Is it safe to continue teriparatide beyond 3 years in a patient with severe osteoporosis and atypical fracture of the femur?  

The original label for teriparatide limited its lifetime use to 2 years. Two years is as long as the Phase 3 trial in postmenopausal women had gone when a decision to terminate the trial voluntarily was made by Eli Lilly, due to the finding of osteosarcoma in rats. Thus, the safety data was limited ...