STUDIES IN MYASTHENIA GRAVIS

Since 1934, with the discovery of the value of cholinergic drugs for myasthenia gravis,¹the treatment for this disease has been the use of analogues of physostigmine. The first of these, neostigmine, has long been the undisputed drug of choice.²It has both an anticholinesterase (antiChE) and an anticurare action at the neuromuscular junction. Because of this dual action, neostigmine has been effective for the treatment of the greater majority of patients with this disease, especially for the patients with the milder types of myasthenia gravis for whom relatively small doses of neostigmine are necessary. It is in the more severe types that neostigmine has a distinct disadvantage because of its short duration of action. Because of the increased amount and frequency of dosage, cholinergic side-effects become pronounced and difficult to control despite the use of atropine. These side-effects are either muscarinic or nicotinic in action, causing increased