Scientists at University of Manchester (UoM) are collaborating with a pharmaceutical company, MSD, to develop what is going to be the first anti-tussive drug in the last 50 years. Gefapixant cuts chronic and unexplained cough by two-thirds when taken twice a day.
Cough can occur due to several reasons such as bronchitis and usually resolves on its own or with the help of over-the-counter cough syrups and cold medicines but for reasons unknown to doctors (idiopathic), it may linger on in about 4-10% of people. These people cough for years, sometimes over a thousand times a day and find no refuge in traditional anti-tussive therapy.
Gefapixant is for such people.
Professor Jacky Smith, who is a professor of respiratory medicine at UoM and working on the gefapixant, believes the drug has the potential to treat thousands suffering from idiopathic cough.
The study, published in The Lancet Respiratory Medicine journal this Tuesday, showed that the drug in a small dosage (50mg) effectively arrested or improved cough in majority of the participants. The 12-week trial, which is the largest till date since little or no research has been done on pertussis drugs over the last five decades, consisted of 253 patients, all chronic coughers.
The researchers treated patients with different doses of drug twice a day; low dose (7.5mg) produced a good response and stopped cough in about 52% of the patients; medium dose produced similar results as low dose (52%) but the best response (67%) was obtained when the dose was upped to 50mg.
Gefapixant, if approved and available in the market, will help millions of patients worldwide. It works by acting on the P2X3 receptors on the nerves and calming the throat. An interesting fact about the drug is that it was initially being investigated for its analgesic effects; however, the focus was shifted as soon as the researchers noticed its anti-tussive potential.
The drug is expected to hit the market soon. It is currently in phase III trials which is a step closer to its official approval by the US Food and Drug Authority (FDA). The FDA approves the drug in phase IV after monitoring its clinical efficacy and safety. In phase III, a drug is tested on a large population (3,000 or more people) to determine its safety, effectiveness and dosage. If phase III proves successful, the FDA will most likely sanction the drug.
Whether gefapixant will be a prescription or over-the-counter drug is too soon to tell. Even professor Smith is not sure but he knows for a fact that the drug can make a big difference for people suffering for chronic refractory cough.
When Health Units approached Dr. Ahmad Hassan, a PhD scholar in pharmacology, about the potential new drug and its efficacy, he sounded hopeful about the prospect:
“Gefepixant has shown tremendous results in arresting cough within 12 weeks. This is a clinical success because when cough goes from bad to worse, it becomes increasingly challenging for the doctor to control it, let alone treat it,” he said, adding, “However, further research is warranted before gefapixant can be safely prescribed in chronic cough.”