Hexamethonium bromide

Class Ganglionic blocker
Chemistry

bis-quaternary ammonium compound

Routes of administration

IV, IM

Absorption

Poor GI absorption, perhaps 25% of the oral dose is absorbed

Solubility

Highly water soluble; does not cross the blood brain barrier; high pKa

Distribution

VOD = 0.23 L/kg

Metabolism

Minimal metabolism

Elimination

Half life is about 10 minutes; most of the dose (close to 100%) is excreted in the urine

Time course of action

Duration of action is about 2 hrs

Target receptor

Nicotinic acetylcholine receptors... Except, "While selective for the ganglia in vivo, its in vitro potency at muscle and neuronal nAChRs is similar"

Mechanism of action

Blocks ganglionic autonomic neurotransmission, therefore decreasing both sympathetic tonic input to the vascular smooth muscle, and to the myocardium. Also blocks vagal neurotransmission.

Clinical effects

Vasodilation (arterial and, presumably, venous) without compensatory tachycardia, as well as ileus, bladder atony, and pupil dilation

Literature reference

Mason, 1980

CICM details of understanding Not specifically listed in the CICM syllabus
Mentioned around Deranged Physiology
Related SAQs