Does Erythromycin Interact With Lipitor?

In our latest question and answer, our pharmacist discusses the interaction between Lipitor (atorvastatin) and erythromycin.

Question

Hi, I take Lipitor every day for cholesterol. I was recently put on erythromycin for an infection I have. I just want to be sure they are ok to take together.

Asked by Marie On Sep 23, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Sep 23, 2022
Last updated Sep 23, 2022

Key points

  • Taking erythromycin and atorvastatin together can increase the risk of atorvastatin-related side effects, such as muscle pain/weakness.
  • Although these drugs are sometimes used together, combined use is generally avoided.
  • Ask your doctor about how you should proceed with your therapy. They may ask you to 'hold' your atorvastatin while on erythromycin therapy, or prescribe you a different antibiotic.

Answer

There is an interaction between Lipitor (atorvastatin) and erythromycin. The combination is generally avoided due to the increased risk of side effects, including the rare, but serious side effect of rhabdomyolysis.

Nevertheless, there may be cases where both can be used together if it represents the best therapy. Be sure to talk to your doctor if you have been prescribed both.

Interaction Details

Lipitor (atorvastatin) is primarily metabolized via CYP3A4 in the liver, and coadministration with CYP3A4 inhibitors, such as erythromycin, may lead to increased plasma concentrations of atorvastatin and drug exposure.

Clinical studies have found that co-administration of Lipitor and erythromycin resulted in a 38% increase in maximum blood concentration of atorvastatin. This increases the risk of side effects, such as muscle pain, fatigue, and, perhaps most seriously, rhabdomyolysis.

Other studies have found that compared to another antibiotic (azithromycin), the combined use of a statin (atorvastatin, simvastatin, or lovastatin) with erythromycin was associated with a higher risk of hospitalization.

What To Do

Although there certainly is an interaction here, these drugs are sometimes used together since erythromycin is generally used for only a short time period. However, in some cases, your doctor may tell you to 'hold' atorvastatin until you finish erythromycin therapy. Alternatively, a different antibiotic may be used if you take Lipitor to avoid the interaction altogether.

If you have been prescribed both drugs, especially by different doctors, be sure to reach out and see what they direct you to do. I generally see individuals either hold off taking Lipitor while taking erythromycin or the doctor prescribing a different antibiotic.

Final Words

Thanks for reaching out to us! We're always more than happy to help.

References

  • Statin toxicity from macrolide antibiotic coprescription: a population-based cohort study, PubMed
  • Erythromycin Monograph, PubChem
  • Atorvastatin Monograph, PubChem

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 11 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Feel free to send him an email at Hello@HelloPharmacist.com! You can also connect with Dr. Brian Staiger on LinkedIn.

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