Original Article
Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Anesthesiol. Jul 27, 2014; 3(2): 181-188
Published online Jul 27, 2014. doi: 10.5313/wja.v3.i2.181
Paroxetine vs pregabalin for the management of neuropathic pain in multiple sclerosis
Dana A Turcotte, Malcolm Doupe, Mahmoud Torabi, Andrew J Gomori, Karen Ethans, Farid Esfahani, Katie Galloway, Michael P Namaka
Dana A Turcotte, Michael P Namaka, Faculty of Pharmacy, University of Manitoba, Winnipeg, Manitoba R3E 0T5, Canada
Malcolm Doupe, Manitoba Centre for Health Policy, Winnipeg, Manitoba R3E 3P5, Canada
Mahmoud Torabi, Department of Community Health Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba R3E 3P5, Canada
Andrew J Gomori, Section of Neurology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
Karen Ethans, Michael P Namaka, Section of Physical Medicine and Rehabilitation, University of Manitoba, Winnipeg, Manitoba R3A 1R9, Canada
Farid Esfahani, Winnipeg Clinic, Winnipeg, Manitoba R3C 0N2, Canada
Katie Galloway, Department of Statistics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
Michael P Namaka, Department of Human Anatomy, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
Author contributions: Turcotte DA, Doupe M and Torabi M, Namaka MP were involved in study design and initial planning; Turcotte DA, Gomori AJ, Ethans K, Esfahani F and Namaka MP were involved in acquisition of patient data; Turcotte DA, Doupe M, Torabi M and Galloway K were responsible for data analysis and interpretation; Turcotte DA wrote the original manuscript draft; Turcotte DA, Doupe M, Torabi M, Gomori AJ, Ethans K, Esfahani F, Galloway K and Namaka MP critically reviewed and revised content; all listed authors approved final version of this manuscript for publication.
Correspondence to: Dr. Dana A Turcotte, Faculty of Pharmacy, University of Manitoba, 750 McDermot Avenue, Winnipeg, Manitoba R3E 0T5, Canada. danaturcotte19@gmail.com
Telephone: +1-204-2955358 Fax: +1-204-4747617
Received: August 15, 2013
Revised: June 12, 2014
Accepted: June 14, 2014
Published online: July 27, 2014
Processing time: 370 Days and 9.3 Hours
Abstract

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 (VASpain) and daily impact of pain on daily activities (VASimpact). 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 (VASpain, VASimpact). 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.

Keywords: Multiple sclerosis; Neuropathic pain; Paroxetine; Pregabalin; Clinical trial

Core tip: The high attrition rates identified in the paroxetine study arm suggest that it be used with caution for multiple sclerosis (MS)-induced neuropathic pain (NPP). Although analysis of the primary endpoint measures revealed no significant differences, there was a trend toward marked improvement for visual analogue scale and daily impact of pain on daily activities in favor of pregabalin. However, due to the premature study cessation, definitive confirmation of pregabalin’s enhanced efficacy was not possible. These results reinforce the recognized challenges clinicians encounter in drug selection for MS-induced NPP. Due to the lack of well-designed controlled NPP trials in this population, effective and well-tolerated treatment selection poses a significant clinical challenge.