Examining the Evidence
Q Does venlafaxine reduce hot flashes?
<huc>A</huc> Yes. In this well-designed, randomized, placebo-controlled study, extended-release venlafaxine reduced the frequency (but not severity) of patient-perceived hot flashes in healthy postmenopausal women over the 3-month study period. Physicians may consider this therapy when treating women with vasomotor symptoms—especially those who cannot or wish not to take estrogen.
For 12 weeks, Evans et al examined the effect of venlafaxine, a serotonin noradrenergic reuptake inhibitor, on patient-perceived hot flash scores. The authors randomized 80 healthy postmenopausal women with at least 14 hot flashes per week to receive placebo or extended-release venlafaxine 37.5 mg daily for 1 week followed by 75 mg daily for 11 weeks. Sixty-one women completed the study.
Drug effect sustained, placebo effect fades. Both venlafaxine and placebo decreased the hot flash score at 1 month. However, unlike placebo, venlafaxine produced a further drop in hot flashes at 2 months, which was sustained at 3 months. All told, patient-perceived mean hot flash scores dropped 51% from baseline with venlafaxine compared with a 15% drop with placebo. Most women (93%) on venlafaxine planned to continue the treatment after the study concluded.
Confirms previous trials
These findings reinforce data from previous venlafaxine studies, in which an approximately 60% drop in hot flash score was seen with venlafaxine compared with an approximately 30% drop with placebo,1 and add to our knowledge by offering a longer study period. Prior venlafaxine studies included women with a history of breast cancer, as well as those who simply had a fear of the disease.
How does venlafaxine compare with other options?
Fewer sides effects than clonidine, whose side-effect profile limits use in many women, according to a 2004 position statement on vasomotor symptoms from the North American Menopause Society.2 Thus far, research has found venlafaxine to have fewer adverse effects, which include decreased appetite, dry mouth, and initially nausea.
On par with paroxetine. The reduction in hot flashes with venlafaxine 75 mg in this and previous studies is comparable with findings from a study of controlled-release paroxetine, a selective serotonin reuptake inhibitor, at doses of 12.5 mg or 25 mg.3
Probably less effective than estrogen. Evans et al did not directly compare venlafaxine with estrogen, but their findings suggest that venlafaxine is probably not as effective as estrogen for vasomotor symptoms.
1. Loprinzi CL, Kugler JW, Sloan JA, Mailliard JA, et al. Venlafaxine in management of hot flashes in survivors of breast cancer: a randomised controlled trial. Lancet 2000;356:2059-2063.
2. North American Menopause Society. Treatment of menopause-associated vasomotor symptoms: position statement of The North American Menopause Society. Menopause. 2004;11:11-33.
3. Stearns V, Beebe KL, Iyengar M, Dube E. Paroxetine controlled release in the treatment of menopausal hot flashes. JAMA. 2003;289:2827-2834.