A carminative is a remedy which tends to overcome flatulency, that is, distention of the stomach or colon with gas. The aromatics, which depend for their action upon a volatile oil or resinous constituent, form the great bulk of the class; but alcohol, the distilled liquors, chloroform, ether, ammonia, carbonic acid, as in mineral waters and champagne, and many other local irritants have strong carminative properties. We shall take up here the action of the aromatics.

Pharmacologic Action Of The Aromatics

Microorganisms. - They are antiseptic, some of them strongly so, as oil of eucalyptus. Their use as antiseptics, however, is very limited, because of their slight solubility in water. In infected tooth-cavities the dentists use oil of cloves or its stearopten, eugenol, or oil of cinnamon.

Skin And Mucous Membranes

They are general protoplasmic irritants, so are irritant to both skin and mucous membranes. Applied to the tongue they have a biting effect, and in the eye cause smarting. Rubbed into the skin they are rubefacient, i. e., produce local dilatation of the skin vessels, with redness and warmth of the part. It is probable that they also stimulate the sensory nerve-endings and later depress them, for there is more or less biting and tingling, followed in a number of instances by partial anesthesia or numbness. Peppermint and its stearopten, menthol, distinctly depress the sensory nerve-endings, but at the same time stimulate the ends of the temperature nerves which appreciate cold (Ioteyko, 1903), hence they give a combined feeling of numbness and coolness.

Alimentary Tract

Many of them are pleasantly aromatic, and these are used as flavors, especially in the dilute forms of the official waters and spirits. They tend to promote the appetite, but in undiluted form are irritant enough to induce a protective flow of saliva. In the stomach they are local irritants, and if given in sufficiently concentrated form, dilate the vessels and produce hyperemia, thus giving a feeling of well-being in the stomach region. At the same time they stimulate motor activity and the expulsion of accumulated gases. The less dilute they are, the more prompt is their action. It is generally believed that there is some stimulation of secretion, so that they are contraindicated in hyperacidity; but Korczynski (1901) found that from pepper and mustard there was not only no increased acidity or quantity of the gastric juice, but even a diminution. It may be that, like alcohol, they increase the gastric secretion through an action in the mouth. There seems to be some furtherance of absorption by the stomach, presumably owing to the active hyperemia. Thus the functions of motion and absorption are stimulated, but probably not that of secretion unless they promote appetite.

Hertz (1910) has observed by the x-rays that very promptly following the administration of a strong carminative by mouth colon peristalsis is set up. This is a reflex action, and it tends to cause the expulsion of accumulations of intestinal gas, and to overcome colic or griping. There is also a direct effect, Muir-head and Gerald finding marked stimulation of isolated segments when various oils were applied in dilutions of 1 to 50,000. These drugs are regularly added to irritant cathartics as "correctives."

Absorption is rapid from stomach and duodenum.

Nervous System

From the local irritation in the mouth or stomach there is a general reflex stimulation of the vasoconstrictor, the accelerator, and the respiratory centers, so that respiration is deepened and arterial pressure raised, and momentary feelings of faintness are overcome. In this way carminatives act as restoratives. There is also, after absorption, an apparent cerebral stimulation which may be effective in overcoming hysteria and other conditions of nervous instability.

Circulation

Besides the reflex stimulation, there is flushing of the skin from dilatation of the cutaneous arterioles.

Genital Organs

In strong doses these oils tend to be em-menagogue and abortifacient, and many of the cases of poisoning by pennyroyal, rue, savine, and tansy have come from attempts to produce miscarriage. Frequently the victim has died in agony without the abortion occurring, or has developed a severe colitis. Whether the influence on the genital organs could be a factor in overcoming hysteria has not been studied.

Elimination

Part is oxidized in the body, and the remainder is eliminated in the urine and the breath, mostly in more or less changed aromatic forms. For example, the odor of the breath of the whisky-drinker is not that of either alcohol, whisky, or fusel oil, but of a derivative of the fusel oil. The urine from turpentine has an odor of violets, and that after peppermint is strongly aromatic, but not minty. In the elimination there is a remote local irritant action on the kidneys and bronchi, with diuretic and expectorant effects. The urine may even be rendered antiseptic, but it is a question whether large enough amounts ever appear in the bronchial mucus to have an antiseptic value.

Toxicology

Poisoning results - (a) from the irritant ones in concentrated form, with local and systemic symptoms, or (b) from absorption, with systemic symptoms only. From the very irritant types there may be violent gastritis and colitis, with vomiting, diarrhea, and abdominal cramps, and perhaps vomiting of blood and bloody stools. From absorption there may be overstimulation of the cerebrum, with excitement, great restlessness, delirium, and perhaps cerebral convulsions, or there may be dizziness, stupor, and mental depression similar to that from alcohol or ether. These states may pass into collapse, coma, the convulsions of asphyxia, and death. The kidneys may be the seat of an acute nephritis. The treatment is to empty the stomach and administer demulcents, such as white of egg, milk, olive oil, and mucilaginous drinks, and to treat symptomatically for collapse. The inflammatory lesions must be treated as when they arise from other causes. After recovery from the acute symptoms there may be a chronic nephritis or colitis. Poisoning has been reported from asafetida, nutmeg, mustard, and a great many of the aromatics. The colitis cases have mostly resulted from the emmenagogue oils taken for abortifacient purposes.