Skip to Content

Phenergan Side Effects

Generic Name: promethazine

Note: This document contains side effect information about promethazine. Some of the dosage forms listed on this page may not apply to the brand name Phenergan.

For the Consumer

Applies to promethazine: solution

Along with its needed effects, promethazine (the active ingredient contained in Phenergan) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking promethazine:

Rare
  • Convulsions (seizures)
  • difficult or unusually fast breathing
  • fast heartbeat or irregular pulse
  • high fever
  • high or low blood pressure
  • increased sweating
  • loss of bladder control
  • severe muscle stiffness
  • unusually pale skin
  • unusual tiredness or weakness
Incidence not known
  • Abdominal or stomach pain
  • black, tarry stools
  • blood in the urine
  • bloody nose
  • blurred vision
  • chest pain or discomfort
  • chills
  • clay-colored stools
  • cough or hoarseness
  • dark urine
  • decreased awareness or responsiveness
  • difficulty with speaking
  • dizziness
  • double vision
  • drooling
  • fast, pounding, or irregular heartbeat or pulse
  • fever with or without chills
  • fixed position of the eye
  • headache
  • heavier menstrual periods
  • increases and decreases in blood pressure
  • itching
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • lightheadedness, dizziness, or fainting
  • loss of appetite
  • loss of balance control
  • lower back or side pain
  • mimicry of speech or movements
  • muscle trembling, jerking, or stiffness
  • mutism
  • nausea
  • negativism
  • noisy breathing
  • painful or difficult urination
  • peculiar postures or movements, mannerisms, or grimacing
  • pinpoint red spots on the skin
  • restlessness
  • seeing double
  • seeing, hearing, or feeling things that are not there
  • seizures
  • severe sleepiness
  • shortness of breath
  • shuffling walk
  • skin rash
  • slow or irregular heartbeat
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stiffness of the limbs
  • swollen glands
  • tenderness, pain, swelling, warmth, skin discoloration, and prominent superficial veins over the affected area
  • tightness in the chest
  • tremors
  • twisting movements of the body
  • uncontrolled movements, especially of the face, neck, and back
  • unpleasant breath odor
  • unusual bleeding or bruising
  • vomiting of blood
  • wheezing
  • yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking promethazine:

Symptom of overdose
  • Abnormal movements
  • confusion as to time, place, or person
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • feeling of warmth
  • holding false beliefs that cannot be changed by fact
  • hyperexcitability
  • irregular, fast or slow, or shallow breathing
  • nightmares
  • pale or blue lips, fingernails, or skin
  • pupils of the eyes, large and not moving or responding to light
  • redness of the face, neck, arms, and occasionally, upper chest
  • sweating
  • troubled breathing
  • unusual excitement, nervousness, or restlessness

Some side effects of promethazine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known
  • Blistering, crusting, irritation, or reddening of the skin
  • continuing ringing or buzzing or other unexplained noise in the ears
  • discoloration of the skin
  • drowsiness
  • dry mouth
  • excitation
  • false or unusual sense of well-being
  • hearing loss
  • hives or welts
  • increased sensitivity of the skin to sunlight
  • lack of coordination
  • loss of strength or energy
  • muscle pain or weakness
  • nasal stuffiness
  • nervousness
  • severe sunburn
  • sleeplessness
  • trouble sleeping
  • unable to sleep
  • vomiting

For Healthcare Professionals

Applies to promethazine: compounding powder, injectable solution, oral syrup, oral tablet, rectal suppository

General

The most commonly reported side effect include drowsiness, dizziness, and restlessness.[Ref]

Nervous system

Frequency not reported: Drowsiness, sedation, somnolence, dizziness, extrapyramidal symptoms, incoordination, tremors, convulsive seizures, faintness, headache, neuroleptic malignant syndrome/fatal neuroleptic malignant syndrome, psychomotor impairment, antimuscarinic effects, abnormal movements, central nervous system depression, activation of epileptogenic foci, tardive dyskinesia, tic-like movements of the head and face[Ref]

Local

Frequency not reported: Severe chemical irritation, tissue damage, burning, pain, erythema, swelling, sensory loss, palsies, paralysis, severe spasm of distal vessels, thrombophlebitis, venous thrombosis, phlebitis, abscesses, tissue necrosis, gangrene[Ref]

Psychiatric

Frequency not reported: Restlessness, anxiety, confusion, disorientation, euphoria, nervousness, insomnia, catatonic-like states, irritability, hysteria, hallucinations, hyperexcitability, nightmares, delirium, agitation/agitated behavior[Ref]

Gastrointestinal

Frequency not reported: Dry mouth, nausea, vomiting, constipation, diarrhea, tongue protrusion, gastric irritation, epigastric distress[Ref]

Cardiovascular

Frequency not reported: Bradycardia, tachycardia, palpitations, hypotension, arrhythmias, circulatory collapse, increased or decreased blood pressure[Ref]

Hematologic

Frequency not reported: Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis, blood dyscrasias, hemolytic anemia, aplastic anemia[Ref]

Dermatologic

Frequency not reported: Dermatitis, photosensitivity, urticaria, rash, pruritus, angioneurotic edema, topical contact dermatitis[Ref]

Other

Frequency not reported: Lassitude, tinnitus, fatigue, tiredness, paradoxical reactions, decreased performance (impaired driving/poor work performance, incoordination, reduced motor skills, impaired information processing)[Ref]

Respiratory

Frequency not reported: Asthma, nasal stuffiness, respiratory depression/fatal respiratory depression, apnea/fatal apnea, marked irregular respiration[Ref]

Ocular

Frequency not reported: Blurred vision, oculogyric crisis, diplopia, angle closure glaucoma[Ref]

Hypersensitivity

Frequency not reported: Anaphylaxis, angioedema, hypersensitivity reactions[Ref]

Musculoskeletal

Frequency not reported: Torticollis, muscle spasms, muscle dyskinesia[Ref]

Metabolic

Frequency not reported: Anorexia, loss of appetite, appetite stimulation[Ref]

Hepatic

Frequency not reported: Jaundice, obstructive jaundice[Ref]

Genitourinary

Frequency not reported: Urinary retention and hesitancy[Ref]

References

1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. "Product Information. Phenergan (promethazine)." Wyeth-Ayerst Laboratories, Philadelphia, PA.

4. "Product Information. Promethazine Hydrochloride (promethazine)." ESI Lederle Generics, Philadelphia, PA.

Some side effects of Phenergan may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.

Hide