Craig I. Coleman, PharmD, and Malek Mediouni, PharmD Candidate
Case One
Coenzyme Q10 and Statin-Induced Myalgia
LG, a 45-year-old woman, arrives at the pharmacy counter with a prescription for simvastatin 40 mg once daily. She explains that her doctor just prescribed this medication to her to lower her cholesterol. She then inquires about coenzyme Q10, stating, “My friend who also takes simvastatin suggested I take this to prevent muscle pain.” LG takes no other prescription or OTC medications.
How might the pharmacist advise LG?
Case Two
Probiotics
GL, a 23-year-old man, comes to your pharmacy with a prescription for amoxicillin 500 mg 3 times daily. He explains to the pharmacist that his doctor prescribed the antibiotic to treat a respiratory infection. GL then inquires about probiotics, stating, “My doctor told me I should consider taking this to prevent diarrhea.”
What advice might you have for GL?
ANSWERS
Case 1: Statins are first-line agents for lowering low-density lipoprotein cholesterol levels. As part of their mechanism of action, they inhibit the production of mevolanate, a precursor to the production of both cholesterol and coenzyme Q10 (also known as ubiquinone). Reduced levels of coenzyme Q10 in muscle tissue can result in disruption of mitochondrial processes, and consequently may explain the muscle pain (myalgia) associated with statin use. The pharmacist should first inform LG that only a small proportion of patients taking simvastatin—less than 4%—will experience myalgia. Further, LG should be counseled that much of the evi dence supporting coenzyme Q10’s effect on statin myalgia comes from prescriber and patient selfreport. Of note, 1 small randomized trial of 32 patients did suggest coenzyme Q10 could reduce statin-related muscle pain; however, other studies have shown contradictory results. Because coenzyme Q10 is generally regarded as safe and LG does not take any medications that could result in drug interactions (eg, warfarin, timolol eye drops), it is likely that little harm will come from her taking a coenzyme Q10 supplement. If the patient opts to take coenzyme Q10, the dose recommended for statin myalgia is 100 mg daily. As many manufacturers sell coenzyme Q10 supplements, the pharmacist should recommend the patient choose a product that carries the Verified Dietary Supplement Mark on its label to assure high quality.
Case 2: Antimicrobial-associated diarrhea (AAD) is one of the most common side effects of antimicrobial therapy. The bacteria that reside in our gastrointestinal tract play many key roles in maintaining healthy digestion, including (1) protection from pathogenic bacteria, (2) the production of many vitamins, and (3) the breakdown of otherwise nonabsorbable foods. These vital functions are often lost with the elimination of enteric bacteria secondary to antibiotic therapy, resulting in AAD. Lactic acid bacteria and bifidobacteria are the most common constituents of probiotics. The pharmacist should explain to GL that probiotics have been shown to reduce the incidence and - severity of AAD; however, further documentation of these findings through higher-quality medi cal research is warranted. The constituents (multiple components may be more efficacious than a - single), dosing (the duration of therapy often parallels the antibiotic therapy), and storage of probi otics differs among products; therefore, the pharmacist should refer to the package insert of each product for more information.
Dr. Coleman is associate professor of pharmacy practice and director of the pharmacoeconomics and outcomes studies group at the University of Connecticut School of Pharmacy. Mr. Mediouni is a PharmD candidate at the University of Connecticut School of Pharmacy.
