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.
The further symptoms in fatal cases of belladonna-poisoning are swelling of the face, protrusion of the eyeballs, great inflation of the conjunctiva, coma, and convulsions; besides which narcotic phenomena, there are usually signs of irritation in the alimentary canal, pain in the belly, nausea, vomiting, and occasionally diarrhoea, which justify the designation of the drug as an "acro-narcotic." As regards the effects of belladonna on the pulse, there is a rather remarkable conflict of evidence. While many authors (especially Schroff,3 who made some 1,200 experiments) state that the pulse is at first diminished in frequency, and afterward (in the case of large doses) accelerated, Meuriot found constantly that in from eight to ten minutes after a subcutaneous injection of atropia there was an acceleration of the pulse, which lasted for one or two days, after which there followed a retardation. My own experience corresponds rather with the latter statement; but it is probable there are great differences in the affection of the pulse, according to the dose and the circumstances under which it is taken.
A summary of the more exact researches which have been made to determine the special physiological actions of belladonna and atropia on particular portions of the nervous centres, might lead us approximately to the following conclusions:
1. Large doses paralyze the peripheral ends of the motor nerves in striped muscles and the peripheral ends of the sensory nerves in the skin; the muscular irritability proper remaining intact.
1 Von Bezold and Bloebaum: Wurzburg. physiolog. Untersuch. i., p. 1, 1867
2 Meuriot, op. cit.
3 Lehrbuch der Pharmacologic.
2. Atropia depresses and in large doses paralyzes the peripheral ends of the cardiac branches of the vagus and the motor cardiac ganglia, and also depresses the irritability of the heart walls; it has no influence upon the cardiac depressor nerve.
3. Upon the vaso-motor nerves atropia acts in such a manner as to produce ultimate vascular dilatation; but whether this is direct, or secondary to contraction, is still in dispute.
4. Atropia paralyzes the terminals of the vagus in the lungs, but only temporarily, and increases the excitability of the inspiratory centres.
5. Atropia, in very small doses, diminishes excitability; in larger doses it produces paralysis in the ganglionic apparatus of the intestinal canal, the bladder, the uterus, the ureters, and possibly in the unstriped muscu-lai fibres themselves.
6. Atropia paralyzes the restraint influence of the splanchnics on the motor fibres which perform intestinal peristalsis,1 while all the other muscular fibres of the intestines are unaffected.
7. It paralyzes the restraint nerves from the chorda tympani to the sub-maxillary gland.2
Besides the above, which are phenomena of general belladonna-poisoning after absorption into the blood, there are some local influences which require mention. The local influence of atropia, applied directly to the eye, upon the pupil, has been noticed. The dilatation of the pupil is strictly one-sided, and usually there are no phenomena of irritation. But occasionally (as was first pointed out by George Lawson3) the local application causes irritative symptoms, which are apparently due to peculiarities in the subject of the medication; these are redness and chemosis of the conjunctiva, erysipelatoid swelling of the lids, lachrymation etc. More decided irritation has been noticed by Meuriot, after the application of collyria containing atropia, in the skin of the face, eczema, boils, etc. A more remote action (after the application of atropia to the eye), which seems to be conveyed through the nerves of the part to which the substance has been applied, is instanced by dryness and redness of the throat in man, and by salivation in cats. As regards the local action of belladonna upon the sensory nerves, we have the statement of Fleming that the inunction of atropia upon the unbroken skin produces no benumbing effect. But Erlenmeyer showed that the subcutaneous injection of atropia produces marked and rapid lowering of the cutaneous sensibility in the neighborhood of the puncture.
(The quantity of atropia required to dilate the pupil has been estimated by several observers. Dr. H. C. Wood states that a drop or two of a solution containing 1/20 grain to an ounce of water is sufficient in many cases. One drop of such a solution would contain about 1/10000 of a grain; but as the entire drop is probably not absorbed, the actual amount of effective atropia is indefinitely less. Dr. D. B. St. J. Roosa (manuscript communication to editor) states that he has seen dilatation result from 1/20000 of a grain, and Dr. Ely from 1/40000. Trousseau and Pidoux refer to an instance in which a dog's pupil was dilated for eighteen hours by the
1 (Other authors state the contrary. Vide Ott: Action of Medicines, p. 141.)
2 The above summary, which is only approximate, is taken from Husemann (Pflanz enstoffe), and is based on the experiments of a large number of authors.
3 Ophth. Hosp. Reports, ii., 2, 119.
1/128600 of a grain. Lastly, Dr. E. G. Loring, of this city, states (manuscript communication) that he has dilated his own pupil for twelve hours with the 1/460000 of a grain.)
Post-mortem examinations of the bodies of persons who have been poisoned by belladonna show that putrefaction commences very soon after death. The smell is peculiar and intolerable, and the skin is covered with livid spots, while blood escapes from the mouth, the nose, and the eyes. Should the whole substance of the berries have been swallowed (as usually happens in such cases of poisoning), they are found to be very imperfectly digested, in consequence of the poison inducing extreme torpor of the stomach. The heart and lungs are livid; the latter are usually gorged with venous blood, and studded with black spots; and the blood itself is in an abnormal state, seeming to be dissolved.