Effects of two intermittent alendronate regimens in the prevention or treatment of postmenopausal osteoporosis

In clinical practice, a large proportion of patients have bone mass values for which a therapeutic intervention is considered necessary, but the accep ted aim might be the sole preservation or marginal increases of the actual bone mass. These goals might be achieved with lower or intermittent doses o f a powerful agent for the purpose of fewer side effects and improved compl iance. The aim of this study was to assess the effects of two intermittent alendronate regimens in the treatment of postmenopausal osteoporosis. One h undred twenty-four postmenopausal women (age range 52-75 years, at least 7 years since last menopause) with a bone mineral density (BMD) at either the femoral neck or lumbar spine of 2 SD below the mean values of young health y individuals, and without a history of previous osteoporotic fracture, wer e randomly assigned either to calcium/vitamin D supplements, alone or assoc iated with two different intermittent oral alendronate regimens: 20 mg once a week (weekly alendronate group) or 10 mg daily (orally) for 1 month out of 3 (cyclical alendronate group). After 1 year, in both groups given inter mittent alendronate, we observed significant increases in BMD at both the s pine (+2.2 +/- 2.6 and +2.5 +/- 2.9) and femoral neck (+1.6 +/- 4.8 and +1. 5 +/- 2.2) for the weekly and cyclical regimens, respectively. This was ass ociated with a significant diminution of both serum bone-specific alkaline phosphatase and urinary N-telopeptides of collagen type I excretion. In the patients in the control group BMD decreased significantly at the lumbar sp ine, with a slight decline of serum bone-specific alkaline phosphatase, Com pliance with treatment and drug tolerability were good in both alendronate groups. In conclusion, intermittent alendronate administration at cumulativ e doses (and costs) three times lower than those currently recommended for osteoporosis treatment is very well accepted, and is able to significantly increase BMD at the spine and femoral neck and to decrease the markers of b one turnover. These regimens can be clinically useful in the long-term trea tment of postmenopausal osteoporosis without prevalent osteoporotic fractur es, particularly in women with lower compliance for continuous administrati on. (Bone 27:119-122; 2000) (C) 2000 by Elsevier Science Inc. All rights re served.