[Chronic human colchicine myopathy].

We report a case of myopathy induced by daily administration of colchicine. A 65-year-old man with gout and renal dysfunction had taken 1 mg of colchicine daily for 3 years. The dose was raised to 2 mg per day and two months later, he developed progressive weakness of the proximal limbs and had difficulty in rising from squatting and climbing stairs. Five months after the development of weakness, neurological examination showed proximal muscle weakness without wasting, generalized hyporeflexia and mild sensory loss and dysesthesia of the toes. Serum creatine kinase level was elevated to 788 IU/L and creatinine level was 2.1 mg/dl. Electromyography demonstrated myogenic changes with spontaneous activity. HE preparations of biceps muscle biopsy showed mild increase of variation in fiber size, small vacuoles with and without basophilic rims in some fibers and a few fibers with unevenly stained sarcoplasm. NADH-TR preparations showed numerous moth-eaten and targetoid fibers. The small rimmed vacuoles stained positively for acid phosphatase. Electron microscopy showed accumulation of lysosomes and autophagic vacuoles, and architectural changes and disruptions of myofibrils. After the discontinuation of colchicine, his strength and serum CK level normalized within two masquerading as polymyositis, may occur when customary doses of colchicine are given daily to patients with renal dysfunction.