Promethazine is in a group of drugs called phenothiazines (feen-oh-THYE-oh-zeens).

Promethazine is used to treat or prevent nausea and vomiting caused by anesthesia or surgery, certain types of allergic reactions, pain caused by surgery or childbirth, and to sedate patients before surgery or medical procedures.

Promethazine injection is usually given when a person cannot take the medication orally (by mouth).

Promethazine injection may also be used for purposes not listed in this medication guide.

Stop using this medication and call your doctor at once if you have twitching or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs. These could be early signs of dangerous side effects.

You should not receive this medication if you are allergic to promethazine or to similar medicines such as chlorpromazine (Thorazine), fluphenazine (Prolixin), mesoridazine (Serentil), perphenazine (Trilafon), prochlorperazine (Compazine), thioridazine (Mellaril), or trifluperazine (Stelazine).

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Tell your doctor right away if you have serious side effects while receiving promethazine injection, such as slow, shallow breathing, feeling light-headed, fainting, severe burning or skin irritation where the injection was given, confusion, hallucinations, muscle twitching, or muscle movements you cannot control.

You should not use this medication if you are allergic to promethazine or to similar medicines such as chlorpromazine (Thorazine), fluphenazine (Prolixin), mesoridazine (Serentil), perphenazine (Trilafon), prochlorperazine (Compazine), thioridazine (Mellaril), or trifluperazine (Stelazine).

To make sure you can safely use promethazine, tell your doctor if you have any of these other conditions:

• asthma, sleep apnea, or other breathing problems;

• epilepsy or other seizure disorder;

• a weak immune system (bone marrow depression);

• glaucoma;

• enlarged prostate or problems with urination;

• stomach ulcer or obstruction;

• heart disease or high blood pressure;

• liver disease;

• adrenal gland tumor (pheochromocytoma);

• low levels of calcium in your blood (hypocalcemia); or

• if you have ever had a serious side effect while using promethazine or any other phenothiazine.

FDA pregnancy category C. It is not known whether promethazine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

It is not known whether promethazine passes into breast milk or if it could harm a nursing baby. Do not receive this medication without telling your doctor if you are breast-feeding a baby.