Alendronate in the treatment of Paget's disease of bone

This review reports the results of 2 recently completed long-term, randomised, double-blind, multicentre, controlled studies in which men and women with moderate to severe Paget's disease received oral alendronate 40 mg daily for 6 months One study conducted in the United States, compared the effects of alendronate 60 mg/day (n=41) with those of oral etidronate 400 mg/day (n=47); the other, conducted in the United Kingdom, Australia, and New Zealand, compared the effects of alendronate (n=27) with those of placebo (n=28). In both studies alendronate significantly reduced serum concentrations of alkaline phosphatase by more than 70%, which was significant in comparison with baseline (P < 0.001) and the comparator regimens (P < 0.001). Response to treatment (i.e. a > 60% decrease in or normalisation of serum alkaline phosphatase) was seen in more than three-quarters of patients treated with alendronate in both trials, compared with less than one-third of patients treated with etidronate and no patients treated with placebo. Radiologic scores, reflecting the status of osteolytic lesions, improved in a greater proportion of patients receiving alendronate than in those receiving etidronate or placebo. Histomorphometric analysis performed at 6 months showed that bone formed during alendronate treatment was of normal quality, without evidence of impaired mineralisation or other abnormalities. Alendronate was well tolerated, with an adverse event profile comparable with those of etidronate and placebo. These studies therefore showed that 6 months of treatment with oral alendronate suppresses disease activity in patients with Paget's disease of bone, with beneficial effects on biochemical, radiologic, and histomorphometric indices superior to those of etidronate and placebo.