[Current treatment concepts in primary osteoporosis: calcitonin]

The beneficial effect of calcitonin treatment on osteoporosis is generally accepted. Analgetic potency and inhibition of osteoclasts are well documented for both the injectable and the nasally applicable hormone. Preventive and therapeutic long-term application is followed by a significant increase in bone density at different axial and peripheral sites of the skeleton both in postmenopausal and in corticoid-induced osteoporosis. According to recent data these increases run parallel to a decrease in fracture incidence. When treating patients with calcitonin, different aspects must be taken into consideration, some of which need further clinical investigation. Patients with high-turnover osteoporosis generally show a better response to therapy. Data concerning the advantages and disadvantages of different calcitonins are lacking. Most clinical studies were done with salmon calcitonin. The lowest effective dosage of subcutaneously or nasally administered hormone should be further investigated. Secondary resistance after long-term use may be avoided by intermittent administration. An optimal schedule concerning treatment and free intervals has to be determined. A schedule with three months on an three months off is at present proposed by different groups. Combination with calcium can be recommended. Continuous or cyclical combinations with other drugs are under investigations.