Menopausal hot flushes (aka hot flashes) can sometimes be quite serious, causing women to sweat profusely and/or wake up multiple times throughout the night. There may be fresh hope, however, in the form of a new class of drugs that drastically reduces hot flushes in just three days.

In a clinical trial that was published last year, a drug known as MLE4901 was tested on 37 menopausal women aged 40 to 62 years old, all of whom experienced at least seven hot flushes per day. The women were randomly selected to receive a daily dose of either 80 mg of the drug, or of a placebo, for four weeks – after that, they switched to the other tablet for another four-week period.

After recently taking a closer look at the resulting data, scientists from Imperial College London concluded that taking MLE4901 for just three days reduced participants' number of hot flushes by 73 percent. There was also a one-third reduction in the severity of hot flushes, along with an 82 percent decrease in hot flushes interrupting sleep, and a 77 percent reduction in them interfering with the women's ability to concentrate.

It is believed that the drug works by keeping a chemical called neurokinin B (NKB) from activating temperature control areas in the brain. And although MLE4901 itself won't be tested further due to possible side effects on the liver, two very similar drugs have entered larger patient trials. It is hoped that they could ultimately serve as an alternative to hormone replacement therapy, which is commonly used as a treatment for menopause symptoms, but that can also increase the risk of breast cancer and blood clots.

"The potential for this drug class to really improve many of the symptoms of the menopause, such as hot flushes, difficulty sleeping, weight gain, and poor concentration, is huge," says Dr. Julia Prague, first author of the study. "To see the lives of our participants change so dramatically and so quickly was so exciting, and suggests great promise for the future of this new type of treatment."

A paper on the research was recently published in Menopause: The Journal of the North American Menopause Society.