Fracture Risk Following Discontinuation of Teriparatide: A Review of the Literature.

OBJECTIVE: To review and summarize studies on the changes in bone mineral density (BMD) and fracture risk following discontinuation of teriparatide therapy.

DATA SOURCES: A search of PubMed (1966-May 2016) and International Pharmaceutical Abstracts (1970-May 2016) was conducted using the Medical Subject Headings terms teriparatide, osteoporosis, and withholding treatment. Free text searches included drug holiday, discontinuation, and drug discontinuation.

STUDY SELECTION AND DATA EXTRACTION: These searches yielded 79 articles. There were 7 articles reviewed that addressed the effects of teriparatide discontinuation on markers of overall bone health and fracture risk.

DATA SYNTHESIS: Teriparatide is a recombinant human parathyroid hormone that is indicated for a lifetime maximum of 24 months in the United States for the treatment of osteoporosis in men and women at high fracture risk. There is inconsistent evidence regarding retained skeletal integrity resulting from increased bone resorption. Study analyses have shown that female patients seem to have more reduction in BMD upon teriparatide discontinuation. Several studies evaluating teriparatide discontinuation were follow-up studies with small patient populations, limiting the generalizability and statistical rigor associated with assessing these outcomes. In addition, the majority of patients were receiving bisphosphonate therapy, and the true effect of discontinuing teriparatide remains unknown.

CONCLUSION: Independent patient risk factors should be taken into consideration when weighing the risk-vs.-benefit of initiating and discontinuing teriparatide therapy. Additional randomized control trials should be conducted to determine long-term effects of discontinuing teriparatide in the presence and absence of other bone-strengthening agents.