Nurses Compass
Drug Guide
Chlorprothixene
Classification
Therapeutic: Antipsychotic, typical
Pharmacological: Thioxanthene derivative
FDA Approved Indications
- Schizophrenia
- Manic-depressive illness, related psychoses
Mechanism of Action
Chlorprothixene acts by blocking dopamine D2 receptors in the brain, which helps to alleviate psychotic symptoms. It may also have antihistaminic, anticholinergic, and alpha-adrenergic blocking properties.
Dosage and Administration
Adult: Typically 25-50 mg 3-4 times daily, adjustable based on response and tolerability.
Pediatric: Use is not well established; dosage should be determined by a pediatric psychiatrist.
Geriatric: Lower starting doses are recommended due to increased sensitivity and risk of side effects.
Renal Impairment: Adjust doses cautiously; no specific guidelines, monitor closely.
Hepatic Impairment: Use with caution; dose adjustments may be necessary, monitor liver function.
Pharmacokinetics
Absorption: Well absorbed from the gastrointestinal tract.
Distribution: Widely distributed; crosses the blood-brain barrier.
Metabolism: Metabolized extensively in the liver.
Excretion: Primarily excreted in urine and feces.
Half Life: Approximately 4-8 hours.
Contraindications
- Hypersensitivity to chlorprothixene or other thioxanthene derivatives.
- Coma or CNS depression.
Precautions
- Use with caution in elderly patients, patients with cardiovascular disease, and in those with a history of seizures.
- Pregnancy category C; can be used if the potential benefit justifies risks.
- Lactation: Consider benefits vs. risks; may pass into breast milk.
Adverse Reactions - Common
- Drowsiness, sedation (Frequent)
- Dry mouth (Frequent)
- Blurred vision (Occasional)
- Constipation (Occasional)
Adverse Reactions - Serious
- Extrapyramidal symptoms (Uncommon)
- Agranulocytosis (Rare)
- QT prolongation / cardiac arrhythmias (Rare)
- Neuroleptic malignant syndrome (Rare)
Drug-Drug Interactions
- CNS depressants (enhances sedation)
- Other antipsychotics (risk of increased side effects)
- CNS-stimulants (may counteract sedative effects)
Drug-Food Interactions
- Alcohol (enhanced sedative effects)
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor mental status, neurological status, and for extrapyramidal symptoms. Check baseline ECG if needed.
Diagnoses:
- Risk for falls due to sedation or orthostatic hypotension
- Impaired physical mobility related to extrapyramidal symptoms
Implementation: Administer with food to decrease GI upset. Educate about side effects and safety precautions.
Evaluation: Assess effectiveness in symptom control and monitor for adverse effects.
Patient/Family Teaching
- Do not operate heavy machinery until you know how the drug affects you.
- Avoid alcohol and other CNS depressants.
- Report any signs of unusual movements, fever, or muscle rigidity.
- Take medication exactly as prescribed.
Special Considerations
Black Box Warnings:
- Increased mortality in elderly patients with dementia-related psychosis; avoid use in this population
Genetic Factors: CYP2D6 poor metabolizers may have increased plasma levels.
Lab Test Interference: May cause false-positive urinary catecholamine screening.
Overdose Management
Signs/Symptoms: Drowsiness, agitation, hallucinations, seizures, extravasation, coma, hypotension, QT prolongation.
Treatment: Supportive care, gastric lavage, activated charcoal if recent ingestion, cardiac monitoring. Specific antidote not available.
Storage and Handling
Storage: Store at room temperature, away from light and moisture.
Stability: Stable under normal storage conditions for shelf life specified by manufacturer.