Toxicology

The symptoms of Calabar bean poisoning have all been stated above. The obvious antidote is atropine, which may often succeed; and the other measures are those usually employed to stimulate the circulation and respiration. Unfortunately the antagonism between physostigmine and atropine is not perfect, and Sir Thomas Fraser has shown that in such cases there comes a time when, if the action of the two drugs be summated, death results sooner than from either alone. Thus atropine will save life after three and a half times the fatal dose of physostigmine has been taken, but will hasten the end if four or more times the fatal dose has been ingested. Thus it would be advisable to use the physiological antidote only when the dose of the poison - assuming estimation to be possible - was known to be comparatively small.