What is Promethazine?
Promethazine hydrochloride (Phenergan®) is a prescription medication used for a variety of different uses. It is most commonly used for treating nausea and vomiting, but is frequently used for other purposes too.
As a sedating antihistamine, promethazine belongs to a group of drugs known as phenothiazines. It has several different effects in the body and the brain. Many of these effects are likely due to its antihistamine activity, since promethazine also works by blocking histamine receptors.
In addition, the medication blocks acetylcholine receptors, which is probably why it helps to alleviate nausea and motion sickness.
Promethazine comes in several different forms. It can be taken orally (tablets and syrup), inserted rectally (rectal suppositories), or administered by injection at a hospital. The medication is usually taken one to three times daily, although dosing instructions will vary, depending on the specific condition being treated.
(Click Promethazine for more information on what this medicine is used for, potential side effects, and what you should discuss with your healthcare provider before starting treatment.)