Theraflu

**Semantic type:** Pharmacologic Substance

**Definition:** Any of the commercial combination preparations, by Novartis, containing a combination of any of the following agents: the analgesic antipyretic acetaminophen, an antihistamine (chlorpheniramine maleate, diphenhydramine hydrochloride, doxylamine succinate or pheniramine maleate), the antitussive dextromethorphan maleate and/or a decongestant (phenylephrine hydrochloride or pseudoephedrine hydrochloride). Theraflu preparations are used to relieve symptoms of cold and flu. Acetaminophen exerts its actions by inhibiting prostaglandin synthesis. The antihistamines block the effects of histamine. Dextromethorphan exerts its activity by raising the threshold for coughing in the cough center. The decongestants are sympathomimetic agents that cause vasoconstriction mediated through alpha-adrenergic receptors. This reduces blood flow, decreases swelling and prevents nasal and sinus congestion.