Future horizons for calcitonin: a U.S. perspective.

Injectable salmon calcitonin has been in use in the United States for more than a decade for the treatment of patients with postmenopausal osteoporosis, Paget's disease, and hypercalcemia. Sandoz Pharmaceuticals Corp. is currently in the process of developing a nasal formulation of salmon calcitonin. Studies are in progress to compare the efficacy of this nasal formulation with that of the injectable hormone in preventing bone loss and restoring bone, as well as in reducing pain associated with bone diseases. The rationale for development of a nasal formulation is to attempt to reduce the incidence of systemic side effects, inconvenience, and resulting noncompliance associated with the injectable product. In studies to date, the nasal form of calcitonin has been well tolerated by most subjects and was not notably associated with nasal irritation. The tolerability seen within the context of clinical trials suggests that a nasal formulation might be well accepted, even among asymptomatic osteoporotic patients. Asymptomatic patients with secondary osteoporosis due to steroid administration or solid organ transplantation may also be studied as possible candidates for the prophylactic use of this drug. Additional future research includes the development of an oral calcitonin agent.