• - Whether the increase from baseline to 18 months in lumbar spine BMD induced by teriparatide statistically signficantly exceeds that obtained with alendronate in women and men taking GC for a minimum of 3 months
• To determine:

• Change From Baseline at 18 Month Endpoint in Lumbar Spine Bone Mineral Density (BMD), Female Subset [ Time Frame: 18 month endpoint ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Lumbar Spine Bone Mineral Density (BMD), Women and Men Combined [ Time Frame: 3, 6, 12, 18, 24, 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Lumbar Spine Bone Mineral Density (BMD), Female Subset [ Time Frame: 3, 6, 12, and 18 months ] [ Designated as safety issue: No ]
• Change From Baseline in Lumbar Spine Bone Mineral Density (BMD), Women and Men Combined [ Time Frame: 24 and 36 months and Endpoint at 36 months ] [ Designated as safety issue: No ]
• Change From Baseline in Femoral Neck Bone Mineral Density (BMD), Women and Men Combined [ Time Frame: 18, 24, 36 months, and 18 and 36 month endpoints ] [ Designated as safety issue: No ]
• Change From Baseline in Total Hip Bone Mineral Density (BMD), Women and Men Combined [ Time Frame: 18, 24, 36 months, and 18 and 36 month endpoints ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Femoral Neck Bone Mineral Density (BMD), Women and Men Combined [ Time Frame: 12, 18, 24, and 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Total Hip Bone Mineral Density (BMD), Women and Men Combined [ Time Frame: 12, 18, 24, and 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Bone Turnover Markers in Subset of Patients - Serum N-Terminal Propeptide of Type 1 Procollagen [ Time Frame: 1, 6, 18, and 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Bone Turnover Markers in Subset of Patients - Serum C-Terminal Propeptide of Type 1 Procollagen [ Time Frame: 1, 6, 18, and 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Bone Turnover Markers in Subset of Patients - Bone-Specific Alkaline Phosphatase [ Time Frame: 1, 6, 18, and 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Bone Turnover Markers in Subset of Patients - Serum Type 1 Collagen Degradation Fragments [ Time Frame: 1, 6, 18, and 36 months ] [ Designated as safety issue: No ]
• Time Course of Change From Baseline in Bone Turnover Markers in Subset of Patients - Osteocalcin [ Time Frame: 1, 6, 18, and 36 months ] [ Designated as safety issue: No ]
• Any Fracture, Nonvertebral Fractures, Vertebral Fractures, Clinical Vertebral Fractures, and Severity Fractures [ Time Frame: 36 months ] [ Designated as safety issue: No ]

• - Whether the increase from baseline to 18 months in lumbar spine BMD induced by teriparatide statistically significantly exceeds that obtained with alendronate in women taking GC for a minimum of 3 months
• - The time course of BMD response at the lumbar spine from baseline until 18 months in women and men combined, and in women separately
• To assess the effects of the therapies on:
• - The change from baseline in femoral neck and total hip BMD at 18 months, 24 months, and 36 months, and in lumbar spine BMD at 24 months and 36 months
• - The time course of BMD response at the femoral neck and total hip from baseline until 18 months
• - The time course of BMD response at the lumbar spine, femoral neck, and total hip from baseline until 36 months
• - The time course of response of biochemical markers of bone turnover from baseline until 18 months in subjects from a subset of the study centers
• - The time course of response of biochemical markers of bone turnover from baseline until 36 months in subjects from a subset of the study centers
• - Any fracture, nonvertebral fractures, vertebral fractures, clinical vertebral fractures, and severity fractures at 36 months
• - Adverse experience, laboratory variables, and other aspects of subject safety and tolerance of the study drugs

Osteoporosis is a condition in which the amount of bone is reduced, the bones are weak, and there is an increased risk for fractures. Glucocorticoids (such as prednisone) are prescribed to treat a large number of conditions such as arthritis and asthma. When taken for several months or longer, glucocorticoids can cause bone loss and lead to a form of osteoporosis called "glucocorticoid-induced osteoporosis." This study compared the effects of teriparatide, the study drug, with alendronate, an approved drug for treating glucocorticoid-induced osteoporosis.

• Drug: Teriparatide
• Drug: Alendronate Sodium
• Drug: Placebo

• Experimental: Teriparatide 20 micrograms/day injection plus oral placebo, 36 months
• Active Comparator: Alendronate 10 mg/day oral plus injection placebo, 36 months

Inclusion Criteria:

• Men or women age 21 years or older
• Taking on average 5.0 mg/day prednisone or equivalent for at least 3 months prior to screening

Exclusion Criteria:

• Taking bisphosphonates within past 6 months
• More than 30 micrograms/day of estradiol or equivalent in past 3 months
• History of alcoholism or drug abuse in past year
• Pregnant women or nursing mothers