Antidepressants for Hot Flashes Pass Sexual Function Hurdle

Kate Johnson

October 15, 2013

DALLAS — Modest improvements in sexual function and sleep with estradiol and the antidepressant venlafaxine (Effexor XR, Pfizer) are among the secondary findings of the newly released MsFLASH 3 study.

"We just see small improvements, but that's reassuring," said lead investigator Andrea LaCroix, PhD, from the Center of Excellence in Women's Health at the University of California, San Diego.

Dr. LaCroix noted that she sees a "paradigm shift" in the new choices that have opened up for treatment of menopausal symptoms.

The results were presented here at the North American Menopause Society (NAMS).

The effectiveness of estradiol, venlafaxine, and escitalopram in the treatment of vasomotor symptoms was found to be similar in MsFLASH 3 and a pooled analysis of previous MsFLASH studies, as reported by Medscape Medical News. This means that treatment decisions will likely be made on the basis of other details, such as effects on sleep and sexual function.

We just see small improvements, but that's reassuring.

In the newly released MsFLASH 3 trial, "no medicine really stands out as the clear winner on sleep. For sexual function, there are small benefits in desire with estrogen, and venlafaxine was associated with decreased pain but increased interference with orgasm," Dr. LaCroix said.

Low-dose paroxetine mesylate (Brisdelle, Noven Therapeutics) — the serotonin-reuptake inhibitor that was recently approved by the US Food and Drug Administration for the treatment of vasomotor symptoms — is another option. In a separate study presented here at NAMS, it was found to cause no weight gain or negative changes in sexual function.

"These data should be reassuring to menopausal women and clinicians considering the use of low-dose paroxetine to treat bothersome hot flashes," said lead investigator Andrew Kaunitz, MD, from the University of Florida College of Medicine in Jacksonville.

"Based on experience with the administration of higher doses of SSRIs, concerns regarding the possibility of weight gain and sexual side effects with these agents are legitimate," he told Medscape Medical News.

The double-blind randomized placebo-controlled MsFLASH 3 trial compared 8 weeks of low-dose oral 17-beta-estradiol 0.5 mg/day (n = 60), extended-release venlafaxine 75 mg/day (n = 54), and placebo (n = 95).

It's wonderful to have something else for women who cannot or do not want to take hormone therapy.

There were no significant differences between the 3 groups in changes on the composite Female Sexual Function Index (FSFI) score or Female Sexual Distress Scale, reported Susan Reed, MD, from the University of Washington School of Medicine in Seattle.

However, on the desire domain of the FSFI, estradiol was better than venlafaxine (P = .04), and on the anorgasmia domain, venlafaxine was better than estradiol (P = .04).

Venlafaxine was also slightly better than estradiol on reduction of pain (P = .04) and vaginal dryness (P = .006).

Both medications showed modest but significant improvements in sleep, with decreases in insomnia and increases in sleep quality. However, "despite the statistically significant finding, the absolute difference was small," said Dr. Reed.

The study of low-dose paroxetine mesylate (7.5 mg/day) analyzed pooled safety and efficacy data for almost 1200 patients. The researchers measured sexual function with the Arizona Sexual Experiences Scale and the Hot Flash Related Daily Interference Scale sexuality subscore.

There were "no clinically meaningful or statistically significant changes from baseline" in weight or sexual function over 24 weeks, Dr. Kaunitz reported.

"Observations based on longer-term use of this formulation — the first nonhormonal agent approved for treatment of hot flashes — may become available in the future," he told Medscape Medical News.

"It's wonderful to have something else for women who cannot or do not want to take hormone therapy," said Margery Gass, MD, executive director of NAMS.

"We always have to tailor treatment to the woman's priorities and personal needs," she told Medscape Medical News. The appeal of antidepressants is that their effects are different than hormonal therapies, she added.

"Some help depression, some help chronic pain. There are a lot of things going on in the brain that can benefit from some of these products, and no one product is perfect for every woman," Dr. Gass noted.

The MsFLASH study was supported by the National Institutes of Health. The MsFLASH investigators and Dr. Gass have disclosed no relevant financial relationships. Dr. Kaunitz reports that his institution received support from Noven Pharmaceuticals for participating in the trial.

North American Menopause Society Annual Meeting. Presented October 10 and 11, 2013.


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