Nurses Compass
Drug Guide
Trimethobenzamide Hydrochloride
Classification
Therapeutic: Antiemetic
Pharmacological: Peripheral dopamine receptor antagonist
FDA Approved Indications
- Nausea and vomiting
Mechanism of Action
Trimethobenzamide blocks dopamine receptors in the chemoreceptor trigger zone (CTZ) in the brain, reducing nausea and vomiting sensations.
Dosage and Administration
Adult: Typically 200-400 mg orally three times daily. Adjust based on response and tolerability.
Pediatric: Use as per pediatric dosing guidelines; usually 4.5-7.5 mg/kg/day divided into three doses.
Geriatric: Start at lower doses due to increased sensitivity and decreased metabolism; monitor closely.
Renal Impairment: Adjust dose as needed, with cautious use; no specific guidelines, consider renal function tests.
Hepatic Impairment: Use with caution; no specific dosing guidelines available, monitor liver function.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed in body tissues.
Metabolism: Primarily hepatic; undergoes hepatic metabolism.
Excretion: Renal excretion of unchanged drug and metabolites.
Half Life: Approximately 6-12 hours.
Contraindications
- Hypersensitivity to trimethobenzamide or related compounds.
- Presence of Parkinson's disease or other movement disorders.
Precautions
- Use with caution in patients with hepatic impairment, in elderly, and in those with a history of seizures. May cause drowsiness or dizziness, caution during activities requiring alertness.
Adverse Reactions - Common
- Drowsiness or sedation (Common)
- Dizziness (Often)
- Dry mouth (Common)
Adverse Reactions - Serious
- Extrapyramidal symptoms (parkinsonism, dystonia) (Rare)
- Seizures (Rare)
- Allergic reactions (rash, urticaria, anaphylaxis) (Rare)
Drug-Drug Interactions
- Centrally acting sedatives, other CNS depressants, anticholinergic drugs.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor patient for effectiveness, side effects, and signs of adverse reactions such as extrapyramidal symptoms.
Diagnoses:
- Risk for falls due to dizziness or sedation.
- Impaired mobility related to extrapyramidal symptoms.
Implementation: Administer with food if gastrointestinal upset occurs. Monitor neurologic status regularly.
Evaluation: Assess for resolution of nausea and any adverse effects; adjust dosing accordingly.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report any unusual movements, drowsiness, or allergic reactions.
- Avoid alcohol and CNS depressants while using this medication.
Special Considerations
Black Box Warnings:
- Avoid use in patients with Parkinson’s disease or history of movement disorders.
Genetic Factors: None established.
Lab Test Interference: May interfere with certain diagnostic tests that evaluate movement disorders.
Overdose Management
Signs/Symptoms: Severe CNS depression, extrapyramidal symptoms, seizures.
Treatment: Supportive care, symptomatic management, activated charcoal if ingestion is recent, and benzodiazepines for seizures.
Storage and Handling
Storage: Store at room temperature away from moisture and light.
Stability: Stable for recommended shelf life, check manufacturer's guidelines.