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

Table 1 Study eligibility requirements

Inclusion criteria	Exclusion criteria
Males and females 18-65 years old	Breastfeeding
Clinically definite RRMS	History of alcohol or other substance abuse
EDSS ≤ 6.5	Significant hepatic/renal insufficiency
VAS score for NPP symptoms > 5	Significant cardiac disease (CHF, arrhythmia); hypertension
Pain present for at least 3 mo	Hypersensitivity/allergy to study medications or their derivatives
Negative serum pregnancy test	No current therapeutic duplications No history of psychotic/non-psychotic emotional disorders

Inclusion and exclusion criteria for enrolment in the study are noted above. RRMS: Relapsing-remitting multiple sclerosis; EDSS: Expanded Disability Status Scale; NPP: Neuropathic pain; VAS: Visual analogue scale; CHF: Congestive heart failure.

Table 2 Paroxetine/pregabalin flexible-dose titration schedule

Schedule	Dosage
	Paroxetine	Pregabalin
Day 1	20 mg once daily	75 mg twice daily
Day 8	40 mg once daily	150 mg twice daily
Day 15	50 mg once daily	300 mg twice daily

Flexible-dose titration schedule for each group is presented. Assuming therapy was well-tolerated patients were instructed to increase dosages as indicated above. If, however, at any point patients experienced intolerable side effects they were instructed to contact study investigators for tailored dosing instructions.

Table 3 Study patient characteristics

	Total	Paroxetine	Pregabalin	P value
n	22	10	11	N/A
Demographic
Age: mean (SD)	45.7(12.49)	43.1(12.85)	48.1(12.28)	0.374
Sex: % female	81	90	72.7	NS
Clinical
EDSS: mean (SD)	2.3(1.44)	2.6(1.29)	1.9(1.57)	0.34
Baseline pain: mean (SD)	71.5(10.66)	68.3(10.11)	74.7(10.73)	0.19
Duration of pain (mo): mean (SD)	25.75(19.77)	22.5(19.72)	29(20.31)	0.48
Time since MS diagnosis (yr): mean (SD)	9.39(8.63)	7.8(8.79)	11.38(8.57)	0.4
Analysis
% withdrawal from study	40.9	70	18.2	< 0.001
Average final daily dose (mg) attained (% of maximum possible)	N/A	31 (62)	422.7 (70.5)	N/A

Baseline characteristics–categorized as either “demographic” or “clinical” are presented collectively for all patients combined (n = 22) as well as individually for paroxetine (n = 10) and pregabalin (n = 11) patient groupings. Where appropriate, mean and SD are provided. “Analysis” subheading provides information on the number of patients who withdrew prematurely from the study (“% withdrawal from study”) by group as well as the final average daily dose attained in each group. P values have been provided to estimate equivalence of groups. EDSS: Expanded disability status scale; NS: No significant; N/A: Not available.

Table 4 Average study duration (d) by study group

	Average study duration by group (d)
	n	Mean days in study	SD	Range of values
				Lower	Upper
Paroxetine	10	27.3	21.6	5	58
Pregabalin	11	49.5	15.7	14	63

The mean duration of participation in the study by group is presented, with associated SD and range; Independent t test between groups, P < 0.01.

Table 5 Univariate comparison results: VAS_pain and VAS_impact

	VASpain	VASimpact
	RR	RR
Group	8.7270	3.4270
Day	0.5036	0.5065
Group × day	0.1513	0.1918

Univariate comparison results are presented on data from study participants completing the study. No significant findings were noted between comparisons. RR: Relative risk.