This section is from the "A Handbook of Useful Drugs" book, by State Medical Examining and Licensing Boards.
The hydrochlorid of an artificial alkaloid prepared from morphin by the abstraction of one molecule of water.
Properties : Apomorphin hydrochlorid occurs as minute, grayish-white prisms, having a slightly bitter taste and acquiring a greenish tint on exposure to light and air. It is soluble in both water and alcohol. If the salt imparts at once an emerald-green color to 100 parts of water it should be rejected. The amorphous form may contain dangerous impurities.
Incompatibilities: It is precipitated by alkalies and the other alkaloidal reagents. Solutions decompose rather readily.
Action and Uses: The chief action of apomorphin is the production of vomiting with its usual accompanying symptoms, including nausea with increase of saliva and other secretions, depression of the circulation, sweating, etc. It sometimes produces respiratory paralysis, even in small doses.
The drug is used chiefly as an emetic. For this purpose it has the advantage that it acts on the vomiting center, independently of a local action on the stomach. It produces a prompt emptying of the stomach with little subsequent sickness, unless the dose is large. It is therefore a useful emetic in poisoning, if the stomach-tube cannot be employed. It has been advised for the expulsion of foreign bodies from the air-passages. As an expectorant it is inferior to other nauseants.
It is said to be sometimes useful in asthma. Small doses (0.002 gm., 1/30 grain) are hypnotic, especially in acute alcoholism.
Dosage: The emetic dose is 0.005 gm. or 1/10 grain, given preferably by hypodermic injection. This may be repeated at ten-minute intervals until effective, but it should be remembered that in some cases apomorphin produces toxic effects without causing vomiting, and a dose of 0.004 gm. or 1/15 grain is said to have produced death in a person enfeebled by chronic bronchitis; 0.012 or 1/5 grain may be given to robust patients at the first dose if the urgency of the case demands it, but care should be exercised in the use of these doses.
As an expectorant the proper dose is from 0.001 gm. to 0.002 gm. or from 1/60 to 1/30 grain, repeated once an hour or once in two hours, with the avoidance of more than slight nausea.