Two trials of a new drug, referred to as Gefapixant, has shown at low doses to ease distressing symptoms of a chronic cough with very little side effects.
Chronic coughing is thought to affect between 4-10% of the population, which can be caused by several factors such as asthma, gastroesophageal reflux disease, pneumonia, bronchitis and postnasal drip.
Researcher Jacky Smith, a Professor of Respiratory Medicine at the University of Manchester and consultant at Wythenshawe Hospital, said: “This drug has exciting prospects for patients who suffer from the often distressing condition of chronic cough”.
Although the drug can reduce the sense of taste at high doses, up to 50mg the effect of the drug does not impair senses. The study, published in Lancet Respiratory Medicine Today, shows that in a 12-week trial of 253 patients, 80% of patients had a clinically significant response to a dose of 50mg.
Results showed that a dose of 7.5mg reduced the coughing by 52%, 20mg by 52% and 50mg by 67% from baseline. However, around a quarter did not respond to the drug.
Both studies were randomised and double blinded, which means that none of the participants knew who received the treatment. The drug is now in two larger, global phase 3 trials, carried out to confirm and expand on the safety and effectiveness results from previous research.
This new trial is significant because no effective treatments for coughs have met clinical needs, and no new therapies have been approved in the last 50 years, says Professor Smith.
Interestingly, the drug was initially developed as a pain killer, until the researchers discovered it impacted chronic cough quite significantly. Gefapixant targets P2X3receptors in the nerves which control coughing, which was what the team monitored to see the drug’s impact.
Professor Smith added: “We can’t yet say when or if this drug will be available on prescription, however, if the phase 3 trial is successful then it would certainly be a major step towards everyday use”.
Chronic cough can greatly impact someone’s everyday life. Retired journalist Nick Peake from Warrington, has been suffering for 25 years from the debilitating condition. He said: “Coughing has blighted my life: every day without fail I cough for the first two hours…it wears me out…I’m thoroughly fed up with it and desperate for a cure to be found”.