Are we Still Treating the Numbers

A 47 year old complains that he has muscle cramps and Charley horses on his calves, which he has had for 6 weeks. He believed that his muscle cramp was due to low potassium. Upon further investigation, he reported that his cardiologist had started a statin around the same time as the start of his symptoms. The clinical symptoms and the onset of the symptoms are consistent with statin-induced myositis. A junior family physician requested a battery of laboratory works, which included serum potassium, calcium, phosphate, creatinine kinase and liver functions test. Regardless of the laboratory result, in the absence of other causes in the history, the statin is the most likely culprit and should be discontinued. In the presence of normal creatinine kinase, the statin still would require a trial of discontinuation. Although the result might be confirmatory and interesting, the test has contributed nothing to the decision.