Clinical, biochemical and histological observations on the effect of porcine calcitonin in Paget's disease of bone.

The response to porcine calcitonin has been assessed in 38 patients with Paget's disease, observed during 44 treatment periods of from three to 42 months. In 36 of the treatment courses significant relief of pain was achieved but the contribution of placebo effect could not be determined. Serum alkaline phosphatase and urinary hydroxyproline levels reached normal in a few patients, but the grouped data indicated a plateau effect above the range of normal. The acute hypocalcaemic response to calcitonin was lost only in those patients whose bone turnover was restored to normal. Quantitative histology on iliac crest bone biopsy samples showed no statisically significant lowering of osteoclast counts. No antibody-based clinical resistance occurred and the incidence of side effects was low. The results indicate that porcine calcitonin is a useful treatment of Paget's disease, and the experience of the study helps in arriving at patient selection and treatment schedules. Treatment is recommended for bone pain and for active disease in the relatively young, using intermittent therapy with course of at least six months duration. Resumption of therapy is based on clinical and biochemical indications.