Another N-of-1 Trial on Muscle Side Effects of Statins

In n-of-1 clinical trials to determine whether perceived drug side effects are truly drug related, participants receive several courses of an active drug or placebo in random order. This design was used recently in a small study of statin side effects (NEJM JW Cardiol Jan 2021 and N Engl J Med 2020; 383:2182).

Now, researchers have published a larger n-of-1 trial, involving 200 patients who had reported muscle symptoms while taking statins; people with histories of statin intolerance associated with creatine kinase levels ≥5 times the upper limit of normal were excluded. Each patient received three 2-month treatment periods with atorvastatin (20 mg) and three 2-month periods with placebo, randomly ordered over 1 year. Patients reported muscl…