Home Drug Guide Thiethylperazine Malate

Drug Guide

Generic Name

Thiethylperazine Malate

Brand Names Torecan

Classification

Therapeutic: Antiemetic, Antipsychotic (Typical phenothiazine)

Pharmacological: Dopamine antagonist, Phenothiazine derivative

FDA Approved Indications

Prevention and treatment of nausea and vomiting

Mechanism of Action

Thiethylperazine blocks dopamine receptors in the central nervous system, which helps prevent nausea and vomiting. It may also have sedative and anti-allergic effects.

Dosage and Administration

Adult: 25-50 mg 3-4 times daily, orally or intramuscularly, based on clinical response.

Pediatric: Use is less common; dosage must be cautious and pediatrician-guided.

Geriatric: Start at lower end of dosing range due to increased sensitivity; monitor closely.

Renal Impairment: Adjust dose cautiously; no specific guidelines—monitor patient's response.

Hepatic Impairment: Use with caution, as metabolism may be impaired; no specific dosage adjustment established.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses the blood-brain barrier.

Metabolism: Hepatic, primarily via conjugation.

Excretion: Via urine and feces.

Half Life: Approximately 9-12 hours, variable depending on individual factors.

Contraindications

Hypersensitivity to phenothiazines
Comorbid Parkinson's disease
Bone marrow depression

Precautions

Use with caution in patients with cardiovascular disease, CNS depression, epilepsy, or liver impairment.
Pregnancy category C; use only if potential benefits justify risks.
Lactation: May pass into breast milk; risk vs. benefit should be considered.

Adverse Reactions - Common

Drowsiness or sedation (Common)
Dizziness (Common)
Dry mouth (Common)
Blurred vision (Common)

Adverse Reactions - Serious

Extrapyramidal symptoms (tremors, dystonia, akathisia) (Uncommon)
QT prolongation, arrhythmias (Rare)
Neuroleptic malignant syndrome (NMS) (Very rare)
Blood dyscrasias (e.g., leukopenia, thrombocytopenia) (Rare)

Drug-Drug Interactions

CNS depressants (enhanced sedation)
Other dopamine antagonists (risk of additive side effects)
CNS stimulants (opposite effects)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for effectiveness in controlling nausea and vomiting. Assess for extrapyramidal symptoms, sedation level, and cardiac status (EKG if indicated).

Diagnoses:

Risk for injury related to sedation or extrapyramidal symptoms.
Impaired comfort related to nausea.

Implementation: Administer with food to minimize gastric irritation. Use cautiously in elderly. Monitor cardiac status if on other QT-prolonging drugs.

Evaluation: Effectiveness of antiemetic action. Observation for adverse effects, especially extrapyramidal symptoms and cardiac arrhythmias.

Patient/Family Teaching

Take the medication exactly as prescribed.
Report any signs of unusual movement, muscle stiffness, or restlessness.
Be cautious when driving or operating machinery until effects are known.
Avoid alcohol and other CNS depressants during therapy.

Special Considerations

Black Box Warnings:

Increased risk of death in elderly patients with dementia-related psychosis.

Genetic Factors: Certain individuals may have genetic susceptibility to adverse reactions such as tardive dyskinesia.

Lab Test Interference: May cause false-positive tests for methemoglobinemia.

Overdose Management

Signs/Symptoms: Severe sedation, extrapyramidal symptoms, hypotension, seizures, respiratory depression.

Treatment: Supportive care; manage hypotension with vasopressors; treat seizures with anticonvulsants; gastric lavage or activated charcoal if ingestion recent.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F), protect from light.

Stability: Stable for the period specified in the package insert unless otherwise disturbed.