[Intermittent treatment of Paget's disease of bone with calcitonin: histological study]

The authors report the results of a semi-quantitative histological study of bone carried out in 6 patients with Paget's disease treated with salmon calcitonin (about thirty injections of an average of 50 MRC units) over 8 to 14 weeks. The treatment led to a decrease in the resorption surfaces, in the number and the nucleation of the osteoclasts, and in the level of hydroxyprolinuria. Cessation of treatment led to an increase in these parameters, but starting from the fifth month after the cessation renewed improvement was noted, concerning in particular the hydroxyprolinuria and the nucleation of the osteoclasts and this lasted until the tenth month. The possibility of a prolonged action of calcitonin indicates that discontinuous therapy of Paget's disease should be considered (4 months per year, for example).