This section is from the book "Materia Medica And Therapeutics - Vegetable Kingdom", by Charles D. F. Phillips. Also available from Amazon: Materia Medica And Therapeutics: Vegetable Kingdom.
1 Therapeutics and Materia Medica, 4th Ed., 1874, vol. i, p. 924.
Much more decidedly made out is the antagonism between belladonna and Calabar-bean, which, by the splendid researches of Dr. Fraser, has now been worked out in a manner that leaves little or nothing to be desired. The general nature of the facts elicited is fairly stated by Fraser2 in the following words: - "In presence of the many obvious proofs to the contrary contained in this paper, I have considered it superfluous to enter into any discussion of the possibility of this counteraction being the result of some chemical reaction between atropia and physostigma, or of an increased rapidity in the elimination of the one substance produced by the action of the other. The conditions of the experiments, and the symptoms that were observed, render it certain that atropia prevents the fatal effect of a lethal dose of physostigma, by so influencing the functions of certain structures as to prevent such modifications from being produced in them by physostigma as would result in death. The one substance counteracts the action of the other; and the result is a physiological antagonism so remarkable and decided that the fatal effect, even of three and a half times the minimum lethal dose of physostigma, may be prevented by atropia." It may be mentioned also that Professor Bartholow, of Cincinnati (though this was unknown to Fraser), had, in 1869, already investigated the opposition of atropia and physostigma; but he had only been able to find an antagonism between their actions as regards the organic nervous system, and did not reckon atropia an available antidote for physostigma-poison-ing. But the elaborate researches of Fraser, especially his more recent ones, leave not the slightest doubt of the practical applicability of atropia for this purpose.
Even more interesting than either of the above-named antidotal actions of atropia, is the power of antagonizing hydrocyanic acid, which was first assigned to it by W. Preyer3 in 1868. Preyer discovered that prus-sic acid kills by embarrassing the heart and respiration; and that this ef-
1 On the Antagonism between the Actions of Physostigma and Atropia, by Thomas R. Fraser. M.D., F.R.S.E. (Proceedings of Royal Society of Edinburgh, 1872). 2 Fraser, op. cit. 3 Die Blausaure physiologisch untersucht. See Review in Practitioner, voL i., 1868 feet is produced by an intense irritation of the inhibitory cardiac, and the pulmonary branches of the vagus. Atropia possesses the power of paralyzing these, and the result of this paralysis is to re-excite the action of the heart after it has been stopped by hydrocyanic acid. It is needless to say that this can only take place when the administration of the atropia is not too long delayed; so that the promptitude it calls for must often hinder the practical usefulness of this remedy. And it is right to mention that the experiments of Preyer as yet want full confirmation. The dose of atropia which he recommended in hydrocyanic acid poisoning is 1/15 grain, which should be subcutaneously injected; and as, in so desperate an emergency, every auxiliary ought to be employed, it should be remembered that artificial respiration has itself been found by Preyer to save animal life; and that (as Dr. Ringer remarks) the only thing necessary is to keep the patient alive during a short period, after which the poison will have become eliminated, and danger will cease. It is therefore right, when we-are called to a case of Prussic-acid poisoning, at once to set artificial respiration going, without waiting for the action of the atropia, which must occupy some time, be it ever so little.
I cannot conclude this brief notice of the singular antagonistic virtues of atropia without remarking that this modern addition to the other numerous excellences of belladonna which are available in medicine, raises this plant to an almost unexampled importance among remedies. With the single exception of opium, there is probably no vegetable medicine so important in existence; and already there seems a probability that many purposes to which opium has been applied will hereafter be found more efficiently discharged by belladonna.
For internal use atropia is dangerous. At first the dose should not exceed 1/100 of a grain; but subsequently it may be increased, with caution, to 1/30 grain, and in special (poison) cases even to 1/10 grain.
Preparations and Dose. - Tinct. Belladonnas, mv. - xxx. (.30 - 2.); Ext. Belladon., gr. 1/10 - 1/2 (.006 - .03); Ext. Bell. Alcoholicum idem; Ext. Bell. Fl., m i. - v. (.06 - .30); Ungt. Bell.; Suppos. Bell.; Emplast. Bell.; Atropia rarely used; Atropias sulphas, gr. 1/126 - 1/65 (.0005 - .001).