Promethazine is in a group of drugs called phenothiazines (FEEN-oh-THYE-a-zeens). It works by changing the actions of chemicals in your brain. Promethazine also acts as an antihistamine. It blocks the effects of the naturally occurring chemical histamine in your body.
Promethazine is not for use in treating symptoms of asthma, pneumonia, or other lower respiratory tract infections.
How should I take promethazine?
Take promethazine exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Promethazine is often taken at bedtime or before meals. For motion sickness, promethazine is usually started within 1 hour before traveling. When used for surgery, promethazine is usually taken the night before the surgery.
How often you take this medicine and the timing of your dose will depend on the condition being treated.
Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
If a child is using this medicine, tell your doctor if the child has any changes in weight. Promethazine doses are based on weight in children, and any changes may affect your child’s dose.
This medicine can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using promethazine.