Anti-depressant “relieves hot flushes in more than half of menopausal women”
Venlafaxine improved flushing in over 60 per cent of patients. However, it is known to cause withdrawal symptoms
Hot flushes suffered by menopausal women may be caused by abnormalities in the function of blood vessels and could be treated with a type of anti-depressant, say researchers.
The flushes affect more than 75 per cent of women going through the menopause and leave some unwilling to leave the house.
Hot under the collar: The anti-depressant venlafaxine improved flushing in over 60 per cent of patients. However, it is known to cause withdrawal symptoms
Wellbeing of Women, a charity which funded the study, hopes the findings could lead to new treatments for the problem, offering an alternative to Hormone Replacement Therapy (HRT).
Under normal circumstances, if the body temperature rises, the blood vessels under the skin dilate in order to lose heat, leading to reddening of the skin and sweating.
In women with hot flushes, this can occur at the smallest provocation or seemingly for no reason at all.
Mary Ann Lumsden, Professor of Medical Education and Gynaecology at the University of Glasgow, believes patients who experience severe hot flushes may actually have an abnormality in the function of the blood vessels.
She compared women who experience hot flushes with those who do not, studying the peripheral blood vessels in patients” arms.
Until now, doctors have worked on the assumption that the brain is responsible for hot flushes.
When over-heating occurs, it sends signals to the body to “lose heat” by dilating blood vessels and producing sweat.
However, Prof Lumsden”s new findings suggest abnormalities in the blood vessels themselves may also contribute to the overactive response seen in many menopausal women.
She said: “My team and I have found that the blood vessels of women who get hot flushes dilate much more easily than those that don”t, and that they became less “reactive” when a drug such as serotonin is prescribed.
“What”s fascinating is that it appears to be the blood vessels themselves rather than what goes on in the brain that actually causes hot flushes.”
She added: “We”ve recently done some brain scanning but don”t yet have the results and this should clarify the situation further.
“If we can decrease the reactivity of blood vessels with newer treatments that have fewer side effects than HRT then we can make substantial leaps forward.”
The researchers also found that patients who are prone to hot flushes have more risk factors for heart disease.
As part of the research, the scientists treated 134 female patients with drugs known to decrease the number of hot flushes.
They were divided into groups of between 30 and 40, with a control group of 15.
Some were given the anti-depressant venlafaxine, which is designed to boost levels of serotonin, the so-called “happiness hormone” active within the brain and also in the blood vessels elsewhere in the body.
Others were given clonidine – a drug typically used to treat high blood pressure – and others HRT while the control group were given a placebo.
HRT was found to be the most effective treatment, with 75 per cent noting an improvement, while venlafaxine improved flushing in over 60 per cent of patients – with the majority of those prescribed it wishing to continue with the drug. Clonidine only worked in 40 per cent of the women.
However, if a patient suddenly stops taking venlafaxine they can experience significant withdrawal symptoms including anxiety, low mood, insomnia and nausea.
Prof Lumsden concluded that serotonin has a key impact on blood vessel function and said it should be investigated further.
The research has been carried out over the last four years.