Non-Motor Symptoms in Gabapentin Users: A Clinical Evaluation

Objective: Gabapentin is widely used for neuropathic pain, epilepsy, and other indications; however, its non-motor side effects remain understudied. This prospective, cross-sectional observational study aimed to evaluate non-motor symptoms in gabapentin users, assessed with the Non-Motor Symptom Scale (NMSS). Methods: The Turkish version of the NMSS was administered once to 105 patients who had been receiving gabapentin for at least 120 days and to 107 demographically matched healthy controls at our Non-Motor Symptom Scale (NMSS) between January and December 2022. Exclusion criteria included neurodegenerative diseases, diabetes, psychiatric disorders, and thyroid dysfunction. Group comparisons were performed using independent samples t-tests for continuous variables and chi-square or Fisher’s exact tests for categorical data. Results: Gabapentin users had significantly higher total NMSS scores than controls (11.6 ± 5.56 vs. 6.03 ± 4.28, P < 0.001). Symptoms such as salivation, constipation, urgency, nocturia, pain, memory impairment, depression, anxiety, sexual dysfunction, orthostatic hypotension, daytime sleepiness, and leg edema were reported more frequently in the gabapentin group (P < 0.05). Conclusion: Gabapentin use was associated with a higher frequency of non-motor symptoms, as assessed by the NMSS. This study suggests that the NMSS may serve as a structured tool for the systematic screening of non-motor symptoms in patients receiving gabapentin. Prospective studies with indication-matched controls and validated assessment tools are warranted to confirm these associations.