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.