Acetaminophen/Diphenhydramine

**Semantic type:** Pharmacologic Substance

**Definition:** A synthetic p-aminophenol derivative and diphenhydramine combination with anti-inflammatory, analgesic, and anti-allergic properties. Acetaminophen Diphenhydramine is used to treat symptoms of allergies and hay fever. The active principal metabolite of phenacetin, acetaminophen appears to inhibit prostaglandin biosynthesis in the central nervous system and less in peripheral tissues. Diphenhydramine blocks histamine effects, preventing sneezing and itchy, watery eyes, as well as nasal and other allergy and hay fever symptoms. (NCI04)