To the Editor.
—Since the introduction of neostigmine in 1934 by Mary Walker in the treatment of myasthenia gravis, various other anticholinesterase (cholinergic) drugs have been used in the treatment of this disease with varying success. Some of these, such as diisopropyl fluorophosphate (DFP), tetraethyl pyrophosphate (TEP), and octamethyl pyrophosphoramide (OMPA), produced long depression of the serum cholinesterase, depression lasting for from several days to several weeks. The most successful for treatment of myasthenia was octamethyl pyrophosphoramide, but this drug is no longer available because of the tremendous difficulties and dangers in its manufacture. With all of these drugs, as well as with neostigmine, the side-effects of intense stimulation of the gastrointestinal tract made it difficult to obtain a good therapeutic result in some patients unless belladonna derivatives were given with each dose of the anticholinesterase compound. When this was done, the gastrointestinal effects disappeared, but at the same time