[Toxic myopathy with kidney failure as a colchicine side effect ifn familial Mediterranean fever]

A 24-year-old woman with familial Mediterranean fever (FMF) had for one year been treated with colchicine, 1 mg daily, for repeated bouts of fever, abdominal pain and arthritis. She was also known to have renal amyloidosis. Lately she had developed gastrointestinal symptoms, muscle pain and obvious, predominantly proximal muscular weakness in both legs. The cause of the symptoms was rhabdomyolysis with an increased creatinine activity of 1000 U/l and marked myoglobinuria (1600 micrograms/l), as well as renal failure with normal uric acid and a creatinine clearance of 3 ml/min per 1.73 m2. Serum creatinine concentration was 970 mumol/l, urea 34 mmol/l. Muscle biopsy corresponded to a subacute necrotizing myopathy with vacuole formation, signs typical of toxic damage. Renal biopsy confirmed advanced amyloidosis. The colchicine dose was reduced to 0.5 mg/d. The renal failure responded to conservative treatment. The myopathy symptoms receded within 4 weeks, creatinine clearance rising to 25 ml/min per 1.73 m2. 12 months after reduction of the colchicine dose the patient was without any FMF-related symptoms.