Lovastatin with Erythromycin Interaction Details

Brand Names Associated with Lovastatin

Brand Names Associated with Erythromycin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 15, 2023

Interaction Effect

Increased plasma level of lovastatin and a risk of myopathy or rhabdomyolysis

Interaction Summary

Concomitant use of erythromycin and lovastatin is contraindicated. Rhabdomyolysis with and without renal impairment has been reported in patients receiving concurrent therapy with erythromycin and lovastatin . Erythromycin is a known inhibitor of the cytochrome P450 3A4 enzyme system, and lovastatin is a substrate for this enzyme . Concurrent administration of erythromycin and lovastatin may result in increased plasma levels of lovastatin, thereby increasing the risk of myopathy and rhabdomyolysis. If coadministration is unavoidable, therapy with lovastatin should be suspended during the course of erythromycin treatment .

Severity

Contraindicated

Onset

Delayed

Evidence

Probable

How To Manage Interaction

Concomitant use of erythromycin and lovastatin is contraindicated due to the potential for serious reactions such as myopathy and rhabdomyolysis. If coadministration is unavoidable, therapy with lovastatin should be suspended during the course of erythromycin treatment .

Mechanism Of Interaction

Inhibition of cytochrome P450-mediated metabolism of lovastatin by erythromycin

Literature Reports

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 .

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 .

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.

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 .

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 .

Lovastatin Overview

• Lovastatin is used together with diet, weight-loss, and exercise to reduce the risk of heart attack and stroke and to decrease the chance that heart surgery will be needed in people who have heart disease or who are at risk of developing heart disease. Lovastatin is also used to decrease the amount of cholesterol (a fat-like substance) and other fatty substances in the blood. Lovastatin is in a class of medications called HMG CoA reductase inhibitors (statins). It works by slowing the production of cholesterol in the body to decrease the amount of cholesterol that may build up on the walls of the arteries and block blood flow to the heart, brain, and other parts of the body.

• Accumulation of cholesterol and fats along the walls of your arteries (a process known as atherosclerosis) decreases blood flow and, therefore, the oxygen supply to your heart, brain, and other parts of your body. Lowering your blood level of cholesterol and fats with lovastatin may help prevent heart disease, angina (chest pain), strokes, and heart attacks.

Erythromycin Overview

• Erythromycin is used to treat certain infections caused by bacteria, such as infections of the respiratory tract, including bronchitis, pneumonia, Legionnaires' disease (a type of lung infection), and pertussis (whooping cough; a serious infection that can cause severe coughing); diphtheria (a serious infection in the throat); sexually transmitted diseases (STD), including syphilis; and ear, intestine, gynecological, urinary tract, and skin infections. It also is used to prevent recurrent rheumatic fever. Erythromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria.

• Antibiotics such as erythromycin will not work for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.

Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.

Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.

Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.