Promethazine: Uses & Side effects

Promethazine is in a group of drugs called phenothiazines. 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 used to treat allergy symptoms such as itching, runny nose, sneezing, itchy or watery eyes, hives, and itchy skin rashes. It also prevents motion sickness, and treats nausea and vomiting or pain after surgery. It is also used as a sedative or sleep aid.

Important information

Stop using promethazine 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. Promethazine should not be given to a child younger than 2 years old. Promethazine can cause severe breathing problems or death in a child in very young children. Carefully follow your doctor’s instructions when giving this medicine to a child of any age.

Promethazine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Avoid drinking alcohol, which can increase some of the side effects of promethazine. There are many other medicines that can interact with promethazine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you.

Side effects

Get emergency medical help if you have any signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using promethazine and call your doctor at once if you have:

  • severe drowsiness, weak or shallow breathing;
  • a light-headed feeling, like you might pass out;
  • confusion, agitation, hallucinations, nightmares;
  • seizure (convulsions);
  • fast or slow heartbeats;
  • jaundice (yellowing of the skin or eyes);
  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
  • easy bruising or bleeding (nosebleeds, bleeding gums);
  • sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, red or swollen gums, trouble swallowing; or
  • severe nervous system reaction–very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

Side effects such as confusion and severe drowsiness may be more likely in older adults.

Common promethazine side effects may include:

  • drowsiness, dizziness;
  • ringing in your ears;
  • double vision;
  • feeling nervous;
  • dry mouth; or
  • tired feeling, sleep problems (insomnia).


Keywords: Promethazine

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.