Mayo Clinic researchers report on effectiveness of treatments for hot flashes


Findings presented at American Society of Clinical Oncology (ASCO)

ROCHESTER, Minn. -- Mayo Clinic researchers, working with North Central Cancer Treatment Group (NCCTG) investigators, will present new study findings about treatments to reduce hot flashes in women. The research will be outlined during the 2005 American Society of Clinical Oncology (ASCO) Annual Meeting, May 13-17 in Orlando, Fla.

EMBARGOED: Hold for release until after presentation at the 2005 American Society of Clinical Oncology (ASCO) Annual Meeting, Abstract # 8013; Sunday, May 15, 2005, 8 a.m. EDT

Mayo Researchers Evaluate Black Cohosh

Mayo researchers will present new data showing evidence that black cohosh does not reduce hot flashes in women any better than a placebo. Used extensively in Europe for treating hot flashes, black cohosh (Cimicifuga racemosa) is an herbal remedy derived from a plant native to North America and a member of the buttercup family.

The black cohosh study findings should help patients and their physicians look for other methods that can help control the common symptoms in women during menopause.

"The findings demonstrated absolutely no improvement of symptoms when women took black cohosh compared to placebo," says surgeon Barbara Pockaj, M.D., of Mayo Clinic in Scottsdale, Ariz., the lead physician in the study. "This finding is extremely important, because we can now say to our patients that black cohosh does not work and we have to try other methods to control their symptoms."

The double-blind, randomized study involved 132 women divided into two groups. One group took black cohosh pills for one four-week period and then a placebo for one four-week period. The other group took a placebo during the first four weeks, followed by the black cohosh. Participants in the study kept a daily hot flash diary during a baseline week and during the eight-week cross over treatment period. They kept track of the daily number of hot flashes and hot flash scores (measured by assigning points to each hot flash based on severity and then adding the points for a given time period).

Mayo researchers measured patient treatment preferences after completion of both treatment periods by ascertaining which treatment period, if any, the patients preferred: 34 percent of patients preferred the black cohosh treatment, 38 percent preferred placebo and 28 percent did not prefer either treatment.

As many as three out of four women in the United States experience hot flashes during menopause. Hot flashes occur in women with varying frequency and severity, causing frequent sleep interruptions that can affect a woman's mood or overall health. Certain surgical or medical treatments for cancer can cause menopause to begin earlier and more suddenly than it would normally occur; so, many women undergoing treatment for cancer must also cope with hot flashes.

Researchers say that hot flashes appear to be triggered by changes in a woman's brain chemistry that result from decreased estrogen levels as she approaches menopause.

There are other non-estrogenic treatments for hot flashes that researchers have identified that do work. Women and their physicians should talk about what treatment options are available and what might work best with the individual patient, says Dr Pockaj. DISCLOSURE: This trial was sponsored by a grant from the National Cancer Institute and conducted by a network of researchers led by the NCCTG. Drug supply for the study was provided by Hi Health. Based at Mayo Clinic in Rochester, Minn., NCCTG is a national clinical research group sponsored by the National Cancer Institute. NCCTG is a network of more than 400 community-based cancer treatment clinics in the United States, Canada and Mexico that work with Mayo Clinic to conduct clinical studies for advancing cancer treatment.

EMBARGOED: Hold for release until after presentation at the 2005 American Society of Clinical Oncology (ASCO) Annual Meeting, Abstract # 8014; Sunday, May 15, 2005, 8 a.m. EDT

NCCTG Study Compares Venlafaxine and Progestational Agents in Reducing Hot Flashes

Mayo Clinic researchers will outline current data comparing the effectiveness of two medicines -- venlafaxine and a progestational agent -- in combating hot flashes.

Previous studies have shown that both venlafaxine and progestational agents substantially decrease hot flashes. This NCCTG trial demonstrated that a single dose of the progestational agent, medroxyprogesterone acetate (MPA), alleviated hot flashes more than did the daily use of the oral antidepressant venlafaxine (Effexor). Three to four weeks after treatment began, researchers observed that MPA was more effective than venlafaxine. This difference became even more striking after six weeks of treatment, says Mayo medical oncologist Charles Loprinzi, M.D., the NCCTG study's lead investigator.

"This improved hot flash benefit appeared to last for at least six months following a single MPA dose, with almost three times as many patients still reporting a 90 percent hot flash reduction following MPA versus patients receiving daily oral venlafaxine," says Dr. Loprinzi.

The findings reviewed in this presentation include data from 185 patients. Six weeks after treatment was started (compared to the baseline week), patients who received the single shot of MPA, versus those on venlafaxine, had greater reductions in median hot flash frequencies (85 percent vs. 52 percent reduction) and reductions in median hot flash scores (88 percent vs. 57 percent reduction).

Mayo researchers also noted that 24 percent of patients who received MPA reported no hot flashes after six weeks compared to 1 percent of venlafaxine patients. Patients on MPA also reported less trouble sleeping, less sleepiness, less constipation, less abnormal sweating and less hot flash distress than patients on venlafaxine.

The patients on venlafaxine had trends for less trouble than MPA patients with "controlling their feelings," less "feeling tense," and less "stress." Because the trial included participants with and without a history of breast cancer, these findings should benefit a very broad group of women experiencing difficulties with hot flashes.

Dr. Loprinzi and his colleagues note that recent reports of large clinical trials linking hormone therapy to an increased risk for cancer have caused concern about the use of estrogen therapy, given with or without progesterone.

"Given that it has taken tens of thousands of women, studied for decades, to understand the safety of estrogen or combined hormonal therapy, further definitive data regarding a single MPA dose is not likely to become available in the foreseeable future," says Dr. Loprinzi. "Therefore, decisions regarding whether to use, or not use, MPA for hot flashes will need to be made with less than definitive data. Available information suggests that a single 400 mg dose of MPA is safe and is a reasonable option to offer patients."

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Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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