[Clinical efficacy of treatment with salmon calcitonin, administered intranasally for 1 year, in stabilized postmenopausal osteoporosis].

Several controlled clinical studies have confirmed the rationale of calcitonin therapy in postmenopausal osteoporosis. However, administration by injection and side-effects reduced patient compliance and flexibility of dosage. Recently, evidence has been given that an intranasal spray may provide an effective alternative administration route for calcitonin. Forty women with established postmenopausal osteoporosis (at least on vertebral crush fracture) divided into three groups, entered and completed a one-year controlled study on the effects of treatment with synthetic salmon calcitonin nasal spray on bone mass and mineral metabolism. The first group (n = 20) received a daily treatment with 100 I.U. of salmon calcitonin (sCT) nasal spray; the second group (n = 10) received 100 I.U. of sCT by subcutaneous injection every second day; the control group (n = 10) received an oral calcium supplement, 1 g per day. Bone mineral content (BMC), evaluated by dual photon absorptiometry, was measured at the distal radius before and after 6 and 12 months of treatment. Every three months, throughout the year, an evaluation of some parameters of bone remodeling was made. BMC increased (p less than 0.01) in the treatment groups, whereas at the end of treatment, a decrease (p less than 0.05) was observed in the control group. Biochemical estimates of bone resorption, such as urinary hydroxyproline excretion showed a significant decrease in the calcitonin groups. No changes in markers of bone formation, serum alkaline phosphatase and osteocalcin were observed in all patients. This study demonstrates that one-year treatment with sCT nasal spray is able to increase bone mass in osteoporotic patients without important local side-effects.