Promethazine, one of a group called Phenothiazines, is used to treat serious mental and emotional disorders, including schizophrenia and other psychotic disorders. Some are used also to control agitation in certain patients, severe nausea and vomiting, severe hiccups, and moderate to severe pain in some hospitalized patients.
Be sure to tell your doctor of any allergies you have whether it is to medication or food, preservatives, or dyes. Tell your doctor immediately if you are, or become pregnant, or are breastfeeding, as it is unknown how Promethazine may affect your baby. Also, tell your doctor of any other medications you are taking, including vitamins and supplements, and any medical conditions you may have.
Avoid alcohol when taking this medicine.
It is very important that you take this medicine exactly as your doctor tells you to. Do not take more or less medicine than directed, and never stop taking Promethazine without discussing it with your doctor first.
If you miss a dose of this medicine, take it as soon as you remember, unless it is almost time for your next dose. Do NOT double doses.
Stop taking this medicine and tell your doctor immediately if any of the following side effects occur: confusion or coma; difficult or fast breathing; drooling; fast heartbeat; fever; high or low blood pressure; increased sweating; loss of bladder control; muscle stiffness; trembling or shaking; trouble in speaking or swallowing.
Promethazine hydrochloride is a racemic compound; the empirical formula is C17H20N2S.HCl and its molecular weight is 320.88. Promethazine hydrochloride occurs as a white to faint yellow, practically odorless, crystalline powder which slowly oxidizes and turns blue on prolonged exposure to air. It is soluble in water and freely soluble in alcohol.
Injection: Each ml of the Tubex and Tubex Blunt Pointe Sterile Cartridge Units contains either 25 or 50 mg promethazine hydrochloride with 0.1 mg edetate disodium, 0.04 mg calcium chloride, not more than 5 mg monothioglycerol and 5 mg phenol with sodium acetate-acetic acid buffer. Sealed under nitrogen. Tablets and Suppositories: Each tablet of Phenergan contains 12.5 mg, 25 mg, or 50 mg promethazine hydrochloride. The inactive ingredients present are lactose, magnesium stearate, and methylcellulose. Each dosage strength also contains the following: 12.5 mg¾FD&C Yellow 6 and saccharin sodium; 25 mg¾saccharin sodium; 50 mg¾FD&C Red 40.
Syrup: Each teaspoon (5 ml) of Phenergan Syrup Plain contains 6.25 mg promethazine hydrochloride in a flavored syrup base with a pH between 4.7 and 5.2. Alcohol 7%. The inactive ingredients present are artificial and natural flavors, citric acid, D&C Red 33, D&C Yellow 10, FD&C Blue 1, FD&C Yellow 6, glycerin, saccharin sodium, sodium benzoate, sodium citrate, sodium propionate, water, and other ingredients.
Promethazine has the following structural formula: