Diphenhydramine

Drug class: Antihistamine

• An antihistamine that suppresses the urge to cough and also dries secretions in the nose and chest.
• Causes drowsiness which is helpful if the cough disturbs sleep.

Ammonium Chloride 

Drug class: Electrolyte

• Increases respiratory secretions with less tenacious sputum which is easier to expectorate

Sodium Citrate

Drug class: Urinary alkalinizer

• A mucolytic agent that breaks down mucus so that coughing up phlegm is easier.

Menthol

Drug class: Counterirritant

• Useful in throat irritation, sore throat or incisal congestion and gives cooling effect to the nasal passage.
• Reduces irritation of pharynx and soothes throat.