[499] Med. Times, 1868.
[500] Lancet, vol. i., 1881, p. 414.
[501] Ibid., vol. i., 1876, p. 346.
[502] In an English case of belladonna poisoning, the patient, a tailor, sat for four hours, moving his hands and arms as if sewing, and his lips as if talking, but without uttering a word.
Chronic poisoning by atropine may, from what has been stated, be of great importance in India. It is probable that its continuous effect would tend to weaken the intellect, and there is no reason for any incredulity with regard to its power as a factor of insanity. Rossbach has ascertained that if dogs are, day after day, dosed with atropine, they become emaciated; but a certain tolerance is established, and the dose has to be raised considerably after a time to produce any marked physiological effect.
§ 451. Physiological Action of Atropine.—From the numerous experiments on animals which have been performed for the purpose of elucidating the action of atropine, it is clear that the terminations of the vagus in the heart muscle are first excited, and then paralysed. The excitor-motor ganglion is also paralysed, and finally the heart itself; death resulting from heart paralysis. The respiratory disturbance is also to be ascribed to the vagus; the terminations in the lung are paralysed, and, at the same time, the poison circulating through the respiratory nervous centre stimulates it first, and then it also becomes finally paralysed. The small vessels are generally widened after a previous transitory narrowing. Organs containing unstriped muscular fibre are generally paralysed, as well as the ends of the nerves regulating secretion—hence the dryness of the skin. The action on the iris is not thoroughly elucidated.
§ 452. The diagnosis of atropine poisoning may be very difficult unless the attention of the medical man be excited by some suspicious circumstance. A child suffering from belladonna rash, with hot dry skin, quick pulse, and reddened fauces, looks not unlike one under an attack of scarlet fever. Further, as before mentioned, some cases are similar to rabies; and again, the garrulous delirium and the hallucinations of an adult are often very similar to those of delirium tremens, as well as tomania.
§ 453. Post-mortem Appearances.—The post-mortem appearances do not seem to be characteristic, save in the fact that the pupils remain dilated. The brain is usually hyperæmic, and in one case the absence of moisture seems to have been remarkable. The stomach and intestines may be somewhat irritated if the seeds, leaves, or other parts of the plant have been eaten; but the irritation is not constant if the poisoning has been by pure atropine, and still less is it likely to be present if atropine has been administered subcutaneously.
§ 454. Treatment.—The great majority of cases recover under treatment. In 112 cases collected by F. A. Falck, 13 only were fatal (11·6 per cent.). The greater portion of the deaths in India are those of children and old people—persons of feeble vitality. The Asiatic treatment, which has been handed down by tradition, is the application of cold water to the feet; but the method which has found most favour in England is treatment by pilocarpine, a fifth of a grain or more being injected from time to time. Pilocarpine shows as perfect antagonism as possible; atropine dries, pilocarpine moistens the skin; atropine accelerates, pilocarpine slows the respiration. Dr. Sydney Ringer and others have published a remarkable series of cases showing the efficacy of this treatment, which, of course, is to be combined where necessary with emetics, the use of the stomach-pump, &c.[503]