To the Editor In their commentary on generic drug use, Alldredge and Kayser1(p233) state the following:That statement is an unfair criticism of physicians and conflicts with the expressed views of the Food and Drug Administration (FDA). On June 8, 2011, the FDA issued a safety warning concerning simvastatin2 in which physicians were advised to discontinue the use of simvastatin, 80 mg (except in patients who had already been taking it safely for over 1 year). For patients taking amlodipine, the FDA warned against prescribing more than 20 mg of simvastatin, and for patients taking diltiazem or verapamil, the dose of simvastatin was limited to 10 mg. These safety warnings were based on reports of adverse events including serious myopathy caused by simvastatin, 80 mg, and by lower doses of simvastatin when combined with widely prescribed calcium channel blockers. As a result, physicians were left with a maximum safe simvastatin dose of 40 mg, which lowers low-density lipoprotein cholesterol level by approximately 40%, whereas atorvastatin, 80 mg, lowers low-density lipoprotein cholesterol level by approximately 55%.3 The FDA has not deemed it necessary to issue similar safety restrictions on the use of atorvastatin, which may explain why physicians favored Lipitor over generic simvastatin in 2011.
Keller DL. Why Physicians Favored Lipitor Over Simvastatin. JAMA Intern Med. 2013;173(15):1473. doi:10.1001/jamainternmed.2013.7747