastatin
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