Nurses Compass
Drug Guide
Thiothixene
Classification
Therapeutic: Antipsychotic, typical
Pharmacological: Thioxanthene derivative, dopamine D2 receptor antagonist
FDA Approved Indications
- Schizophrenia
Mechanism of Action
Thiothixene primarily acts by blocking dopamine D2 receptors in the brain, which helps to reduce psychotic symptoms such as hallucinations and delusions.
Dosage and Administration
Adult: 10-30 mg daily in divided doses, adjusted based on response and tolerability
Pediatric: Not typically recommended for pediatric use
Geriatric: Start at lower doses due to increased sensitivity; monitor closely
Renal Impairment: Use caution; no specific adjustment recommended but monitor closely
Hepatic Impairment: Use caution; dose adjustments may be necessary based on liver function
Pharmacokinetics
Absorption: Well absorbed orally
Distribution: Widely distributed in body tissues, crosses the blood-brain barrier
Metabolism: Primarily metabolized in the liver via CYP450 enzymes
Excretion: Excreted mainly in urine and feces
Half Life: Approximately 4-6 hours; active metabolites may have longer half-lives
Contraindications
- Coma or severe CNS depression
- Use of large amounts of CNS depressants
- Parkinson’s disease
Precautions
- History of QT prolongation, arrhythmias, or electrolyte imbalances; caution in elderly due to risk of falls and confusion; careful monitoring of blood counts and metabolic parameters
Adverse Reactions - Common
- Drowsiness/Sedation (Common)
- Extrapyramidal symptoms (EPS) (Common)
- Dry mouth (Common)
- Weight gain (Common)
Adverse Reactions - Serious
- QT prolongation and risk of torsades de pointes (Serious, dose-related)
- Neuroleptic Malignant Syndrome (NMS) (Rare but serious)
- Agranulocytosis (Rare)
- Tardive dyskinesia (Less common with long-term use)
Drug-Drug Interactions
- Other CNS depressants, levodopa, anticoagulants, drugs that prolong QT interval
Drug-Food Interactions
- Alcohol, caffeine, grapefruit juice (may affect metabolism)
Drug-Herb Interactions
- St. John’s Wort, Ginseng (may interact with CNS drugs)
Nursing Implications
Assessment: Monitor for signs of neuroleptic side effects, cardiovascular status, and metabolic changes. Baseline ECG recommended in patients at risk.
Diagnoses:
- Risk for injury related to extrapyramidal symptoms or sedation
- Impaired glucose tolerance or risk for diabetes
Implementation: Administer with food if GI upset occurs; monitor EPS regularly; educate patient about symptoms of NMS and tardive dyskinesia.
Evaluation: Assess effectiveness in reducing psychotic symptoms; monitor for adverse effects; adjust dosage as needed.
Patient/Family Teaching
- Do not discontinue abruptly to avoid withdrawal symptoms.
- Report signs of movement disorders, fever, or muscle rigidity immediately.
- Be aware of potential drowsiness; avoid driving or operating machinery until response is known.
- Avoid alcohol and other CNS depressants.
Special Considerations
Black Box Warnings:
- Increased mortality in elderly patients with dementia-related psychosis.
Genetic Factors: Genetic variability may influence metabolism and response.
Lab Test Interference: May cause elevations in liver enzymes, blood glucose, and lipid levels.
Overdose Management
Signs/Symptoms: Extrapyramidal symptoms, hypotension, sedation, seizures, coma
Treatment: Supportive care; activated charcoal if ingestion recent; cardiovascular monitoring; consider use of benzodiazepines for agitation; physostigmine may be considered for anticholinergic toxicity under specialist guidance.
Storage and Handling
Storage: Store at room temperature, protected from light and moisture
Stability: Stable for 2-3 years if stored properly