Calcitonin for Osteoporosis?

Several patients have recently asked me about the medication calcitonin for the treatment of osteoporosis. Calcitonin is a hormone secreted by the thyroid gland and helps direct blood calcium into bone. Salmon calcitonin nasal sprays (Fortical, Miacalcin) were some of the first medications developed to treat osteoporosis. But do they work and are they safe? As far as its effectiveness is concerned, calcitonin does seem to have a moderate but limited benefit (it often looses its effectiveness after about 2 years) for reducing vertebral, but not hip, fractures. 

Nasal calcitonin has often been used either for patients who cannot tolerate bisphosphonate therapy or for those experiencing pain from an osteoporosis-related fracture. Several studies have shown that it can reduce back pain caused by compression fractures. In a September 24, 2010 clinical practice guideline, the American Academy of Orthopaedic Surgeons recommended "patients who present with an osteoporotic spinal compression fracture on imaging with correlating clinical signs and symptoms suggesting an acute injury (0-5 days after identifiable event or onset of symptoms) and who are neurologically intact be treated with calcitonin for 4 weeks."

Calcitonin was always considered fairly safe until recently. In July, 2012 the European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP) concluded that after reviewing the safety/benefit of calcitonin there was evidence linking it to increased cancer risk. "Although the cancer rates reported in the studies were low, the increase in cancer rates seen with calcitonin varied between 0.7% in the studies with the oral formulation to 2.4% in the studies with the nasal formulation. Taking into account the limited benefit of calcitonin when used to treat post-menopausal osteoporosis to reduce the risk of vertebral fractures, the CHMP concluded that the benefits of calcitonin did not outweigh the risks in this condition. As the nasal spray is only used in osteoporosis, the CHMP recommended that this formulation should no longer be used." As a result of this review, both Fortical and Miacalcin were withdrawn from the market in August, 2012.

Time and time again, whether it be from the disturbing news of the 2002 Women's Health Initiative study, which determined that the risks of HRT outweighed its benefits, or the rising number of cases of osteonecrosis of the jaw and atypical femur fractures from bisphosphonate therapy, or the recent delay by Merck (citing safety concerns) to apply for early approval of their next new wonder drug, odanacatib, for the treatment of osteoporosis, one thing I have learned in my journey with osteoporosis is that diet, quality supplements and exercise--not medications--are the key to improved bone health.