Risk of Fracture Associated with Pregabalin or Mirogabalin Use: A Case-Case-Time-Control Study Based on Japanese Health Insurance Claims Data.

Background: Pregabalin is widely used for neuropathic pain. Mirogabalin, a newer gabapentinoid, was recently introduced in several Asian countries. A previous case-crossover study showed an association between pregabalin and fall-related injuries, but the findings may have been affected by biases from individual- and population-level exposure time trends, and generalizability was limited due to a focus on a middle-aged population. Further, no findings have appeared on mirogabalin and its association with fall-related fractures.

Objective: We conducted a case-case-time-control study to investigate the risk of fracture associated with pregabalin and mirogabalin in a population with broad demographic coverage.

Methods: Incident fractures were identified from a Japanese claims database. For each case, hazard (days 1-30 before the fracture event) and control windows (days 61-90 before the event) were set. Each current case was matched by age and sex to a future case, defined as a patient who experienced a fracture 120-365 days later. Odds ratios (ORs) were estimated using conditional logistic regression models.

Results: A total of 814,216 and 460,811 cases were included in the pregabalin and mirogabalin analyses, respectively. ORs were 1.35 (95% confidence interval 1.28-1.43) for pregabalin and 1.53 (1.35-1.72) for mirogabalin, indicating an increased risk of fracture with both drugs. These results remained consistent and robust across sensitivity and subgroup analyses, except in patients under 65 years of age.

Conclusion: Given this observed risk and the fact that these medications are commonly prescribed to older populations, caution is warranted in clinical use.