Balance app founder Dr Louise Newson unpicks recent headlines around hot flush drug fezolinetant
You may have seen the news this week that UK medicines regulator NICE is in the final stages of recommending drug fezolinetant to treat hot flushes in menopausal women.
The announcement that the drug could soon be available on the NHS has been met with overwhelmingly positive headlines. ‘Half a million women eligible for NEW blockbuster menopause drug after it’s given NHS green light’ screams one. ‘New tablet could tackle hot flushes and night sweats for half a million women’ says another.
As a physician, and as a woman who knows firsthand the impact of low hormones, these headlines trouble me for a number of reasons.
More than hot flushes
While fezolinetant is being touted as an alternative to hormone treatment, it’s worth remembering that it will only target hot flushes and night sweats (also known as vasomotor symptoms). Symptoms which, contrary to the stereotypical image of menopause, aren’t the most common.
Let me give you an example. Out of 131 million symptom logs on my free Balance app, the most common symptom recorded is brain fog, followed by anxiety and low mood. The most severe symptoms are feeling tired, low libido and tinnitus.
And what about hot flushes and night sweats? Hot flushes were number 10 most commonly recorded, while night sweats were 34th most common.
I’m not minimising the impact of vasomotor symptoms, but in my clinical experience, menopause is far from a single-symptom issue. Women tend to experience several symptoms, both physical and psychological. We need to be looking at the whole-body impact of low hormones, and we already have a tried, tested and cost-effective treatment that works: hormones.
Lack of data
Fezolinetant has not been directly compared in studies to HRT – the gold standard for treating menopausal hot flushes – nor has it been compared with other non-hormonal treatments either.
More worrying for me is the lack of evidence on long term (more than one year) efficacy and safety, and this drug has not been tested on all ages of menopausal women.
Women receiving treatment for cancer, including breast cancer, have not been included in any long term clinical studies, and fezolinetant is not currently recommended for use in women with current breast cancer, or liver disease, as the safety and efficacy are unknown.
Potential wider effects
Hot flushes and night sweats are thought to be caused by increased activity in certain brain cells called KNDy neurons, which are involved in controlling body temperature. These neurones are located in a part of your brain called the hypothalamus, which helps regulate hormones and your menstrual cycle.
When levels of hormones such as estradiol fall or fluctuate, these KNDy neurons can become more active. This can make the brain’s temperature control system more sensitive, which may trigger hot flushes and night sweats.
Fezolinetant works by blocking a specific receptor called the neurokinin-3 receptor, which helps transmit signals from KNDy neurones. By blocking this receptor, this drug reduces the activity of these neurones and may help relieve hot flushes.
However, neurokinin receptors are not only found in the hypothalamus: they also exist in other parts of your brain, your spinal cord, and in organs such as your ovaries and womb, as well as in your digestive, cardiovascular and immune systems. Because of this, blocking these receptors is likely to affect other body functions. And importantly, the full effects of blocking them throughout the body are not yet completely understood.
Fezolinetant also blocks a protein called kisspeptin which has many beneficial effects in your body. It can work to stop cancer spreading. It also works to increase amounts of progesterone, estradiol and testosterone in the brain so blocking it leads to even lower levels of these hormones in your brain.
Menopause societies and many menopause specialists worldwide are paid by companies who make neurokinin receptor blockers – it is important that information about new drugs is impartial and based on evidence.
Not addressing long-term risks of low hormones
NICE states that fezolinetant can be used when hormone treatment is not recommended, for example in in cases of deep vein thrombosis or pulmonary embolism. However, body identical hormones do not increase risk of clot so can be prescribed in women who have had a clot in the past.
It makes no sense to consider non-hormonal treatments as first line for these women.
Crucially, fezolinetant won’t address the health risks associated with menopause. It won’t improve bone density, reduce inflammation and protect our brains and cardiovascular system from the effects of low hormones. Only by correcting the hormone deficiency with natural, body identical hormones will do this.
There are risks to both symptoms and future health if hormone treatments (containing progesterone, estradiol and testosterone) are not prescribed to women. Women should have more education and knowledge about this.
It’s easy to take headlines at face value, but I firmly believe every woman has the right to work with their healthcare team on finding a treatment that is right for them, rather than closing the door on hormones to half a million women.
