Promethazine

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Aug 04, 2022

Side Effects


Promethazine Side Effects

Common side effects of promethazine are listed below. Tell your doctor if they are severe or do not go away in a few days.

  • Drowsiness
  • Dizziness
  • Dry mouth
  • Blurry vision
  • Ringing in the ears
  • Confusion
  • Lethargy
  • Sleep difficulties
  • Nightmares
  • Loss of coordination
  • Nervousness, hyperactivity, restlessness
  • Nausea, vomiting
  • Itching
  • Stuffy nose

Some of the side effects of promethazine are more serious. Contact your healthcare provider right away or seek emergency medical attention if you experience any of the following side effects:

  • Slowed breathing, stopped breathing, or difficulty breathing
  • Fever, sweating, stiff muscles
  • Irregular heartbeat
  • Fainting
  • Decreased alertness
  • Uncontrollable movements
  • Hallucinations
  • Extreme fear or strong emotions
  • Confusion
  • Seizures
  • Sore throat, fever, chills, or other signs of infection
  • Abnormal eye movements, abnormal neck position, or tongue thrusting
  • Rash, hives, itching

The above list may not include all the potential side effects of promethazine. Talk to your doctor if you have any unusual side effects or if your side effects do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Promethazine Overdose: In case of a known or suspected overdose of promethazine, contact your doctor immediately or call the poison control center at 1-800-222-1222. If a person has collapsed, cannot breathe, or has had a seizure, call 911. Symptoms of a promethazine overdose may include wheezing, difficulty breathing, slowed or stopped breathing, dizziness, loss of consciousness, fast heartbeat, stiff muscles, uncontrolled movements, dry mouth, flushing, wide pupils, agitation or abnormal excitement, nightmares, nausea, and constipation.

NOTE: Promethazine is a prescription medicine to be used only by you—never share your medicine with others or use someone else’s promethazine.

Source: FDA