Some NSN-Tris-Quaternary Neuromuscular Blocking Agents

Abstract

Abstract The tris-quaternary compounds 7-ethyl-7-thioniatridecylenebis(triethylammonium) triiodide (Dihexasulphonium triethiodide; DHSE), 6-ethyl-6-thioniaundecylenebis(triethylammonium) triiodide (Dipentasulphonium triethiodide; DPSE), and 7-methyl-7-thioniatridecylenebis(trimethylammonium) triiodide (Dihexasulphonium trimethiodide; DHSM) have been synthesised. DPSE and DHSE have been shown to be neuromuscular blocking agents, which act by a mechanism resembling that of tubocurarine and gallamine rather than decamethonium. DPSE and DHSE are about equipotent with tubocurarine on the cat gastrocnemius muscle, but less potent on the frog rectus abdominis muscle and rat diaphragm, and the head drop doses are higher. Neuromuscular block can be reversed by neostigmine, eserine, and edrophonium. DHSE and DPSE do not cause ganglion blockade or histamine release, do not increase heart rate and are less potent than tubocurarine in causing respiratory paralysis.