Evidence Table 3Efficacy of Anticonvulsants1,2

StudyTreatment# of patients improved/N (%)Odds ratioMean ValuesEffect size or p-value
NBefore TreatmentAfter Treatment
COMPARISONS WITH PLACEBO (AND DOSING STUDIES)
Divalproex sodium
Klapper, 1996Divalproex sodium, 1500 mg/day for 3 mos20/44 (45%)3.1 (1.2 to 7.9)
≥ 50% reduction in HF
44-1.7 (reduction from baseline)p≤0.05 (divalproex sodium better)
HF
Placebo9/42 (21%)42-0.5 (reduction from baseline)
Klapper, 1996Divalproex sodium, 1000 mg/day for 3 mos17/40 (43%)2.7 (1.03 to 7.1)
≥ 50% reduction in HF
40-2.0 (reduction from baseline)p≤0.05 (divalproex sodium better)
HF
Placebo9/42 (21%)42-0.5 (reduction from baseline)
Klapper, 1996Divalproex sodium, 500 mg/day for 3 mos20/45 (44%)2.9 (1.1 to 7.5)
≥ 50% reduction in HF
45-1.7 (reduction from baseline)p≤0.05 (divalproex sodium better)
HF
Placebo9/42 (21%)42-0.5 (reduction from baseline)
Mathew, Saper, Silberstein, et al., 1995Divalproex sodium, 1087 mg/day (average) for 3 mos33/69 (48%)5.7 (1.98 to 16)
≥ 50% reduction in HF
696.03.5p≤0.001 (divalproex sodium better)
HF
Placebo5/36 (14%)366.45.7
Sodium valproate
Hering and Kuritzky, 1992Sodium valproate, 800 mg/day for 2 mos--29*-8.8260.93 (0.39 to 1.5)
HF
Placebo-29*-15.586
Jensen, Brinck, and Olesen, 1994Sodium valproate (slow-release), 1000–1500 mg/day for 3 mos22/34 (65%)7.1 (2.4 to 21)
≥ 50% reduction in HF
34*6.13.5p=0.0018 (sodium valproate better)
HF
Placebo7/34 (21%)34*6.16.1
Carbamazepine
Rompel and Bauermeister, 1970Carbamazepine, 600 mg/day for 6 wks26/45 (58%)12 (3.9 to 35)
Marked or complete improvement in HI
45*-0.67-
HF
Placebo5/48 (10%)48*-3.87
Clonazepam
Stensrud and Sjaastad, 1979Clonazepam, 1 mg/day for 1 mo--38*--p=0.20 (n.s.)
HI
Placebo-38*--
Gabapentin
Wessely, Baumgartner, Klingler, et al., 1987Gabapentin, 900 mg/day for 3 mos--146.54.1-
HF
Placebo-194.34.0
COMPARISONS WITH BETA-BLOCKERS
Divalproex sodium vs. propranolol
Klapper, 1994Divalproex sodium, 1100 mg/day (average) for 2 mos--12*-10.9-
HF
Propranolol, 140 mg/day (average) for 2 mas-12*-20.4
Carbamazepine vs. prindolol
Anthony, Lance, and Somerville, 1972Carbamazepine, 600 mg/day for 1 mo10/30 (33%)0.29 (0.10 to 0.81)
≥ 50% reduction in HF
----
Prindolol, 10 mg/day for 1 mo21/33 (64%)---
COMPARISONS WITH ALPHA-2 AGONISTS
Carbamazepine vs. clonidine
Anthony, Lance, and Somerville, 1972Carbamazepine, 600 mg/day for 1 mo10/30 (33%)0.44 (0.15 to 1.2)
≥ 50% reduction in HF
----
Clonidine, 225 μg/day for 1 mo16/30 (53%)---
1

Key to abbreviations: HF = headache frequency; HI = headache index; HS = headache severity; mg = milligram; mo = month or months; N = population studied (n = sample size); n.s. = not (statistically) significant; μg = microgram

2

An asterisk denotes a crossover trial.

From: Evidence Tables

Cover of Drug Treatments for the Prevention of Migraine Headache
Drug Treatments for the Prevention of Migraine Headache.
Technical Reviews, No. 2.3.
Gray RN, Goslin RE, McCrory DC, et al.

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