Origin. - The hydrochloride of an alkaloid prepared from morphine by the abstraction of one molecule of water.

Description and Properties. - Minute, grayish-white, shining, acicular crystals, without odor, having a faintly bitter taste, and acquiring a greenish tint upon exposure to light and air. Soluble in about 39.5 parts of water and about 38.2 parts of alcohol. It should be kept in small, dark amber-colored vials. If the preparation imparts to 200 parts of water when slightly shaken an emerald-green color, the drug should be rejected.

Dose. - 1/20-1/10 (0.003-0.006 Gm.) by the mouth; 1/25-1/5 grain (0.0025-0.01 Gm.) hypodermically [1/30 grain as expectorant (0.002 Gm.); 1/10 grain as an emetic (0.005 Gm.), U. S. P.].

Physiological Action. - Externally and Locally. - None.

Internally. - Digestive System. - From five to twenty minutes after ingestion - according to the dose and the manner of administration - vomiting ensues, being repeated three or four times at intervals of about fifteen minutes. The emesis is preceded and attended by a slight nausea, with but moderate depression. Apomorphine is a typical direct or systemic emetic, its entire action being exerted upon the medulla. It is perhaps the most powerful and certain emetic we possess. So far as its systemic action is concerned, its relation to morphine should be remembered.

Nervous System. - Full doses stimulate the brain and may even occasion delirium. Apomorphine frequently causes unconsciousness and may be used as a hypnotic, like morphine. Convulsions have been observed when given in large doses.

Circulatory System. - Small doses have no perceptible effect upon 'the circulation. Full doses increase the rapidity and force of the heart's action and raise arterial pressure, owing to stimulation of the accelerator nerves and vasomotor center. Large or toxic amounts depress the circulatory system or paralyze the cardiac muscle.

Respiratory System. - Small amounts do not affect the respiratory movements, although the secretion from the bronchial mucous membrane is increased. Full doses accelerate and deepen respiration, while toxic amounts cause depression, as does morphine.

Absorption and Elimination. - Apomorphine is readily absorbed, and is excreted through the gastro-intestinal tract, as well as by the bronchopulmonary mucous membrane, the kidneys, and the skin.

Temperature is unaffected by small doses, but may be lowered by large amounts.

Poisoning. - The symptoms would be violent vomiting, delirium, or convulsions, and marked cardiac and respiratory depression, death resulting from asphyxia.

Treatment of Poisoning. - As that of morphine-poisoning.

Therapeutics. - Apomorphine is the most reliable emetic to use when prompt emesis is necessary or in cases where swallowing is difficult or impossible.

It is extremely useful as an emetic in cases of poisoning, though it frequently happens in narcotic poisoning that the vagus center is so blunted by the poison that apomorphine fails to act. Should it be necessary to provoke emesis when the stomach is in a state of acute inflammation, apomorphine is preferable to any other emetic.

Given by the mouth in small doses - from 1/40 grain (0.001 Gm.) to 1/20 grain (0.003 Gm.) every three or four hours - this drug is an exceedingly efficient remedy in acute bronchitis. It is equally beneficial in relieving the dry, hacking cough of chronic bronchitis, chronic catarrhal pneumonia, and tuberculosis.

Apomorphine in small doses has often proved a serviceable hypnotic.

Contraindications. - The same as for emetics generally. It is contraindicated in morphine-poisoning.

Administration. - Apomorphine when given as an emetic should invariably be administered hypodermically, and the solution be always freshly prepared. When the drug is used as an expectorant it should be given by the mouth. Great care should be taken in administering the drug to children, as they bear it badly.