Hexafluorenium inhibits the enzyme cholinesterase in the plasms, but apparently not at the neuromuscular juntion. It also has some nondepolarizing activity (tubocurarine-like) at the postjunctional membrane. In man hexafluorenium potentiates the muscle relaxant effects of succinylcholine. As such, smaller doses of succinylcholine are required and fewer side effects like fasciculations, twitching and postoperative muscle pain are experienced.