Response of Paget's disease to human calcitonin in patients resistant to porcine calcitonin.

Eleven patients with Paget's disease of bone, treated intermittently for 2-4 years with porcine calcitonin (pCT) and clinically resistant to pCT [no modifications of serum alkaline phosphatase (ALP) and urinary hydroxyproline ( uHOP ) during pCT administration] were treated with 0.5-0.25 mg/day of human calcitonin (hCT) for 3-6 months. Nine of our patients showed biochemical improvement during the first 2 months of treatment, with reduction in ALP and uHOP . In one patient with slightly increased ALP and uHOP , and in another one during the second treatment course, hCT treatment did not modify the biochemical indices of bone disease. However all patients, including those with biochemical resistance, experienced a remarkable diminution of bone pain, which had not been observed during previous pCT treatment courses. Therefore, hCT appears to be indicated for therapeutic use in patients who are resistant to foreign calcitonins.