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.
As an appendix to the article on opium and its alkaloids, it is neces-sary to give a description of the new substance apomorphia, which, though not a natural constituent of opium, has been obtained by treating morphia in a particular manner. In 1869 it was discovered by Matthiessen and Wright that, by heating morphia for two or three hours in a closed tube, with large excess of hydrochloric acid, the result was the formation of water and a new substance - Apomorphia,
Ihe new substance is precipitated with bicarbonate of soda, and the precipitate removed with chloroform or ether. The chloroform or ether solution is treated with concentrated hydrochloric acid, and chloride of apo-morphia becomes deposited on the sides of the vessel; it is afterwards precipitated by bicarbonate of soda. Pure apomorphia is a snow-white substance, rapidly changing to green upon contact with the atmosphere: when it has become green it is partially soluble in water and in alcohol, forming in either case a beautifully colored solution; the ethereal and chloroformic solutions, on the other hand, are respectively purple-red and violet. The chloride of apomorphia also assumes a green color upon contact with atmospheric air or on heating; probably from oxidation.
The therapeutic action of this new substance proves to be widely different from that of any of the original constituents of opium. The investigations of Dr. Gee,1 from which I have copiously extracted, show that it is an extremely prompt and certain provoker of vomiting. The experiments were made with the chloride, since the base itself is exceedingly unstable. One-fifth of a grain taken by a healthy man produced dizziness and depression in twenty minutes, an uncomfortable sensation in the head, and nausea, without the least somnolence. The patient then became very pale and salivated; in twenty-five minutes after the dose he vomited freely; after vomiting twice he felt much relieved, drank half a glass of wine, and in half an hour regained his usual condition. Subcutaneous injection of 1/10 grain of the chloride in a healthy adult produced similar sensations, and free vomiting in ten minutes. Subsequently Dr. Hensley produced vomiting in a drunken man in three minutes, by injecting 1/5 grain; he also produced vomiting in a drunken woman in three minutes by injecting 1/10 of a grain, and in a drunken man in six minutes by fa grain.
There are reasons for thinking that, over and above the production of vomiting, apomorphia may act as a contra-stimulant or antiphlogistic sedative.
Given in large doses to brute creatures, chloride of apomorphia was found to produce grave nervous symptoms. Two grains were injected into a dog; the animal vomited, in two or three minutes began to run round and round the room in a curiously persistent and methodical manner, and in the end recovered completely. Three grains injected into a cat produced greater excitement. Besides the running round, there were occasional high leaps and somersaults; the pupils were dilated to the extreme, and became insensible. Two more grains produced epileptiform convulsions; and upon the injection of yet two more, making seven in all, the convulsions were followed by perfect relaxation, the heart beat somewhat forcibly, and next morning the creature was found dead. All the organs were found in a perfectly natural condition: there was no hyperaemia of any one of them. Only once has anything similar been observed in the human subject. This occurred with a man who was under treatment for chronic morbus Brightii, and who had on each of two succesgive days taken the emetic draught of the hospital pharmacopoeia without effect. A day or two after he was injected with 1/10 gr. of apomorphia. In four minutes he vomited freely. The vomiting continued at intervals for half an hour; he then passed into a mildly delirious state for half an hour, after which he went to sleep for an hour; when he awoke he felt, according to his own account, better than before the injection.
1 Clinical Trans., vol. ii.
It is interesting to remark that, although the action of small doses of apomorphia on man is so extremely unlike that of small doses of morphia, the poisonous action of large doses of these alkaloids upon cats is very similar. Dr. Anstie has observed 1 that wide, fixed dilatation of the pupil is an invariable and early-produced symptom of morphia-poisoning in the cat; and he informs me that, with the exception of the vomiting, every symptom described by Dr. Gee is produced in cats by morphia in very large doses. I have already mentioned that morphia produces epilepsy in dogs. There are sundry expectations, as yet not sufficiently grounded on fact, that apomorphia may prove antagonistic to tetanus. Whether this hope will prove well founded or not, it is certain that in apomorphia a very valuable medicine has been secured, its emetic powers being ex-traordinarily active, and the emesis itself being followed by no nausea, and only by very transient depression. The entire freedom from any ten-dency to irritate the subcutaneous tissues gives to apomorphia much ad-ditional value.