What is Promethazine? Uses, warnings & side effects

Use this medicine as directed.

Promethazine tablets, oral solution, and syrup can be taken without regard to food.

• If the doses cause stomach problems, take doses with milk or food.

Swallow tablets whole with a glass of water.

Measure the oral liquid medicine with a calibrated oral syringe provided by the pharmacist.

When using suppositories, please follow the prescriber’s instructions on how to administer a dose.

• Suppositories are only to be used in the rectum. Do not take them by mouth.

Store promethazine tablets and liquid at room temperature protected from light. Do not freeze the oral liquid.

Store promethazine suppositories in the refrigerator.

Ask the prescriber how to handle a missed dose.

Whether missed doses are taken or skipped depends on the condition being treated and the dosing schedule.

Do not take extra medicine to make up for a missed dose.

This medicine is not right for everyone. 

Promethazine is contraindicated in anyone who:

• Has had an allergic or any other type of reaction to promethazine or another phenothiazine medicine

• Is in a coma

• Is younger than 2 years of age

Promethazine should never be used for asthma or lower respiratory tract symptoms.

Tell any doctor or other healthcare provider who treats you that you are taking promethazine.

• Promethazine can interfere with important lab tests, including pregnancy tests.

Keep all appointments with the prescriber when taking this medicine.

Before taking promethazine, tell the prescriber if you are pregnant, breastfeeding, or have:

• Lung or breathing problems, including COPD, asthma, or sleep apnea

• Heart problems

• Glaucoma

• Stomach ulcer

• Bowel problems

• Enlarged prostate

• Trouble urinating

• Bone marrow suppression

• A seizure disorder

• Liver problems

• Parkinson disease

This medicine can cause serious side effects, including:

• Breathing problems, which could be life-threatening

• Neuroleptic malignant syndrome (a nervous system disorder that can be life-threatening)

• Increased risk of seizures

• Involuntary movements

This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Avoid sunlamps and tanning beds.

To avoid possible drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medicines, and supplements you are using before taking this drug, particularly:

• Other antihistamines

• Antipsychotics, particularly phenothiazine antipsychotics

• Drugs that make you sleepy, including sleeping pills, benzodiazepines, opioids, barbiturates, antidepressants, and alcohol

• Monoamine oxidase inhibitors (MAOIs)

• Anesthetics, including local anesthetics

• Drugs called anticholinergic medications

Avoid drinking alcohol when taking this medication. 

Tell other healthcare professionals treating you