Nurses Compass
Drug Guide
Trimethaphan Camsylate
Classification
Therapeutic: Antihypertensive, Neuromuscular Blocker
Pharmacological: Nicotinic Cholinergic Antagonist
FDA Approved Indications
- Control of blood pressure during hypertensive emergencies, especially during surgery or anesthesia
Mechanism of Action
Trimethaphan blocks nicotinic acetylcholine receptors at autonomic ganglia, leading to a rapid and reversible blockade of autonomic transmission, resulting in vasodilation and decreased blood pressure.
Dosage and Administration
Adult: Initial doses typically range from 15-30 mg IV, titrated based on blood pressure response.
Pediatric: Dosing in pediatric patients is individualized; consult specific pediatric guidelines.
Geriatric: Start at lower doses with careful titration due to increased sensitivity.
Renal Impairment: Adjust dose based on clinical response and tolerability.
Hepatic Impairment: No specific adjustment; use caution as hepatic metabolism may be affected.
Pharmacokinetics
Absorption: Administered intravenously; rapid onset.
Distribution: Widely distributed, crosses the blood-brain barrier minimally.
Metabolism: Metabolized in the liver.
Excretion: Excreted primarily via the kidneys.
Half Life: Approximately 4-8 minutes, depending on dosage and blood flow.
Contraindications
- Known hypersensitivity to trimethaphan or related compounds.
- Obstructive coronary artery disease.
- Lactation.
Precautions
- Use with caution in patients with cerebral hemorrhage, impaired kidney or liver function, or arrhythmias. Monitor closely for cardiovascular stability during therapy.
Adverse Reactions - Common
- Hypotension (Common)
- Tachycardia (Common)
- Reflex tachycardia and arrhythmias (Possible)
Adverse Reactions - Serious
- Seizures (rare) (Rare)
- Anaphylaxis (rare) (Rare)
Drug-Drug Interactions
- Other antihypertensives, especially agents affecting autonomic function.
- Agents that prolong QT interval.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor blood pressure, heart rate, and rhythm closely during administration.
Diagnoses:
- Ineffective tissue perfusion related to hypotension.
- Risk for decreased cardiac output.
Implementation: Administer IV slowly and titrate to desired blood pressure. Have resuscitative equipment ready.
Evaluation: Assess if blood pressure stabilizes within target range without adverse effects.
Patient/Family Teaching
- Report any symptoms of dizziness, fainting, or rapid heartbeat.
- Follow instructions on medication administration and monitoring.
Special Considerations
Black Box Warnings:
- Hypotension and cardiac arrhythmias can be severe; continuous monitoring required.
Genetic Factors: No specific genetic considerations.
Lab Test Interference: May affect blood pressure readings during administration.
Overdose Management
Signs/Symptoms: Severe hypotension, bradycardia or tachycardia, arrhythmias.
Treatment: Discontinue drug; provide supportive care including vasopressors or anticholinergics as indicated; manage arrhythmias per ACLS protocols.
Storage and Handling
Storage: Store at room temperature, protected from light.
Stability: Stable until expiration date when stored properly.