indication

For the controlled reduction of blood pressure during surgery and in the treatment of hypertensive emergencies.

pharmacology

Trimethaphan is indicated for production of controlled hypotension during surgery to reduce bleeding into the surgical field and also for rapid reduction of blood pressure in the treatment of hypertensive emergencies, especially in patients with acute dissecting aneurysm, and in the emergency treatment of pulmonary edema in patients with pulmonary hypertension associated with systemic hypertension.

mechanism of action

Trimethaphan is a ganglionic blocking agent prevents stimulation of postsynaptic receptors by competing with acetylcholine for these receptor sites. Additional effects may include direct peripheral vasodilation and release of histamine. Trimethaphan's hypotensive effect is due to reduction in sympathetic tone and vasodilation, and is primarily postural.