Emetics

Emetics, medicines given for the purpose of producing Vomiting (q.v.). They are given when it is desirable to relieve the stomach of some noxious or indigestible substance, such as a narcotic poison, or excess of food, or some special article of diet which has disagreed. Emetics are also administered in cases of fever, where the copious secretion they produce from the glands of the stomach and intestines is supposed to have a directly curative effect, aided, perhaps, by the sedative action of emetics upon the circulation and nervous system. There is a considerable amount of evidence to show that emetics have the power of cutting short typhus and other fevers in the earliest stage, and afterwards of making the attack of the disease less severe. In diseases of the respiratory organs, emetics are given as the quickest and safest method of removing accumulated mucus from the air-passages; and in Croup (q.v.) their action is especially favourable, being often followed by expectoration and a rapid improvement in the suffocative symptoms. Emetics are to be given with great caution, however, in all very depressed states of the system, as their primary action is to produce nausea, which is attended always with more or less diminution of the vital power, and often with great depression of the heart's action, amounting to syncope or fainting. Emetics may produce vomiting either by their local action on the throat, guttlet, and stomach, or by their action through the blood on the nervous mechanism regulating the movements of the stomach. They are thus divided into two groups, local and general emetics; and the depressing effect of the former is much less than that of the latter. Some substances will produce vomiting in either way; so that the distinction between the two classes is not very definite. Among the chief emetics in use are mustard (two tablespoonfuls), common salt (a tablespoonful or more), alum (a teaspoonful), in a tumblerful of water, repeated after a quarter of an hour if necessary. These, with sulphate of copper or zinc, are mainly local in their action; ipecacuanha and emetin, squills, senega, tartar emetic and other soluble salts of antimony, apomorphia, are mainly general in their action. The production of vomiting is aided, whatever emetic is used, by copious draughts of warm water. Tickling the throat with a finger or feather is often an effective mechanical means to produce vomiting.