Individual Antidepressants and the Risk of Fractures in Older Adults: A New User Active Comparator Study

OBJECTIVE: To determine the risk of hip–pelvis and other non-vertebral fractures in older adults using antidepressants (ADs). METHODS: We conducted a case–control study nested in a cohort of new users of ADs aged ≥65 years without prior hip–pelvis or other non-vertebral fractures, identified in the German Pharmacoepidemiological Research Database (GePaRD) during 2005–2014. Cases were patients first hospitalized for hip–pelvis or other non-vertebral fractures. Up to 100 controls per case were selected using incidence density sampling. AD use was ascertained at index date (ID) based on the supply of last dispensing. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression with current users of mirtazapine as reference (active comparator). RESULTS: A total of 39,853 cases of hip–pelvis fracture (80% women, median age 81 years) and 31,577 cases of other fractures (84% women, median age 79 years) were matched to >3 million controls. For hip–pelvis fracture, aORs in current users were about 1.3 with little variation between individual ADs, ranging from 1.33 for citalopram (95% CI 1.27–1.39) to 1.28 for amitriptyline (1.21–1.35). For other fractures, the aORs were highest in current users of citalopram (1.50; 1.42–1.58) and duloxetine (1.54; 1.39–1.71) and lowest for amitriptyline (1.18; 1.11–1.26) and trimipramine (1.16; 1.03–1.29). For all examined ADs, the aORs were higher for other fractures than for hip–pelvis fracture. CONCLUSION: The risk of fractures varies between ADs, but for most agents is higher than the risk for mirtazapine. When treating older adults with ADs, prescribers should carefully consider the risk profile of individual ADs regarding fractures, which are a major health problem in this population.