INTERMITTENT ETIDRONATE THERAPY TO PREVENT CORTICOSTEROID-INDUCED OSTEOPOROSIS

Background and Methods Osteoporosis is a recognized complication of co rticosteroid therapy. Whether it can be prevented is not known. We con ducted a 12-month, randomized, placebo-controlled study of intermitten t etidronate (400 mg per day for 14 days) followed by calcium (500 mg per day for 76 days), given for four cycles, in 141 men and women (age , 19 to 87 years) who had recently begun high-dose corticosteroid ther apy. The primary outcome measure was the difference in the change in t he bone density of the lumbar spine between the groups from base line to week 52. Secondary measures included changes in the bone density of the femoral neck, trochanter, and radius and the rate of new vertebra l fractures. Results The mean (+/-SE) bone density of the lumbar spine and trochanter in the etidronate group increased 0.61+/-0.54 and 1.46 +/-0.67 percent, respectively, as compared with decreases of 3.23+/-0. 60 and 2.74+/-0.66 percent, respectively, in the placebo group. The me an differences between the groups after one year were 3.72+/-0.88 perc entage points for the lumbar spine (P = 0.02) and 4.14+/-0.94 percenta ge points for the trochanter (P = 0.02). The changes in the femoral ne ck and the radius were not significantly different between the groups. There was an 85 percent reduction in the proportion of postmenopausal women with new vertebral fractures in the etidronate group as compare d with the placebo group (1 of 31 patients vs. 7 of 32 patients, P = 0 .05), and the etidronate-treated postmenopausal women also had signifi cantly fewer vertebral fractures per patient (P = 0.04). Conclusions I ntermittent etidronate therapy prevents the loss of vertebral and troc hanteric bone in corticosteroid-treated patients. (C) 1997, Massachuse tts Medical Society.