Neurological adverse events associated with baclofen: A pharmacovigilance study based on FDA adverse event reporting system

Yunhan ZhaoHaoxiang HuJiesheng MaoJianghai HeYihan ZhangXiaokai Yang^*

• Wenzhou People’s Hospital, Wenzhou, China

Background: Baclofen, a centrally acting muscle relaxant, is widely utilized for the management of muscle spasms and alcohol use disorders associated with conditions. However, its neurological safety and tolerability in a large population remain limited. This study aimed to assess the neuro-logical safety and potential risks of baclofen in the real world.Methods: Data covering the period from the first quarter of 2004 to the third quarter of 2024 were collected from the Food and Drug Administration Adverse Event Reporting System (FAERS). Four disproportionality analysis methods were employed: the Reporting Odds Ratio (ROR), the Propor-tional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and the Multi-item Gamma Poisson Shrinkage (MGPS). These methods were used to detect and evaluate adverse events (ADEs) associated with baclofen. Additionally, the time to onset (TTO) analysis was conducted.Results: A total of 432 neurological-related preferred terms (PTs) were identified. The number of PT that were positive for all four algorithms was 40, and the top 5 PT were Hypotonia, Encephalo-pathy, Coma, Unresponsive to stimuli, and Cerebrospinal fluid leakage. The top 5 PTs for ROR val-ues are Intracranial hypotension [ROR 66.24 (55.45 - 79.13)], Cerebrospinal fluid leakage [ROR 51.34 (45.84 - 57.51)], Autonomic dysreflexia [ROR 47.4 (32.27 - 69.63)],Basal ganglion degenera-tion [ROR 33.03 (18.54 - 58.84)], Sciatic nerve palsy [ROR 21.6 (11.14 - 41.87)]. The median onset time for baclofen -related ADEs was 27 days. Most cases (n=241, 55.5%) occurred within the first month of baclofen administration. In an analysis of severe vs non-severe ADEs, the study found that the incidence of severe cases was higher than that of non-severe cases, with no gender-related dif-ferences observed.Conclusions: This study identified clinically significant PTs using four different algorithms and performed gender subgroup analysis. The TTO analysis indicated that the onset of most ADEs oc-curred within 27 days. Furthermore, the frequency of severe ADEs was higher than that of non-severe ones. Clinicians should closely monitor for neurological adverse effects caused by baclofen, particularly severe ADEs, and consider individualized dosing strategies. Further research based on real-world data is needed to validate these findings.