Risedronate in Postmenopausal Women With Low Bone Density

a Six Month, Multicenter, Randomized, Double-blind, Active-controlled, Parallel Group Study to Estimate the Pharmacodynamic Response of Two Risedronate Regimens Compared With 5mg Daily : 150mg Monthly Dose for Six Months and 15mg Daily for Thirty Days Followed by 150mg Monthly Dose for 5 Months in Postmenopausal Women With Low Bone Density.

The primary objective of this pilot study is to estimate the percent change from baseline at Week 4, Month 6 in NTX bone turnover marker for a monthly 150mg dose of risedronate administered for 6 months and a loading dose regimen of risedronate over a 6 month treatment period both compared to a 5 mg daily dose of risedronate for 6 months The secondary objectives are : To estimate the percent change from baseline at specified visits other than Week 4, Month 6 in NTX for the monthly 150 mg dose of risedronate administered for 6 months and the loading dose regimen of risedronate over a 6 month treatment period both compared to the 5 mg daily dose of risedronate. To estimate the percent change from baseline at all specified visits in serum CTX and bone specific alkaline phosphatase for the monthly 150 mg dose of risedronate administered for 6 months and the loading dose regimen of risedronate over a 6 month treatment period both compared to the 5 mg daily of risedronate. To estimate the percent change from baseline at Month 6 in lumbar spine BMD for the monthly 150 mg dose of risedronate administered for 6 months and the loading dose regimen of risedronate over a 6 month treatment period both compared to the 5 mg daily dose of risedronate. To evaluate the safety of the risedronate 150 mg monthly and the loading dose regimen.

Inclusion Criteria: ambulatory women,postmenopausal >= 5 years have lumbar spine baseline BMD within the following criterion : Hologic: <= 0.827 g/cm2 or Lunar: <= 0.942 g/cm2 or Norland: <= 0.768 g/cm2 be in general good health as determined by medical history, physical examination and laboratory tests Exclusion Criteria: serum 25-OH vitamin D level <= 12 ng/ml history of osteomalacia history of active hyperparathyroidism or hyperthyroidism hypocalcemia or hypercalcemia from any cause depot injection >10,000 IU Vitamin D in the past 9 months prior to starting the investigational product use of Vitamin D supplementation within 3 months prior to starting the investigational product use of any of the following medications within a specified number of months prior to starting the investigational product : any bisphosphonate. use of any fluoride with the exception of fluoride use for oral hygiene strontium other bone active agents subcutaneous estrogen implant oral or parenteral glucocorticoids anabolic steroids estrogen or estrogen-related drugs, except for low dose vaginal creams progestogen calcitonin, calcitriol, or calcifediol any allergic or abnormal reaction to bisphosphonates creatinine clearance < 30 ml/min