Treating hot flashes - without hormones

Summarized by Robert W. Griffith, MD
February 5, 2001 (Reviewed: February 18, 2003)

Just about any woman entering the menopause will experience the discomfiture of hot flashes. If she goes to her physician, she'll probably be given a prescription for hormone replacement therapy (HRT) using an estrogen. Estrogens are not without risk, and should not be taken by women who have had breast cancer. Many women, in fact, prefer a 'natural', or non-hormonal approach. This means they may turn to widely advertised dietary supplements or herbs; in fact, many of the effective ones contain a form of estrogen derived from plants - these are known as phytestrogens.

Entirely non-hormonal approaches to the treatment of hot flashes include vitamin E, a blood pressure lowering drug - clonidine, another, older, blood pressure drug - methyldopa, and derivatives of the belladonna plant.

Sometimes antidepressant drugs are used, especially the newer SRI (serotonin reuptake inhibitor) agents, such as Prozac. Now a report has been published of the effectiveness of a new antidepressant drug, venlafaxine, in treating hot flashes.

The study, which was coordinated by physicians at the Mayo Clinic, USA, enrolled women who had a history of breast cancer, or who wished to avoid taking estrogens for some reason. They had to have hot flashes at least twice a day, which had been present for at least a month. They were assigned to receive one of three different dose levels of venlafaxine, or a dummy treatment (placebo). The venlafaxine doses at the end of the 4-week period were 37.5 mg, 75 mg, and 150 mg daily. Participants completed a daily diary of their hot flashes for a baseline week, and continued with this through the study. Once a week they answered questions about their 'quality-of-life', and completed a depression test using a recognized list of possible symptoms.

229 women enrolled in the study. There were some dropouts, leaving between 43 and 50 women in each of the 4 treatment groups. After 4 weeks of treatment, all the groups had a reduction in their 'score' for hot flashes. (The score was made up of the total number and the severity of the hot flashes.) 20% of the women taking the placebo reported a reduction of more than 50% in their hot-flashes scores, while the 3 drug-treatment groups had reductions of 45%, 63% and 55% for the 37.5 mg, 75 mg and 150 mg doses, respectively. Average hot flashes scores were reduced from baseline by 27% in the placebo subjects, and by 37%, 61% and 61% for the 3 venlafaxine groups.

There were some side effects of venlafaxine in the first week, which persisted in those taking the higher doses throughout the four-week study period. These were described as 'manageable' -- nausea, dry mouth, loss of appetite, and constipation. Sex drive (one of the questions in the depression test) increased in all 4 groups, but with slightly greater improvements in the venlafaxine groups, compared with placebo. Depression scores improved in a similar way - more with venlafaxine than with placebo - though the differences were not significant. The overall quality-of-life increased by an average of three points in the each of the 3 venlafaxine groups, and decreased by three points in the placebo group.

These results show that venlafaxine was able to relieve the symptoms of hot flashes effectively and quickly. Side effects were generally tolerable. The extent of the improvement with placebo was the same as that reported in other studies, and the improvement with venlafaxine was similar to that with other hormonal and non-hormonal treatments. As there was no significant effect on depressive symptoms, it seems likely that the way the drug works in reducing hot flashes is distinct from its antidepressant action.

It may be possible that the breast cancer patients were a group particularly suited to management by an antidepressant. Before venlafaxine is used widely to treat hot flashes, it might be better to wait for larger studies in postmenopausal women with no history of breast cancer. If these turn out positive, women everywhere will be pleased to have available another non-hormonal treatment that is effective for this distressing complaint.

The use of hormone replacement therapy must be reconsidered in the light of recent findings from the Women's Health Initiative Study. The potential risk of breast cancer and other side effects has been determined fairly conclusively - see "Hormone Replacement Therapy (HRT) - Now What to Do?" (Robert Griffith, editor)

Source

• Venlafaxine in management of hot flashes in survivors of breast cancer: a randomised controlled trial. CL. Loprinzi, JW. Kugler, JA. Sloan, Lancet, 2000, vol. 356, pp. 2059--2063

Related Links
Menopause - Complementary Medicine
The Novartis Journal Pathways: Facing 'the change'

Please take a moment to give us your comments. For questions about Health matters you may check our "Questions & Answers" Portal and Service.