OPTAMISE: Clinical Effectiveness of Teriparatide After Alendronate or Risedronate Therapy in Osteoporotic Postmenopausal Women

To determine how prior therapy with alendronate or risedronate in postmenopausal women with osteoporosis influences the clinical effectiveness of teriparatide; The primary objective of the study is to compare the teriparatide (human, recombinant PTH\[1-34\])-associated change from baseline in a marker of bone formation, N-terminal propeptide of type I collagen (P1NP), between subjects previously treated with risedronate and those previously treated with alendronate.