This preparation is a combination of an antitussive, decongestant, and antihistamine agent. Dextromethorphan is a safe, effective, non-narcotic antitussive that acts centrally on the cough center in the medulla. Although structurally related to morphine, it has no analgesic or habit-forming properties and generally has little sedative effect. Phenylephrine is a decongestant that constricts blood vessels in the nasal passages. It is used for temporary relief of nasal, sinus, and ear congestion caused by the common cold, flu, allergies, sinusitis, and bronchitis. It reduces swelling in the nose and ears, thereby improving breathing and relieving discomfort. Triprolidine is an antihistamine used to relieve symptoms of allergy, hay fever, and the common cold, including rash, watery eyes, itchy eyes/nose/throat/skin, cough, runny nose, and sneezing. It is a potent competitive H1-receptor antagonist of the pyrrolidine class with mild central nervous system depressant effects that may cause drowsiness. It also helps reduce body fluid secretions by antagonizing acetylcholine, thereby relieving symptoms such as watery eyes and runny nose.