Increases in Creatine Kinase After Exercise in Patients Treated With HMG Co-A Reductase Inhibitors

To the Editor.— Creatine kinase (CK) elevations of at least twice normal occurredin 11% of patients during clinical trials of lovastatin (J. H. Milander, MD, personal communication, 1989), and rhabdomyolysis with renal failure has occurred with lovastatin in combination with other medications.1Physical exertion can also injure muscle. Average CK levels over 3000 U/L have been noted in runners after a 42-km marathon.2 We recently participated in a study using fluvastatin, a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor, lovastatin, and placebo. Twenty-three men and 13 women received placebo for 6 weeks followed by 6 weeks of placebo or fluvastatin. Thirty-four patients subsequently received lovastatin. Four men receiving reductase inhibitors developed elevated CK levels after exercise, suggesting that these drugs exacerbate the muscle injury associated with exertion (Table). Patient 1 (Table) began jogging and weight lifting several days before phlebotomy. Patient 2 played squash for