Parathyroid Hormone (PTH) With Alendronate for Osteoporosis

This study investigates the effectiveness of parathyroid hormone (PTH) in combination with alendronate, a standard treatment for osteoporosis that blocks or reduces bone loss. We are using alendronate because it may help protect patients against any possible harmful effects of PTH in cortical bone such as the long bones or hip. We are testing two different treatment schedules of PTH-one in which we give PTH daily and one in which we give PTH for 3 out of every 6 months in a cyclical fashion. The entire study is 21 months long; the active treatment period is 18 months with a 6-month followup period. The main effects we will look for in this study are changes in body chemicals that are signs of bone formation or bone breakdown, and changes in bone density throughout the skeleton. We will randomly assign all study participants, who are women aged 50 and over, to either stay on alendronate alone, receive daily continuous PTH plus alendronate, or receive daily PTH for 3 months out of every 6 for a total of three separate 3-month cycles of PTH plus daily alendronate.