Venlafaxine, one of the newer antidepressant drugs,
alleviates hot flashes in about 60 percent of breast cancer survivors and
other women with postmenopausal symptoms, according to a new study conducted
by the North Central Cancer Treatment Group, a clinical trials cooperative
group based at Mayo Clinic.
The study will be published in the December 16 issue of The Lancet. This
study was orally presented at the American Society of Clinical Oncology
meeting in New Orleans, La., on May 21, 2000.
"The results seen with venlafaxine represent the most effective nonhormonal
treatment reported to date for alleviation of hot flashes, which are a major
clinical problem for many breast cancer patients and other postmenopausal
women," says Charles Loprinzi, M.D., a Mayo Clinic medical oncologist and
the principal investigator of the study. "Given that we studied three
different doses, we also now know what dosage produces the optimal effect:
an initial daily dose of 37.5 milligrams, to be increased to a maximum of 75
milligrams daily as needed."
Hot flashes can be a significant complaint for women experiencing diminished
ovarian function as a result of menopause. Hot flashes may be particularly
problematic for women who have had breast cancer. A commonly prescribed oral medication for breast cancer, tamoxifen, has been found to cause hot flashes. Hot flashes also may occur as a result of chemotherapy, which may induce a
In addition, many women suffering hot flashes reject estrogen therapy that
might bring relief, due to concern that estrogen might promote breast
cancer. A previous North Central Cancer Treatment Group study demonstrated
that megesterol acetate is an effective nonestrogenic treatment for women
with this concern, reducing hot flashes by 80 percent. Nonetheless,
megestrol acetate is a female hormone derivative (progesterone), and some
patients and physicians are reluctant to use any hormone product in women
with a history of breast cancer.
Thus, the search for a viable nonhormonal method for alleviating hot flashes
ensued, including previous North Central Cancer Treatment Group studies of
vitamin E as well as clonidine, a blood pressure medication. Results from
these studies, however, were less than satisfactory. "Nonhormonal means
tested to date have limited efficacy and/or bothersome side effects which
limit their utility," says Dr. Loprinzi.
Anecdotal reports of hot flash alleviation during venlafaxine treatment for
depression prompted its consideration as a hot flash treatment. After a
pilot study conducted at Mayo Clinic provided additional data suggesting
this drug's effectiveness in remedying hot flashes, the North Central Cancer
Treatment Group investigators undertook the current larger study.
This current placebo-controlled clinical trial evaluated three different
doses of venlafaxine. The trial involved 229 patients, the majority of whom
had a history of breast cancer. All of the women had bothersome hot flashes,
with at least 14 hot flashes per week. Patients in the trial completed daily
diary hot flash questionnaires for a baseline week and during the four-week
treatment period. The dose of venlafaxine discovered to be optimal in this
trial (37.5 mg/day for one week, then increasing this to 75 mg/day) reduced
hot flashes by 61 percent, compared to a 27 percent reduction in hot flashes
seen in patients receiving placebo.
This drug was well tolerated by most patients. Side effects at this dose,
including mouth dryness, appetite suppression and nausea, were seen in a
minority of patients. In most patients, the nausea was a temporary problem
that generally resolved after a couple of weeks.
The study investigators also noted that patients' overall quality of life,
measured by two quality-of-life questions before and after treatment, mildly
increased at the end of the study for patients taking any dosage of
venlafaxine compared to those taking placebo. In addition, the investigators
found that venlafaxine doses of 37.5 to 150 milligrams per day did not seem
to cause problems with libido when measured during the four weeks of
therapy. Decreased libido recently has been reported as a side effect of
some of the newer antidepressant drugs.
Hot flashes are described by patients as a transient episode of flushing,
sweating and a sensation of heat, often accompanied by palpitations and a
feeling of anxiety, and sometimes followed by chills. Hot flashes can be
very disruptive to life. Patients describe anxiety-producing hot flashes
with sweat requiring changes of clothing and bedding, disruption of sleep
and a general diminishment of mental and physical quality of life.