Paroxetine vs pregabalin for the management of neuropathic pain in multiple sclerosis

AIM: To compare the effectiveness and tolerability of paroxetine vs pregabalin for the management of multiple sclerosis(MS)-induced neuropathic pain(NPP).METHODS: A randomized, flexible-dose open-label 8-wk study involving 21 relapsing-remitting MS patients with MS-induced NPP was conducted to evaluate the effectiveness and tolerability of pregabalin versus paroxetine for pain management. The trial included a 3-wk dose titration phase followed by a 5-wk stable dose phase. Primary outcome measures included daily patient-reported pain intensity as measured using a 100 mm visual analogue scale(VAS pain) and daily impact of pain on daily activities(VAS impact). Hierarchical regression modeling was conducted on each outcome to determine if within person VAS trajectory for pain and impact differed across study groups, during 56 d follow-up. RESULTS: Attrition rates were significantly greater(P < 0.001) in the paroxetine versus pregabalin study group(70% vs 18.2%, respectively). Average study duration between study groups also significantly differed(P < 0.001). Paroxetine participants completed an average of 27.3 d of treatment vs 49.5 d in the pregabalin group, with the majority of patients withdrawing due to adverse events. Due to the high attrition rates in the paroxetine study arm, the investigators stopped the study prior to achieving complete recruitment. As such, no significant differences between pregabalin and paroxetine study arms were noted for the primary outcome measures(VAS pain, VAS impact). Comparative assessment of baseline patient characteristics also revealed no significant differences between the study arms. CONCLUSION: High attrition rates associated with paroxetine use suggest that it be used with caution for MS-induced NPP. Efficacy outcomes could not be assessed due to attrition.