A new drug to treat chronic coughs could be a “gamechanger” treatment for the thousands of Britons who cough uncontrollably, many times a day.
Prof Surinder Birring, a leading lung doctor, has led a global trial that found gefapixant reduces a person’s coughing by up to 60% and brings some relief to 70% of those who take it.
Birring, a professor of respiratory medicine at King’s College hospital in London, said that if it gained approval the experimental drug would be the first new treatment for more than 50 years to alleviate the symptoms of the debilitating condition.
A chronic, or persistent, cough is defined as one that lasts for more than eight weeks. Between 4% and 12% of people in the UK suffer from it, lung specialists estimate. In many cases that is because they have asthma, chronic obstructive pulmonary disorder or another condition that seriously affects their breathing. But in others their cough has no obvious medical explanation.
“If gefapixant becomes available it could be a gamechanger in respiratory medicine,” Birring told the Guardian. “It’s a very effective treatment that works in most patients with chronic cough. It was found to be safe and effective in the clinical trial. It’s a major advance in the field of cough.
“It could be the first new drug to be approved for over 50 years. There’s potentially thousands and thousands of patients who would be suitable to receive this treatment.”
Chronic cough sufferers often have a very limited social life because they avoid gatherings in case their constant coughing irritates people around them. Many also become anxious, depressed, or both. It can disrupt someone’s sleep and cause them to cough so much that they end up with muscle and rib pain. Some people also faint, vomit or get headaches as a result of coughing so much.
“We found that there was a 60% reduction in cough frequency with gefapixant. People slept better, had fewer chest pains, were less tired and better able to go about their lives. It led to a clinically significant improvement in their quality of life in around 70% of patients receiving gefapixant. It’s very good news for patients,” Birring added.
The drug has been approved in Japan, where it is already available to patients, and has been registered in Switzerland where its manufacturer, Merck Sharp & Dohme, is working towards launch. The Food and Drug Administration in the US has started examining the drug. It would have to be licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) before people in the UK could access it.
Birring was the chief investigator of one of two international trials of the drug undertaken in 20 and 17 countries respectively – including the UK – and involving over 2,000 patients. In the trials participants were given either 15mg or 45mg of gefapixant twice a day or a placebo.
The patients taking part all had a “refractory” – or unexplained – chronic cough. Two-thirds of those with chronic cough are women, and it often does not strike until someone is in their 50s.
The researchers found that taking two 45mg doses brought about “significant reductions in 24-hour cough frequency” when compared with those given the placebo, according to the results, which were published earlier this year in the medical journal the Lancet.
Birring explained that chronic cough was caused by hypersensitivity of the sensory nerves in their airways, which can be stimulated by temperature, humidity or air pollution.
Half of trial participants either found their ability to taste was either affected, or disappeared altogether, when they were on the drug. However, most decided that that side-effect was “a price worth paying” for the big decline in the amount they coughed, Birring added.
The charity Asthma and Lung UK welcomed the results of the trials. “This promising research could pave the way for the development of a new treatment for chronic coughs,” said Dr Erika Kennington, its head of research and innovation.
“Many will have experienced a bad cough for a few days or weeks. But other people have persistent coughs even when no cause for this has been found after extensive investigation.
“Some people struggle to sleep through the night without waking up coughing and can even cough so violently it causes serious rib and muscle pain.”
New treatments for people with long-term respiratory symptoms emerge only rarely, because the government funds too little research into such conditions, she added.
‘I cough 45 times an hour – I want some peace’
Patty Harris, a singer, who is 64, describes how seriously the chronic cough she has had for 27 years affects her life.
My persistent cough began in 1995. I had a dose of flu then and the cough that I developed then never went away. It’s a pain, really. King’s College hospital in London, where I am a patient, have measured how often I cough and it turns out that I cough 45 times an hour, or about 660 times a day, although not at night.
It’s not very nice coughing all the time. It affects my day to day life, about eight or nine out of ten, I would say. It’s very distressing and it’s also very tiring to cough all the time like this. Persistent cough is a very frustrating condition.
It’s also tedious because you can’t do anything that other people do, like go to the cinema or theatre, in case your coughing disturbs people. So I have a very restricted social life. If I do go to a film or play I always book a seat on the end of a row, in case I have to leave. When I do go to a restaurant, if I eat anything pungent, like a curry or anything with chilli in it, the first mouthful of it sets me off coughing, which is very embarrassing.
The only way I can suppress my cough is by using strong painkillers, though that’s not foolproof. So if I’m performing – I’ve been a singer all my life – I take two co-codamol tablets an hour before I go on stage. I sometimes have some alcohol with it too, as that can also help to suppress the cough. But if I do that then I pay a price the next day as I often feel sick and nauseous.
It could be worse. I know some people who never leave their house because their cough is so bad. That’s so sad.
I read all the medical papers about cough and potential treatments because I’m desperate to find something that helps me. I want some peace before I die! I want to be able to go out somewhere and not be embarrassed and not have to dose myself up to the eyeballs with painkillers. I’ve tried various treatments, including epilepsy drugs, but they’ve not helped.
I hope that gefapixant and some of the other drugs for chronic cough that are being trialled just now work out. People like me are desperate for a treatment that actually works.”
As told to Denis Campbell