trimethaphan (Arfonad)

Introduction

Tradename: Arfonad.

Dosage

• 500 mg 100 mL D5W (5 mg/mL) IV at 1-10 mg/min (12-120 mL/hr).
• IV infusion 0.5-4 mg/minute.

Adverse effects

• tachyphylaxis to this drug tends to develop within 24 hours of use
• adynamic ileus
• acute urinary retention
• muscle paralysis with respiratory failure

• drug adverse effects of antihypertensive agents

Mechanism of action

Trimethaphan's effects are directed at the sympathetic ganglia. Its major advantages over other drugs in treatment of hypertensive crisis is a reduction of both BP & shear forces on the aortic wall. Thus trimethaphan is considered an alternative first line agent in the treatment of aortic dissection.

More general terms

• adrenergic neuron inhibitor

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=441310
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=23576