| 'Fosamax' is a bisphosphonate that inhibits osteoclastic bone resorption with no direct effect on bone formation. The bone formed during treatment with 'Fosamax' is of normal quality. Treatment of post-menopausal osteoporosis The effects of 'Fosamax' on bone mass and fracture incidence in post-menopausal women were examined in two initial efficacy studies of identical design (n=994) as well as in the Fracture Intervention Trial (FIT: n=6,459).In the initial efficacy studies, the mean bone mineral density (BMD) increases with 'Fosamax' 10 mg/day relative to placebo at three years were 8.8%, 5.9% and 7.8% at the spine, femoral neck and trochanter, respectively. Total body BMD also increased significantly. There was a 48% reduction in the proportion of patients treated with 'Fosamax' experiencing one or more vertebral fractures relative to those treated with placebo. In the two-year extension of these studies BMD at the spine and trochanter continued to increase and BMD at the femoral neck and total body were maintained.FIT consisted of two placebo-controlled studies: a three-year study of 2,027 patients who had at least one baseline vertebral (compression) fracture and a four-year study of 4,432 patients with low bone mass but without a baseline vertebral fracture, 37% of whom had osteoporosis as defined by a baseline femoral neck BMD at least 2.5 standard deviations below the mean for young, adult women. In all FIT patients with osteoporosis from both studies, 'Fosamax' reduced the incidence of: 1 vertebral fracture by 48%, multiple vertebral fractures by 87%, 1 painful vertebral fracture by 45%, any painful fracture by 31% and hip fracture by 54%.Overall these results demonstrate the consistent effect of 'Fosamax' to reduce the incidence of fractures, including those of the spine and hip, which are the sites of osteoporotic fracture associated with the greatest morbidity.Prevention of post-menopausal osteoporosis The effects of 'Fosamax' to prevent bone loss were examined in two studies of post-menopausal women aged 60 years. In the larger study of 1,609 women ( 6 months post-menopausal) those receiving 'Fosamax' 5 mg daily for two years had BMD increases of 3.5%, 1.3%, 3.0% and 0.7% at the spine, femoral neck, trochanter and total body, respectively. In the smaller study (n=447), similar results were observed in women (6 to 36 months post-menopausal) treated with 'Fosamax' 5 mg daily for three years. In contrast, in both studies, women receiving placebo lost bone mass at a rate of approximately 1% per year. The longer term effects of 'Fosamax' in an osteoporosis prevention population are not known but clinical trial extensions of up to 10 years of continuous treatment are currently in progress.Concomitant use with oestrogen/hormone replacement therapy (HRT) The effects on BMD of treatment with 'Fosamax' 10 mg once-daily and conjugated oestrogen (0.625 mg/day) either alone or in combination were assessed in a two-year study of hysterectomised, post-menopausal, osteoporotic women. At two years, the increases in lumbar spine BMD from baseline were significantly greater with the combination (8.3%) than with either oestrogen or 'Fosamax' alone (both 6.0%).The effects on BMD when 'Fosamax' was added to stable doses (for at least one year) of HRT (oestrogen ± progestin) were assessed in a one-year study in post-menopausal, osteoporotic women. The addition of 'Fosamax' 10 mg once-daily to HRT produced, at one year, significantly greater increases in lumbar spine BMD (3.7%) vs. HRT alone (1.1%).In these studies, significant increases or favourable trends in BMD for combined therapy compared with HRT alone were seen at the total hip, femoral neck and trochanter. No significant effect was seen for total body BMD.Treatment of osteoporosis in men The efficacy of 'Fosamax' 10 mg once daily in men (ages 31 to 87; mean, 63) with osteoporosis was demonstrated in a two-year study. At two years, the mean increases relative to placebo in BMD in men receiving 'Fosamax' 10 mg/day were: lumbar spine, 5.3%; femoral neck, 2.6%; trochanter, 3.1%; and total body, 1.6%. 'Fosamax' was effective regardless of age, race, gonadal function, baseline rate of bone turnover, or baseline BMD. Consistent with much larger studies in post-menopausal women, in these 127 men, 'Fosamax' 10 mg/day reduced the incidence of new vertebral fracture (assessed by quantitative radiography) relative to placebo (0.8% vs. 7.1%) and, correspondingly, also reduced height loss (-0.6 vs. -2.4 mm).Glucocorticoid-induced osteoporosis The efficacy of 'Fosamax' 5 and 10 mg once-daily in men and women receiving at least 7.5 mg/day of prednisone (or equivalent) was demonstrated in two studies. At two years of treatment, spine BMD increased by 3.7% and 5.0% (relative to placebo) with 'Fosamax' 5 and 10 mg/day respectively. Significant increases in BMD were also observed at the femoral neck, trochanter, and total body. In post-menopausal women not receiving oestrogen, greater increases in lumbar spine and trochanter BMD were seen in those receiving 10 mg 'Fosamax' than those receiving 5 mg. 'Fosamax' was effective regardless of dose or duration of glucocorticoid use. Data pooled from three dosage groups (5 or 10 mg for two years or 2.5 mg for one year followed by 10 mg for one year) showed a significant reduction in the incidence of patients with a new vertebral fracture at two years ('Fosamax' 0.7% vs. placebo 6.8%).Paediatric patients:
Alendronate sodium has been studied in a small number of patients with osteogenesis imperfecta under the age of 18 years. Results are insufficient to support the use of alendronate sodium in paediatric patients with osteogenesis imperfecta.
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