All about chronic cough hypersensitivity syndrome

Chronic cough hypersensitivity syndrome (CHS) is a condition characterised by a persistent cough that lasts more than eight weeks, often triggered by low-level stimuli such as talking, laughing, or exposure to irritants. Traditional treatments, including inhaled corticosteroids or antitussives, often fail to provide relief, leaving patients with a significantly reduced quality of life.

Gefapixant, a novel therapeutic agent, offers new hope for those suffering from CHS. It is a selective P2X3 receptor antagonist that works by blocking ATP-mediated signaling in sensory nerves responsible for cough reflex hypersensitivity. In patients with CHS, heightened sensitivity of these nerve pathways leads to excessive coughing in response to otherwise non-irritating stimuli.

Clinical trials have demonstrated that gefapixant significantly reduces cough frequency in patients with refractory or unexplained chronic cough. In Phase III studies (COUGH-1 and COUGH-2), patients taking gefapixant experienced a substantial decrease in 24-hour cough counts compared to placebo. While the drug is generally well-tolerated, taste-related adverse effects—such as dysgeusia or ageusia—have been the most commonly reported side effects.

The introduction of gefapixant represents a shift from symptom-suppressing therapies to mechanism-targeted treatment. By addressing the underlying neural hypersensitivity, it provides a more rational and effective approach for managing chronic cough. This is particularly beneficial for patients who have exhausted other treatment options without relief.

Although not yet approved in all markets, gefapixant has been authorized in several countries for use in adults with refractory or unexplained chronic cough. As more data becomes available and awareness grows, gefapixant may soon become a cornerstone in the management of chronic cough hypersensitivity syndrome, transforming care for patients long underserved by current therapies.