Coughex

• Refractory chronic cough
• Unexplained chronic cough

Gefapixant is a selective antagonist of the P2X3 receptor. P2X3-containing receptors belong to the family of purinergic receptors and are ATP-dependent ion channels, which are also located on sensory C-fibers of the vagus nerve in the airways. C-fibers are activated in response to inflammation or chemical irritants. Under inflammatory conditions, ATP is released by mucosal cells of the respiratory tract. The binding of extracellular ATP to P2X3 receptors is recognized by C-fibers as a damage signal and is perceived as a coughing stimulus, which in turn triggers a cough reflex.

Adult Dose:

• One 45 mg tablet orally twice daily with or without food
• If a dose is missed, skip it and take the next dose at the regular time

Severe Renal Impairment (eGFR <30 mL/min/1.73m²):

• One 45 mg tablet once daily with or without food

Elderly: No dose adjustment required (higher risk of reduced renal function)

Children (under 18 years): Safety and efficacy not established

* Use as directed by the registered physician

Very Common (>10%):

• Dysgeusia (taste disturbance)
• Ageusia (loss of taste)
• Hypogeusia (reduced taste)

Common (1-10%):

• Upper respiratory tract infections
• Decreased appetite
• Dizziness
• Nausea
• Diarrhea
• Dry mouth
• Hypersalivation
• Epigastric pain
• Dyspepsia

Occasional: Urinary stones, bladder stones, nephrolithiasis

Use in Pregnancy: Use during pregnancy and in women of childbearing potential who do not use contraception is not recommended.

Precautions:

• Use with caution in patients with known hypersensitivity to sulphonamides.
• Should not be used in patients with obstructive sleep apnea.
• May affect driving ability and use of machines (dizziness) - caution required.

Overdose: Patient should be observed for adverse reactions and appropriate symptomatic treatment initiated. Gefapixant is partially removed by hemodialysis.

Storage: Store below 30°C in a cool and dry place. Keep away from light. Keep out of reach of children.