RESUMEN
BACKGROUND: Bisphosphonates are now well established as successful antiresorptive agents for the prevention and treatment of osteoporosis. We investigated the effect of cyclic intravenous treatment with an aminobisphosphonate, pamidronate in cases of primary osteoporosis. METHODS: Eighteen patients with primary osteoporosis (bone mineral density BMD t-score < -2.5) received four courses of pamidronate (30 mg with 500 mL normal saline over 2 hours every 3 months). The serum biochemical parameters and bone turnover markers were measured before each treatment. The bone pain score, medication score, and the side effects were also monitored. BMD and simple spine X-ray were performed before and 1 year after of treatment. RESULTS: BMD at the lumbar spine (L2-4) significantly increased from 0.798+/-0.110 g/cm2 to 0.860+/-0.107 g/cm2 after 1 year of treatment with pamidronate: by +8.3+/-9.4% of baseline. BMDs at the femoral neck, Ward s triangle and the trochanter also increased, but not significantly. Serum total alkaline phosphatase (p<0.05) and urine deoxypyridinoline/creatinine (p=0.069) decreased with treatment. Other bone turnover markers were unchanged. The bone pain score decreased significantly. None of the patients experienced a new fracture during treatment. The frequency of the side effects following the first infusion was 61.1% (a transient fever and myalgia with flu-like symptoms in 10 patients and mild phlebitis in 1 patient). However, only two patients complained of flu-like symptoms after second infusion, and no patient complained following the third infusion. CONCLUSION: Cyclic intravenous treatment of pamidronate every three months was effective in increasing BMD and in the decreasing bone turnover rate, and was relatively well tolerated in primary osteoporotic women.