Gabapentin, estrogen, and placebo for treating hot flushes: a randomized controlled trial.
OBJECTIVE
To compare the efficacy of gabapentin, estrogen, and placebo in the treatment of hot flushes.


METHODS
We performed a randomized, double-blind, placebo-controlled trial of 60 postmenopausal women to assess the efficacy of estrogen and gabapentin in the treatment of moderate-to-severe hot flushes. Participants were randomly assigned to receive either 0.625 mg/d of conjugated estrogens (n = 20), placebo (n = 20), or gabapentin titrated to 2,400 mg/d (n = 20) for 12 weeks. Participants recorded frequency and severity of baseline hot flushes on a hot flush diary for 2 weeks before randomization and for 12 weeks after randomization. The primary outcome measure was the weekly hot flush composite score, which takes into account both severity and frequency of hot flushes. Secondary outcome measures were differences in pre- and posttreatment scores pertaining to depression (Zung Depression Scale) and other climacteric symptoms (Greene Climacteric Scale).


RESULTS
Intention-to-treat analysis showed that the reduction in the hot flush composite score for both estrogen (72%, P = .016) and gabapentin (71%, P = .004) was greater than the reduction associated with placebo (54%) at the conclusion of the 12th week. The extent of reduction in hot flush composite score, however, was not significantly different between estrogen and gabapentin (P = .63). No differences were seen between groups in the Zung Depression Scale, or in any of the Greene Climacteric subscales except for the Somatic Symptom cluster, which was significantly greater in the gabapentin arm than in the placebo arm. Despite a lack of group differences in adverse events, the Headache, Dizziness, and Disorientation cluster appeared with greater frequency in the gabapentin group. Estimation of the number needed to harm in this cluster suggests that these symptoms may occur with every fourth patient treated with gabapentin.


CONCLUSIONS
Despite the small scale of this study, gabapentin appears to be as effective as estrogen in the treatment of postmenopausal hot flushes.


BACKGROUND
Clinicaltrials.gov, NCT 00276081.


METHODS
I.
Reddy
Sireesha Y
SY
Department of Obstetrics and Gynecology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA. Sireesha_Reddy@urmc.rochester.edu
Warner
Hiral
H
Guttuso
Thomas
T
Messing
Susan
S
DiGrazio
William
W
Thornburg
Loralei
L
Guzick
David S
DS
D000588:Amines / Q000009:adverse effects / Q000627:therapeutic use*; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D003509:Cyclohexanecarboxylic Acids / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004967:Estrogens / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D000077206:Gabapentin; D019584:Hot Flashes / Q000188:drug therapy*; D006801:Humans; D008593:Menopause / Q000187:drug effects; D008875:Middle Aged; D016896:Treatment Outcome; D005680:gamma-Aminobutyric Acid / Q000009:adverse effects / Q000627:therapeutic use*
D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D004967:Estrogens; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin