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Thorazine Side Effects

Generic Name: chlorpromazine

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

For the Consumer

Applies to chlorpromazine: oral tablets, parenteral injection

Side effects include:

Extrapyramidal reactions (e.g., Parkinson-like symptoms, dystonia, akathisia, tardive dyskinesia), drowsiness, dizziness, skin reactions or rash, dry mouth, orthostatic hypotension, amenorrhea, galactorrhea, weight gain.

For Healthcare Professionals

Applies to chlorpromazine: compounding powder, injectable solution, oral capsule extended release, oral concentrate, oral syrup, oral tablet, rectal suppository


The most frequently reported side effects included drowsiness, sedation, dry mouth, and nasal stuffiness.[Ref]


Very common (10% or more): Mild leukopenia (up to 30%)
Common (1% to 10%): Agranulocytosis, leukopenia, eosinophilia, hemolytic anemia, aplastic anemia, thrombocytopenia purpura, pancytopenia
Uncommon (0.1% to 1%): Purpura, leukocytosis, coagulation defects[Ref]

Nervous system

Acute dystonia and/or dyskinesia typically were transitory, occurring more frequently in children and young adults within the first 4 days of treatment or after dose changes.

Akathisia usually occurred after patients were given large initial doses.

Autonomic dysfunction occurred as a symptom of neuroleptic malignant syndrome.

Convulsive seizures have occurred more frequently in patients with a history of seizures and/or with EEG abnormalities.

Momentary fainting occurred most commonly in patients after the first injection, with a lower frequency of occurrence in subsequent injections; patients given oral formulations rarely fainted after the initial dose.

Parkinsonism more commonly occurred in adults and elderly patients after weeks to months of treatment.

Sedation and somnolence occurred more frequently at the start of treatment.[Ref]

Common (1% to 10%): Hypertonia, tardive dyskinesia, tardive dystonia, extrapyramidal syndrome, akathisia, parkinsonism, motor restlessness, drowsiness, convulsion/convulsive seizures (petit mal and grand mal), lowering of the seizure threshold, acute dyskinesia or dystonia
Uncommon (0.1% to 1%): Cerebral edema, epileptic fits, neuroleptic malignant syndrome, myasthenia gravis, abnormality of cerebrospinal fluid proteins
Frequency not reported: Lethargy, akinesia, hyperkinesia, autonomic dysfunction, tremor, drooling, pill rolling motion, cogwheel rigidity, shuffling gait, rhythmical involuntary movements of the tongue/face/mouth/jaw, involuntary movements of the extremities, fine vermicular movements of the tongue, dizziness, headache, momentary fainting, pseudo-parkinsonism, mask-like facies
Postmarketing reports: Cerebrovascular adverse events[Ref]


Common (1% to 10%): Dry mouth, constipation, nausea, obstipation, adynamic ileus, atonic colon
Uncommon (0.1% to 1%): Paralytic ileus
Postmarketing reports: Ischemic colitis, intestinal perforation/fatal intestinal perforation, gastrointestinal (GI) necrosis/fatal GI necrosis, intestinal obstruction, tongue protrusion, difficulty swallowing, necrotizing colitis/fatal necrotizing colitis[Ref]


Common (1% to 10%): Anxiety, mental confusion, agitation, excitement, aggravation of schizophrenic symptoms
Uncommon (0.1% to 1%): Nightmares, dysphoria, catatonic excitement, mental dulling/slowing
Rare (0.01% to 0.1%): Psychotic symptoms, catatonic-like states
Frequency not reported: Insomnia, altered mood, altered consciousness[Ref]

Altered consciousness occurred as a symptom of neuroleptic malignant syndrome.[Ref]


Accommodation disorder was related to anticholinergic effects of this drug.

Eye deposits occurred in the anterior segment of the eye from drug accumulation; however, the deposits usually did not have impact on sight.[Ref]

Common (1% to 10%): Blurred vision, photophobia, corneal/eye deposits, miosis and mydriasis
Uncommon (0.1% to 1%): Optic atrophy, lens opacities, pigmentary retinopathy, precipitation/aggravation of narrow angle glaucoma
Frequency not reported: Oculogyric crisis, ocular changes, accommodation disorder[Ref]


Lactation and breast engorgement in female patients occurred with large doses.

Urinary retention was linked to anticholinergic effects of this drug.[Ref]

Common (1% to 10%): Urinary retention/hesitancy, priapism, ejaculation disorders/impotence
Uncommon (0.1% to 1%): Amenorrhea, incontinence, lactation and moderate breast engorgement (female patients)
Frequency not reported: Galactorrhea, oligomenorrhea, erectile dysfunction, female sexual arousal disorder[Ref]


Common (1% to 10%): Contact dermatitis, photosensitivity/photosensitivity reaction, urticarial/maculopapular/petechial or edematous reaction
Uncommon (0.1% to 1%): Skin pigmentation, exfoliative dermatitis, toxic epidermal necrolysis
Frequency not reported: Allergic dermatitis, skin rashes
Postmarketing reports: Angioneurotic edema[Ref]


Common (1% to 10%): Impaired glucose tolerance, hyperglycemia, weight gain
Uncommon (0.1% to 1%): Hypoglycemia, water retention
Postmarketing reports: Hypertriglyceridemia, hyponatremia, increased appetite[Ref]


Cardiac arrest may be related to dose as well as preexisting conditions (e.g., cardiac disease, old age, hypokalemia, concurrent tricyclic antidepressants).

Hypertensive crisis occurred after abrupt withdrawal of treatment.

Orthostatic hypotension occurred more frequently in elderly and/or volume depleted patients, and was more likely to occur with IM administration.

Sudden cardiac death may be related to causes of cardiac origin.[Ref]

Common (1% to 10%): Orthostatic/postural hypotension, ECG changes (electrocardiogram QT prolongation, ST depression, U-Wave and T-Wave changes)
Uncommon (0.1% to 1%): Arrhythmias, hypertensive crisis, AV block, ventricular tachycardia/tachycardia, QT prolongation and fibrillation, edema, labile blood pressure
Frequency not reported: Ventricular fibrillation, Torsade de pointes, cardiac arrest, sudden cardiac death, profound hypotension, peripheral edema, venous embolism, deep vein thrombosis, cardiac arrhythmias (including ventricular and atrial arrhythmias)[Ref]


Common (1% to 10%): Hypothalamic effects, hyperprolactinemia/elevated prolactin levels
Uncommon (0.1% to 1%): Gynecomastia, profuse sweating, false positive pregnancy tests, inappropriate antidiuretic hormone secretion[Ref]


Hyperthermia occurred as a symptom of neuroleptic malignant syndrome.

Mild fevers have occurred in patient who received large doses intramuscularly.

Sudden death may be related to causes of cardiac origin, asphyxia, convulsions, or hyperpyrexia.[Ref]

Common (1% to 10%): Paradoxical reactions, impaired thermoregulation/temperature regulation disorder
Uncommon (0.1% to 1%): Hyperthermia, hypothermia, malignant hyperpyrexia
Frequency not reported: Sudden death, jitteriness, neonatal drug withdrawal syndrome[Ref]


Common (1% to 10%): Nasal congestion/stuffiness, respiratory depression
Uncommon (0.1% to 1%): Dyspnea
Frequency not reported: Bronchospasm, pulmonary embolism/fatal pulmonary embolism
Postmarketing reports: Asthma, laryngeal edema, throat tightness, asphyxia (failure of the cough reflex)[Ref]


Contact sensitization has occurred in individuals who frequently handled this drug.[Ref]

Common (1% to 10%): Injection site pain, injection abscess
Uncommon (0.1% to 1%): Contact skin sensitization[Ref]


Common (1% to 10%): Positive systemic lupus erythematosus (SLE) cells, antinuclear antibody (ANA) positive/raised ANA titer[Ref]


Common (1% to 10%): Cholestatic jaundice
Uncommon (0.1% to 1%): Liver injury, fatal liver injury, cholestatic/hepatocellular or mixed liver injury
Frequency not reported: Progressive hepatic fibrosis[Ref]


Uncommon (0.1% to 1%): Elevated creatine phosphokinase, muscular rigidity/rigidity, myoglobinuria/rhabdomyolysis
Rare (0.01% to 0.1%): Systemic lupus erythematosus
Frequency not reported: Torticollis, trismus
Postmarketing reports: Prolonged, abnormal muscle contractions, neck muscle spasms[Ref]

Elevated creatine phosphokinase, muscular rigidity, and myoglobinuria/rhabdomyolysis are symptoms of neuroleptic malignant syndrome.

Rigidity occurred as a symptom of neuroleptic malignant syndrome.[Ref]


Uncommon (0.1% to 1%): Glycosuria, acute renal failure[Ref]


Uncommon (0.1% to 1%): Severe allergic reactions/allergic reactions
Rare (0.01% to 0.1%): Anaphylactic/anaphylactoid reactions
Frequency not reported: Angioedema[Ref]


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

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

3. "Product Information. Thorazine (chlorpromazine)." SmithKline Beecham, Philadelphia, PA.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.