Does Erythromycin Interact With Lipitor?
In our latest question and answer, our pharmacist discusses the interaction between Lipitor (atorvastatin) and erythromycin.
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.
Sep 23, 2022- Yes, there is a significant interaction between Lipitor and erythromycin that increases the risk of side effects including muscle pain and the serious condition rhabdomyolysis. Your doctor may have you skip your Lipitor dose while taking erythromycin or may prescribe a different antibiotic instead. Always confirm with your doctor what to do if you've been prescribed both medications, especially if different doctors prescribed them.
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 & sources
Glossary — Terms in This Answer
- CYP3A4
- An enzyme in the liver that breaks down many medications, including atorvastatin.
- Metabolized
- The process by which the body breaks down a drug into substances it can use or eliminate.
- CYP3A4 inhibitors
- Substances that slow down or block the enzyme that normally breaks down certain drugs, causing them to build up in the body.
- Plasma concentrations
- The amount of a drug present in the liquid part of the blood.
- Rhabdomyolysis
- A serious condition where muscle tissue breaks down rapidly and releases harmful contents into the bloodstream.
- Statin
- A class of medications used to lower cholesterol levels in the blood.
- Antibiotic
- A medication used to kill bacteria or stop bacterial growth and treat infections.
- Drug exposure
- The amount of time and concentration that a drug remains active in the body.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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