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 Phenadoz.
Applies to promethazine: oral syrup, oral tablet
Other dosage forms:
Oral route (Tablet; Syrup)
Promethazine hydrochloride should not be used in pediatric patients less than 2 years old because of the potential for fatal respiratory depression. Exercise caution when administering to pediatric patients 2 years or older and use at the lowest effective dose. Avoid concomitant use of other drugs with respiratory depressant effects.
Along with its needed effects, promethazine (the active ingredient contained in Phenadoz) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Stop taking promethazine and get emergency help immediately if any of the following effects occur:
Rare- Symptoms of neuroleptic malignant syndrome; two or more occur together; most of these effects do not require emergency medical attention if they occur alone
Check with your doctor immediately if any of the following side effects occur while taking promethazine:
Incidence not known
Symptoms of overdose
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
Applies to promethazine: compounding powder, injectable solution, oral syrup, oral tablet, rectal suppository
The most commonly reported side effect include drowsiness, dizziness, and restlessness.
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
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
Frequency not reported: Restlessness, anxiety, confusion, disorientation, euphoria, nervousness, insomnia, catatonic-like states, irritability, hysteria, hallucinations, hyperexcitability, nightmares, delirium, agitation/agitated behavior
Frequency not reported: Dry mouth, nausea, vomiting, constipation, diarrhea, tongue protrusion, gastric irritation, epigastric distress
Frequency not reported: Bradycardia, tachycardia, palpitations, hypotension, arrhythmias, circulatory collapse, increased or decreased blood pressure
Frequency not reported: Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis, blood dyscrasias, hemolytic anemia, aplastic anemia
Frequency not reported: Dermatitis, photosensitivity, urticaria, rash, pruritus, angioneurotic edema, topical contact dermatitis
Frequency not reported: Lassitude, tinnitus, fatigue, tiredness, paradoxical reactions, decreased performance (impaired driving/poor work performance, incoordination, reduced motor skills, impaired information processing)
Frequency not reported: Asthma, nasal stuffiness, respiratory depression/fatal respiratory depression, apnea/fatal apnea, marked irregular respiration
Frequency not reported: Blurred vision, oculogyric crisis, diplopia, angle closure glaucoma
Frequency not reported: Anaphylaxis, angioedema, hypersensitivity reactions
Frequency not reported: Torticollis, muscle spasms, muscle dyskinesia
Frequency not reported: Anorexia, loss of appetite, appetite stimulation
Frequency not reported: Jaundice, obstructive jaundice
Frequency not reported: Urinary retention and hesitancy
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Phenadoz