Action Of Ipecacuanha

External

Ipecacuanha powder is a powerful irritant to the skin, producing redness, vesication, and pustulation. It has some antiseptic powers, for it can destroy anthrax bacilli, but it has no effect on the spores. This property is not due to its emetine, but to some other constituent.

Internal

Alimentary canal. - Here also the irritating action of ipecacuanha is seen. It increases the flow of saliva, dilates the gastric vessels, and stimulates the secretion of gastric juice. Therefore small doses are distinctly stomachic, and aid digestion. Large doses are, however, powerfully emetic. This is partly due to their irritant effect upon the stomach, but still more to the fact that emetine acts directly upon the vomiting centre in the medulla, as can be proved by observing that, when the alkaloid is thrown directly into the circulation, vomiting follows before there is time for it to have been excreted into the stomach. Ipecacuanha is, therefore, both a direct and indirect emetic. It produces a certain amount of depression, but not more than the mere act of vomiting will explain. It does not usually cause nausea. The irritant effect is continued in the intestine, and hyperaemia, excessive secretion, and purging result. In dysentery there is a peculiar tolerance of ipecacuanha. Ipecacuanha increases the amount of bile secreted, and is therefore a direct cholagogue.

Circulation. - Large doses of emetine depress the heart powerfully, the blood tension falls, and the heart finally stops in diastole.

Respiration. - This is unaffected. Ipecacuanha powder when inhaled, or ipecacuanha taken internally, when it is excreted by the bronchial mucous membrane, causes hyperaemia of it, together with an increased secretion of bronchial mucus, and therefore, reflexly, coughing is stimulated. It is, consequently, an expectorant; and because it depresses the circulation a little, it is called a depressant expectorant; but this is a complete misnomer, considering that the bronchial mucous membrane is stimulated. Animals to which large doses of ipecacuanha or of emetine have been given show, after death, considerable hyperaemia of the bronchial mucous membrane, of the lungs, and of the stomach and intestines, and the same . condition of the respiratory passage is seen if ipecacuanha powder has been inhaled.

Skin. - Ipecacuanha is a mild diaphoretic.

Therapeutics Of Ipecacuanha

External

Ipecacuanha is never, at the present day, employed for its external irritant effect. It has been used with success, as an antiseptic, in cases of anthrax. It is directed that the wound should be dressed with the powder, and that 5 gr. .30 gm. should be taken by the mouth, every two hours.

Internal

Stomach. - Occasionally in small doses, such as 4 or 5 minims .25 to .30 c.c. of the wine or 1/4 gr. .015 gm. of the powder, it is employed as a stomachic, and these quantities may even stop vomiting when other drugs have failed. . A usual prescription to arrest the vomiting of pregnancy is a minim .06 c.c. of ipecacuanha wine in water every half hour. The powder of ipecac and opium has been praised in cases of gastric ulcer; no doubt any good effect it may have is due to its stimulating power. Ipecacuanha is a very common emetic. It should not be given when it is desired, as in cases of poisoning, to empty the stomach quickly, for some time elapses before it is absorbed and influences the medulla; nor should it be given to the very feeble, for it has no action that will counteract the depression of the vomiting. But it is an excellent emetic when it is wished, by the act of vomiting, to empty the air-passages, as in bronchitis, the early stages of diphtheria, tracheitis, and laryngitis, for not only the vomiting, but the effect of ipecacuanha on the respiratory tract and the slight subsequent depression will be beneficial. It is chiefly employed for this purpose in children, as they cannot cough well, and often it seems to act like a charm. It used to be given in the early stage of fevers, to empty the stomach of undigested food. A good emetic powder for an adult consists of 20 gr. 1.20 gm. of powdered ipecacuanha with 1/2 gr. .03 gm. of tartar emetic

Ipecacuanha is said to be a specific for dysentery. How it acts is not known. Very large doses must be given - 60 to 90 gr. 4. to 6. gm. of the powder in a single dose, or 20 gr. 1.20 gm. every four hours. Ipecacuanha from which the emetine has been removed (de-emetized ipecacuanha) has been much employed (dose, 10 to 30 gr. .60 to 2.00 gm.); on the other hand, it has been stated that the efficient agent in the treatment of dysentery is the emetine.

Half a grain to a grain .03 to .06 gm. or more is often combined in a pill with other cholagogues to relieve cases of hepatic dyspepsia, and sometimes with excellent results.

Respiration. - Ipecacuanha is a very common expectorant. The troches may be dissolved in the mouth or the syrup, or wine may be given internally. It is suitable in cases of bronchitis or phthisis in which the secretion is scanty, and therefore there is much purposeless cough; and also when the disease is of long standing, for then the stimulation of the chronically inflamed mucous membrane will aid the cure of it. Its power of exciting the act of coughing adds to its usefulness. Cephae-line seems to possess the expectorant properties of ipecacuanha.

The inhalation of ipecacuanha powder or wine by means of an atomizer has been recommended in cases of asthma, and for the asthma-like paroxysms which often accompany chronic bronchitis. Sometimes it does good, but it may make the trouble worse.

Skin. - Dover's powder see p. 352 is very commonly used as a diaphoretic in mild feverish attacks.