Colchicine in the treatment of Paget disease of bone: a new therapeutic approach.

Paget disease of the bone (PDB) has been treated effectively with various agents including calcitonins, diphosphonates, and mithramycin. Each agent has relatively serious toxic side effects or practical inconveniences associated with its use. An effective agent with fewer adverse reactions and a more convenient route of administration would be preferable. The purpose of this study was to evaluate the effect of colchicine for the treatment of PDB in five patients. All patients were symptomatic and had typical changes on roentgenograms and bone scans consistent with the disease. Serum alkaline phosphatase ranged from 408 to 1,311 mU/ml (normal, 30 to 115 mU/ml), and urinary excretion of total hydroxyproline ranged from 68 to 205 mg/24 hr (normal, 30 to 65 mg/24 hr). Colchicine, 0.6 mg, was given orally three times a day to each patient, who had subsequent follow-up with clinical and laboratory determinations evaluated at each visit. The duration of follow-up was eight to 28 weeks, with a mean of 20 weeks. Pain was relieved in all patients, and two became asymptomatic. Serum alkaline phosphatase decreased 18% to 38%, and urinary hydroxyproline decreased 26% to 53% from the pretreatment values. The biochemical values and and clinical symptoms changed markedly in two patients, correlating with withdrawal and reinstitution of colchicine. These results indicate that colchicine may be effective in the treatment of PDB. Although the mode of action and long-term efficacy of colchicine in this disorder remains to be evaluated, the antimitotic effect on osteoprogenitor cells, the adherence of colchicine to the microtubular structures in preexisting osteoblasts, and the nonspecific anti-inflammatory effect of this agent may explain the therapeutic response noted in this study.