COSTUS – DX SYRUP with powerful formulation of Dextromethorphan hydrobromide 10mg + chlorpheniramine maleate 4mg is acts as a cough suppressant by reducing the cough reflex, providing relief from persistent non-productive cough, while Chlorpheniramine Maleate is an antihistamine that helps relieve allergy symptoms such as sneezing, runny nose, watery eyes, and throat irritation.