A case of colchicine myopathy in which the long-term use of colchicine hampered the recovery

A 69-year-old woman was admitted to our hospital because of limb weakness. She was diagnosed to have chronic renal failure due to diabetes mellitus and had suffered from pericardial effusion at 67 years of age. She started taking colchicine 18 months before admission and thereafter gradually developed muscle weakness in her limbs and had become bedridden at the time of admission. The withdrawal of colchicine improved her limb weakness, and therefore we diagnosed her to have colchicine myopathy. Her muscle strength did not completely recover even after six months from cessation of colchicine. It was suggested that renal failure and muscle disuse had prevented the full recovery of her muscles in addition to the long-term use of colchicine. Typical colchicine myopathy improves rapidly, but the long-term use of colchicine is considered to cause muscle weakness. Although the CK level was elevated, the elevated CK and myopathy had been overlooked because the CK baseline was low due to the patient's small amount of muscle mass. Moreover, the estimated GFR was recorded to be higher than her actual renal function due to her small amount of muscle mass, therefore the risk of colchicine myopathy in this case remained unrecognized.