Effect of zoledronic acid compared with raloxifene on bone turnover markers in postmenopausal women with low bone...

The aim of this study was to assess the effects of zoledronic acid and raloxifene on bone turnover markers.

This multicenter, randomized, double-blind study involved 110 postmenopausal women with low bone mineral density who received either a single intravenous infusion of zoledronic acid 5 mg or 6 months of daily oral raloxifene 60 mg. The primary efficacy variable was change from baseline in the bone resorption marker urine N-telopeptide of type I collagen. The secondary efficacy variable was change from baseline in the bone formation marker serum bone-specific alkaline phosphatase. Analysis time points were at 2, 4, and 6 (primary) months.

At 6 months, zoledronic acid produced a significantly greater reduction than did raloxifene in urine N-telopeptide of type I collagen (P < 0.001). Zoledronic acid also yielded significantly greater decreases in urine N-telopeptide of type I collagen at 2 and 4 months and in serum bone-specific alkaline phosphatase at all time points (P < 0.001 vs raloxifene for all comparisons). Both treatments were well tolerated. More adverse events occurred in the zoledronic acid group; these were primarily transient postdose symptoms that occurred within the first 3 days after the infusion.

Zoledronic acid demonstrated significantly greater decreases in bone turnover markers than did raloxifene in postmenopausal women with low bone mass.