Nurses Compass
Drug Guide
Thiothixene Hydrochloride
Classification
Therapeutic: Antipsychotic, Typical
Pharmacological: Thioxanthene derivative, dopamine D2 receptor antagonist
FDA Approved Indications
- Schizophrenia
Mechanism of Action
Thiothixene hydrochloride blocks dopamine D2 receptors in the brain, reducing psychotic symptoms. It also exerts some anticholinergic, antihistaminic, and alpha-adrenergic blocking effects.
Dosage and Administration
Adult: Typical starting dose is 2-5 mg 2-3 times daily; doses may be titrated based on response and tolerance, up to 30-60 mg daily in divided doses.
Pediatric: Safety and efficacy in children have not been established.
Geriatric: Use with caution; start at lower doses due to increased sensitivity to side effects.
Renal Impairment: Adjust dosage as needed; no specific guidelines, monitor response and side effects.
Hepatic Impairment: Use with caution; hepatic metabolism may be impaired, necessitating lower doses.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed; crosses blood-brain barrier.
Metabolism: Extensively metabolized in the liver via CYP450 enzymes.
Excretion: Excreted mainly in urine and feces.
Half Life: Approximately 4-6 hours, but active metabolites may prolong effects.
Contraindications
- Coma or severe CNS depression
- Congenital or acquired QT prolongation
Precautions
- History of hypersensitivity to thiothixene or other phenothiazines, elderly patients with dementia-related psychosis, Parkinson's disease, electroconvulsive therapy, history of seizures, cardiovascular disease, liver impairment, following recent myocardial infarction. Use cautiously in pregnancy and lactation.
Adverse Reactions - Common
- Drowsiness, sedation (Common)
- Dry mouth (Common)
- Extrapyramidal symptoms (EPS) (Common)
- Weight gain (Common)
Adverse Reactions - Serious
- QT prolongation, Torsades de Pointes (Serious)
- Neuroleptic Malignant Syndrome (NMS) (Rare)
- Seizures (Uncommon)
- Agranulocytosis (Rare)
Drug-Drug Interactions
- Other CNS depressants, anticholinergic drugs, drugs prolonging QT interval, antihypertensives
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor mental status, baseline ECG, blood counts, and weight. Observe for extrapyramidal symptoms and signs of NMS.
Diagnoses:
- Risk of falls, ineffective coping, risk of NMS, impaired urinary elimination.
Implementation: Administer with food to decrease GI irritation; monitor for adverse effects; adjust dosage based on response.
Evaluation: Assess for therapeutic response and side effects; ensure patient adherence and safety.
Patient/Family Teaching
- Do not operate machinery until you know how this medication affects you.
- Attend regular follow-up appointments.
- Report signs of allergic reactions, movement disorders, or signs of serious side effects like fever, muscular rigidity.
- Avoid alcohol and CNS depressants.
Special Considerations
Black Box Warnings:
- Increased mortality in elderly patients with dementia-related psychosis treated with antipsychotics.
Genetic Factors: Potential variability in metabolism due to CYP450 polymorphisms.
Lab Test Interference: May cause false positives in certain psychiatric or drug screenings.
Overdose Management
Signs/Symptoms: Drowsiness, severe hypotension, respiratory depression, extrapyramidal symptoms, seizures, QT prolongation.
Treatment: Supportive care, activated charcoal if ingested recently, ECG monitoring, correction of electrolyte imbalances, and specific interventions for cardiac arrhythmias.
Storage and Handling
Storage: Store at room temperature, away from moisture and light.
Stability: Stable under recommended conditions; check expiration date regularly.