THE HAZARD OF CHOLINERGIC CRISIS DURING TREATMENT OF MYASTHENIA GRAVIS WITH OCTAMETHYL PYROPHOSPHORAMIDE

Abstract

Certain of the alkyl phosphates exert a powerful anticholinesterase effect. In the treatment of myasthenia gravis, octamethyl pyrophosphoramide has a distinct advantage in that it inactivates the cholinesterase of peripheral ganglia, muscles and glands but does not inactivate the cholinesterase of the central nervous system, so that there is no central stimulation incident to its use. It has the disadvantage that this inactivation of cholinesterase seems to be more or less permanent and is hence conducive to a cumulative effect which may produce a cholinergic state of profound degree, dangerous to life. When the "cholinergic" state develops gradually, there is a striking superficial similarity to its physiological opposite, the "myasthenic" state. Differentiation of these two is of extreme importance and should be possible on clinical grounds if the following criteria are observed (1) Both doctor and patient should be fully aware of the superficial similarity in symptomatology of cholinergic and myasthenic crises. (2) The paradox of regression without obvious provocation on adequate or increasing medication should lead to strong suspicion of a cholinergic state. (3) The coincidence of sialorrhea, sudorrhea and lacrimation, the muscarinic effects of acetylcholine intoxication will tend to confirm suspicion. (4) The therapeutic test of atropine sulfate gr. 1/50 intraven., should cause rapid and marked improvement in cholinergic crisis.