This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
It is the hydrochlorate of an artificial Alkaloid obtained by heating Morphine sealed tubes with an excess of Hydrochloric Acid. The Morphine loses one molecule of water thus: C17H19No3=C17H17No2+H2O.
Minute, grayish-white, shining, acicular crystals, hav ing a faintly bitter taste, and acquiring a greenish tint on exposure to light and air.
In 45 parts of water; in about 45 parts of Alcohol.
Dose, 1/25 to 1/6 gr.; .0027 to .01 gm. hypodermatically, 1/20 to 1/10 gr.; .003 to .006 gm. by the mouth.
Gastro-intestinal tract. - Apomorphine is the most powerful emetic we possess. It does not act locally on the stomach, but solely on the vomiting centre in the medulla. It is therefore an indirect emetic. This is shown by the fact that when the drug is injected subcutaneously it produces violent vomiting if the vessels are so tied that none can reach the stomach, but not if they are so tied that it cannot reach the medulla.
Circulation. - Therapeutic doses have no effect beyond the depressing action which may be attributed to the vomiting. Large doses cause a rise in the rate of the pulse, probably from stimulation of the accelerator nerves, and with fatal doses the pulse-rate falls, because the drug directly paralyzes the cardiac muscle.
Respiration. - This is at first stimulated by the act of vomiting. The effect of poisonous doses is doubtful; probably they depress respiration. Physiological experiments show that it produces a watery discharge from the blood-vessels of the respiratory mucous membrane, which is found to be paler after the administration of this remedy, as well as less oedematous. This effect is produced within a half hour after ingestion, and it is not in any respect the first stages of emesis.
Nervous system. - The first result of toxic doses is to cause delirium. Finally there is paralysis of the motor nerves, and consequently of the muscles.
Vomiting action. - The advantages of apomorphine over the other emetics are that it is certain, prompt, and powerful; it can be given when emetics introduced directly into the stomach would not act, and it does not irritate the stomach. It is largely used in cases of poisoning. It is usually given hypo-dermatically, dissolved in camphor water; 1 in 50. Dose, 4 to 8 minims; .25 to .50 c.c. This must be prepared extemporaneously, as it will not keep.
Expectorant action. - It is, when given by the mouth, a valuable expectorant for bronchitis. In an adult 1/32 gr., .002 gm., or 1 dr., 4. c.c., of the syrup (see below) will produce a watery expectoration within the time above stated, and this effect will last from two to three hours. It is particularly useful in the early stages of acute bronchitis, in chronic dry bronchitis, in chronic catarrhal pneumonia, and in old tuberculous patients who are harassed by an unproductive cough.
Soporific action. - Recently it has been claimed that when given hypodermatically at bedtime, in dose just short of producing emesis, sleep, closely approaching the normal, ensues. This is not always the case, and its hypnotic action may be due to contamination with other alkaloids.
The British Pharmaceutical Conference recommends the following Syrup of Apomorphine: Mix Rectified Spirit, 84; with the same amount of water; dissolve in this Apomorphine Hydrochlorate, 1; add Diluted Hydrochloric Acid, 24; and finally Syrup, 1728 parts. Dose, 1/2 to 1 fl. dr. 2. to 4. c.c. The drug may also be given as a lozenge.