The effects of alendronate on bone turnover and bone quality

During Phase III clinical trials with alendronate, biochemical and histolog ical studies assessed bone turnover and bone qualify in patients treated fo r 3 years. Patients were randomised in double-blind fashion to receive plac ebo, alendronate 5 or 10 mg/day for 3 years or 20 mg/day for 2 years follow ed by 5 mg/day for I year. All patients also received 500 mg/day of calcium carbonate. Decreases in bone resorption with alendronate preceded decrease s in bone formation. After approximately 6 months of continuous treatment, a new steady state of bone turnover was attained leading to-the increase in bone density. No subsequent decrease in the rate of bone turnover or of fr ozen bone was noted Alendronate treatment did not impair bone mineralisatio n, induce the formation of woven bone or have any other adverse effects on bone quality.