Phenergan

Meaning of Phenergan: Phenergan is the brand name for promethazine, an antihistamine also used to control nausea, vomiting, and to promote sedation.

Definition of Phenergan

Phenergan is a brand name for promethazine, a first generation antihistamine that blocks the action of histamine at H1 receptors. Because it also has sedating and anticholinergic properties, it is used for several purposes beyond allergy symptoms, including preventing and treating nausea and vomiting, easing motion sickness, and providing sedation before or after a procedure.

Promethazine belongs to the phenothiazine chemical class, a group of compounds that also includes certain antipsychotic medications, though promethazine itself is used for its antihistamine and antiemetic effects rather than to treat psychiatric conditions. It can be given by mouth, injection, or rectal suppository depending on the situation.

Because promethazine causes significant drowsiness, this sedating effect is sometimes the reason it is chosen, such as for sedation or nausea control, while at other times it is simply an expected side effect of using the medication to treat allergy symptoms.