ROCHESTER, MinnLow doses of the antidepressant venlafaxine
(Effexor) can reduce hot flashes in breast cancer survivors by 61%,
compared to a 27% reduction with placebo, Charles L. Loprinzi, MD,
told a plenary session of the ASCO meeting. This is a sizable
reduction in hot flashes for women who cant take estrogen
replacement, he added.
Hot flashes, some severe enough to be debilitating, are a major
problem in many postmenopausal women, including cancer survivors in
whom antineoplastic therapy has induced early menopause. Although hot
flashes can be alleviated by estrogen or progesterone preparations,
they are frequently withheld from these women due to concerns about
whether hormones might adversely affect the natural history of breast
The results, from a North Central Cancer Treatment Group (NCCTG)
trial, may also have broader applications. Because it so
clearly works and is reasonably tolerated, use of venlafaxine may be
an option for women without breast cancer who dont want to use
estrogen and/or progesterone medications to alleviate hot
flashes, Dr. Loprinzi observed.
The appearance of this paper in a plenary session represents a
growing maturity in the field of oncology in considering the whole
patient, commented Daniel F. Hayes, MD, of Georgetown
University, Washington, DC, discussant for the session. Dr. Hayes
said that 60% of postmenopausal women report hot flashes, and that
10% to 20% describe them as nearly intolerable.
Daily Diary Kept
The NCCTG study was a four-arm, double-blind, placebo-controlled
randomized clinical trial to evaluate venlafaxine. Women with
bothersome hot flashes (defined as 14 or more episodes per day) were
randomized to 4 weeks of treatment with placebo or with venlafaxine
at doses of 37.5 mg/day, 75 mg/day, or 150 mg/day. Hot flashes were
recorded in a daily hot flash diary used by more than 800 patients in
a series of clinical trials.
The table on page 18 illustrates the percentage of baseline hot flash
scores (calculated by multiplying the number of hot flashes by their
mean severity) during the fourth treatment week as compared to the
Dr. Loprinzi reported that the 37.5-mg/day dose reduced hot flashes
by 40%, and the 75-mg/day dose reduced hot flashes by 60%. The
150-mg/day dose was not significantly more effective than 75 mg/day
at reducing hot flashes and was associated with more toxicity
problems such as mouth dryness, decreased appetite, nausea, and
There were no significant constipation problems on the
75-mg/day arm, Dr. Loprinzi said. Less than 7% of patients
stopped venlafaxine due to toxicity.
Improvements in Libido
Dr. Loprinzi said the researchers also found improvements in
libido in all four study arms, but more marked improvement with
venlafaxine than with placebo. The moral is, if you want an
improvement in your libido, enter an NCCTG hot flash study, he
He concluded that these data definitively support the prestudy
hypothesis that venlafaxine can substantially reduce hot flashes.
This represents a new treatment modality for women with hot flashes.
Dr. Hayes said that the mechanisms that cause hot flashes are not
clear. Estrogen can reduce hot flashes by 50% to 100%, but there is
concern giving estrogen to many cancer survivors. Other treatments
such as vitamin E and dietary soy have shown only marginal efficacy.
It seems reasonable to offer a trial of a selective serotonin
reuptake inhibitor (SSRI) to women or men (such as those being
treated for prostate cancer) who have hot flashes and cannot or do
not choose to take hormonal therapy, Dr. Hayes said.