Adverse events, including fractures, among older patients receiving mirogabalin versus pregabalin: A retrospective cohort study using a large claims database in Japan.

Background: Mirogabalin has a mechanism similar to that of pregabalin in the treatment of neuropathic pain. However, it remains unclear whether these drugs differ in terms of serious side effects, such as fall-related fractures, in older patients. This study aimed to investigate whether mirogabalin is associated with a decrease in adverse events, including fall-related fractures, compared with pregabalin.

Methods: We performed a retrospective cohort study using the DeSC database, a large administrative claims database in Japan. This study included 130,244 patients ≥65 years taking mirogabalin or pregabalin between April 2019 and May 2021. The primary outcome was defined as the occurrence of fractures or switching to other medications and was compared between those receiving mirogabalin and pregabalin using Kaplan-Meier curves and multivariable Cox proportional hazards models. A sensitivity analysis was performed regarding patients who received mirogabalin or pregabalin without other analgesic medications at the initial dose.

Results: During a median follow-up of 2.8 months, 29,686 (22.8%) and 100,558 (77.2%) received mirogabalin and pregabalin, respectively. The rates of the outcome in the mirogabalin and pregabalin groups were 50.1 and 42.8 per 100 person-years. Cox regression analysis showed that mirogabalin was associated with a lower risk of the outcome (hazard ratio, 0.93; 95% confidence interval, 0.87-1.00). However, sensitivity analysis did not demonstrate a difference in the outcome between the mirogabalin and pregabalin groups without other analgesic medications (hazard ratio, 0.93; 95% confidence interval, 0.86-1.01).

Conclusions: Our analyses suggest that the outcome may be less likely in the mirogabalin group; however, the difference appears to be clinically insignificant. Further studies are warranted to confirm these findings.