Today in the NEJM

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This was in the New England Journal of Medicine today.

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3. Statin-Induced MyopathyORIGINAL ARTICLE, SLCO1B1 Variants and Statin-Induced Myopathy — A Genomewide Study, The SEARCH Collaborative Group, Abstract | Full Text | PDF | PPT Slide SetEDITORIAL, Pharmacogenomics and Drug Toxicity, Y. Nakamura, Extract | Full Text | PDFA genomewide screen of patients with myopathy who were taking high-dose simvastatin (80 mg per day) showed a strong association between myopathy and variants of SLCO1B1. Approximately 60% of the cases of myopathy was associated with these variants. Genotyping SLCO1B1 variants may be helpful for tailoring the dosage of statins and safety monitoring.Figure

2. Odds Ratios for Myopathy Associated with the SLCO1B1 rs4149056 Genotype among Subgroups of Patients Taking 80 mg of Simvastatin Daily.

topClinical Pearls Statin-Induced MyopathyIn rare cases, statins can cause muscle pain or weakness in association with elevated creatine kinase levels (i.e., myopathy), and, occasionally, this leads to muscle breakdown and myoglobin release (i.e., rhabdomyolysis), which confers a risk of renal failure and death. The mechanisms by which statins cause myopathy remain unknown but appear to be related to statin concentration in the blood. The incidence of frank myopathy is typically only about 1 case in 10,000 patients per year with standard doses (e.g., 20 to 40 mg of simvastatin daily) but it increases with higher doses (e.g., 80 mg of simvastatin daily) and with concomitant use of certain drugs (e.g., cyclosporine which can inhibit statin metabolism).Table 1. Relative Risk of Myopathy Associated with Selected Baseline Characteristics among 6031 Participants Assigned to 80 mg of Simvastatin Daily in SEARCH. Increased Risk for Statin-Induced MyopathyThis study by The SEARCH Collaborative Group, reports small increases in the risk of myopathy among older participants and women, as well as among those with evidence of impaired renal function and those who were taking calcium antagonists at baseline.

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Morning Report Question

Q:

What cardiac drug increases the risk that a statin will cause myopathy?

A:

Amiodarone can increase the risk that a statin will cause myopathy, for example when amiodarone is taken with 80 mg of simvastatin daily the risk of statin-induced myopathy increases significantly.