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|Date: June 15, 2005||HC# 030552-282|
Re: Pilot Study Evaluates Black Cohosh Use in Treating Hot Flashes
Pockaj B, Loprinzi C, Sloan J, et al. Pilot evaluation of black cohosh for the treatment of hot flashes in women. Cancer Invest. 2004;22(4):515-521.
Hot flashes can be a significant clinical problem in women with diminished ovarian function as a result of menopause or breast cancer treatment. Hot flashes, described as episodes of excessive sweating and flushing of the skin, have been treated historically with estrogen. However, because of the link between estrogen use and the possible development of breast cancer, the use of estrogens is contraindicated in women at high risk or those already diagnosed with breast cancer. Nonhormonal therapies such as clonidine, methyldopa, and belladonna alkaloids have had limited success in the treatment of hot flashes. Many patients with cancer, especially breast cancer, have reported an increased use of alternative therapies for menopausal symptoms.
Black cohosh (Actaea racemosa syn. Cimicifuga racemosa) is an herbal remedy that has been used to treat menopausal symptoms. Data from several small trials on black cohosh suggest that this herb has potential clinical benefit (without any evidence of hormonal stimulation) in women who experience hot flashes. The purpose of this pilot trial was to estimate the effectiveness of black cohosh in the treatment of hot flashes and to evaluate the results as a basis for justifying a larger randomized trial.
Participants of the open and uncontrolled trial (n=23, n=21 completed the study) were women who were considered to be at high risk or who had a history of breast cancer (n=13) but were currently cancer free. These women reported significant incidence of hot flashes (at least 14 per week). Black cohosh was given in the form of the commercial product Remifemin® (Schaper & Bruemmer, GmbH & Co. KG, Salzgitter, Germany, 1 tablet orally twice a day). The first week was a baseline period, and therapy was given for the subsequent 4 weeks. Hot flash data were collected by daily questionnaires during baseline and treatment weeks.
Patients reported an average of 8.3 hot flashes per day (range 3.7-18.9) during the baseline week. At the completion of the 5-week study, the reduction in mean daily hot flash frequency was 50% (95% CI, 34%-65%; mean 4.2; range 0-18.1), while weekly hot flash scores were reduced 56% (95% CI, 40%-71%). Overall, patients reported less trouble with sleeping, less fatigue, and less abnormal sweating. No patients stopped therapy because of adverse effects. In addition, using in vitro techniques, the authors found that black cohosh did not demonstrate estrogenic activity (transcriptional-activation assays in yeast.
Black cohosh appeared to reduce hot flashes and have a low toxicity. Due to the lack of systematic estrogenic activity black cohosh seems to be suitable for patients who are considered to be at high risk, e.g., history of breast cancer. Previous studies suggest that a reduction of hot flash activity of at least 45% in a pilot trial merits conducting a large randomized trial. The authors suggest that the current pilot trial satisfies this criterion, since the observed reduction of hot flash activity with this black cohosh therapy was 56%. "These results suggest that further evaluation of this black cohosh preparation with a Phase III randomized trial is indicated," conclude the authors. In summary, this pilot study supports the hypothesis that black cohosh decreases hot flashes in women with breast cancer, premalignant breast diseases, and/or an antipathy to estrogen therapy.
—Heather S. Oliff, PhD