Colchicine-Induced Neuromyopathy with Myotonic Discharges in a Patient Using Concomitant Diuretics

Abstract

Colchicine is a widely used anti-inflammatory medication, but its neuromuscular adverse effects are under-recognized. One month ago, a 70-year-old woman presented to our clinic for an evaluation of general weakness. She had been taking colchicine and diuretics daily. The weakness, which began in both thighs and lower legs approximately 4 weeks before her visit, had progressively worsened. The patient also experienced mild paresthesia and hypoesthesia in both arms and legs. Her serum creatine kinase and aldolase levels were elevated, and nerve conduction studies indicated a motor-dominant sensorimotor polyneuropathy of the axonal type. Needle electromyography showed prominent fibrillation potentials, positive sharp waves, and myotonic discharges. Suspecting colchicine-induced neuromyopathy, we discontinued the colchicine and diuretics, after which her symptoms resolved.