Efficacy of Gefapixant, a P2X3 Antagonist, for Refractory Atopic Cough

Abstract: Cough, a frequent symptom encountered in clinical practice, often has a considerable impact on patients’ lives. There is an urgent need to investigate more potent antitussive treatments for chronic refractory cough, particularly atopic cough, which is a major cause of chronic refractory cough in Japan. Previous studies have shown that eosinophilic tracheobronchitis with hypersensitivity to sensory nerve C-fibers is the pathophysiology of atopic cough. Gefapixant is a first-in-class P2X 3 antagonist that has recently become available for clinical use in patients with refractory coughs. A 64-year-old female non-smoker presented to our hospital with a complaint of chronic intractable cough due to atopic cough. Addition of gefapixant (90 mg/day) to her previous treatment improved her distressing cough, despite the partial efficacy of many other drugs. The findings of this case demonstrate that P2X 3 inhibition is a viable therapeutic option for patients with chronic refractory cough caused by atopic cough. This case report offers valuable information regarding currently available treatment options for refractory chronic refractory cough caused by atopic cough. There remains an urgent need to clarify the disease entities presenting with chronic cough that can be effectively treated by inhibiting P2X 3 . Plain Language Summary: There is an urgent need to investigate more potent antitussive treatments for chronic refractory cough, because cough has a considerable impact on patients’ lives. Previous studies have shown that eosinophilic tracheobronchitis with hypersensitivity of sensory nerve C-fibers is the pathophysiology of atopic cough, which is a major cause of chronic cough in Japan. Gefapixant is a first-in-class P2X 3 antagonist that has recently become available for clinical use in patients with refractory coughs. Herein, we present the case of a 64-year-old female with a refractory atopic cough. The gefapixant add-on improved her distressing cough, indicating that P2X 3 inhibition could be a viable therapeutic option for patients with chronic refractory cough caused by atopic cough. Keywords: chronic cough, atopic cough, gefapixant, P2X 3