Clofibrate-induced muscular syndrome. Case report with ultrastructural findings and review of the literature.

A 70-year-old man with chronic renal failure was treated with clofibrate, 2.0 g daily for 6 days, and subsequently developed clofibrate-induced muscular syndrome (CMS), i.e., myalgia with severe muscle weakness and tenderness. Elevated muscular enzyme activities were found upon examination of his blood. Electron microscopic studies revealed atrophy of some muscle fibers and massive degenerative changes. The atrophic fibers were associated with damaged neuromuscular junctions. A literature survey of 44 cases with CMS is included.