Botanical name: 

Source and Composition. Ipecac is the root of Cephaëlis Ipecacuanha, a Brazilian shrub of the nat. ord. Rubiaceae. It contains a crystalline alkaloid Emetine, a glucoside Ipecacuanhic Acid, also gum, starch, etc, and a trace of a volatile oil. Dose, of the powdered root as an expectorant, gr. ss-ij;—as an emetic, gr. xv-xxx.

Preparations. The principal ones are—

Extractum Ipecacuanhae Fluidum, Fluid Extract of Ipecac,—Dose, ♏j-v.
Vinum Ipecacuanhae, Wine of Ipecac,—10 per cent.,—Dose, ♏j-ʒj.
Syrupus Ipecacuanhae, Syrup of Ipecac,—7 per cent.,—Dose, ʒj-iv.
Pulvis Ipecacuanhae et Opii, Dover's Powder,—has of Ipecac 10, Pulvis Opii 10, Sugar of Milk 80 parts. Dose, gr. ij-xv, or xx.
Tinctura Ipecacuanhae et Opii, Liquid Dover's Powder,—has of Tinct. Opii Deod. 100 evaporated to 80, Fluid Extract of Ipecac 10, Diluted Alcohol to 100. Dose, ♏ij-xv, or xxx.
*Emetina, Emetine,—a crystalline alkaloid, odorless, bitter, white, nearly insoluble in water, but with acids forming salts which are readily soluble. An energetic poison in large dosage. Dose, as an expectorant, gr. 1/120-1/40; as an emetic, gr. 1/8-1/4.

Physiological Action. Ipecac is nauseant, emetic, expectorant, cholagogue, diaphoretic, hemostatic, sternutatory and counter-irritant. Locally, applied to skin or mucous membrane, it acts as an irritant, and may cause pustulation. Inhaled as a powder, it excites violent sneezing and reflex mucous secretion; on some persons having an especially irritant action, so that the most infinitesimal quantity by inhalation will in them induce an asthmatic paroxysm. In the stomach it irritates the mucous membrane and the vagus terminations, and causes prompt emesis. Absorbed into the blood it excites the vomiting centre in the medulla, producing the same result. In medicinal doses it increases the mucous secretions in a marked degree, and is slightly diaphoretic. Small doses (gr. 1/8-1/4) act as a stomachic tonic and stimulant to the gastric secretions. Emetic doses repeated result in tolerance on the part of the stomach, when catharsis is set up, the stools having a peculiar "grass-green" color, a bilious character, and looking as if they were fermented. By continuance of the drug the intestinal canal will also acquire tolerance,—the cathartic action ceasing. Emetine causes death in animals by cardiac paralysis; the autopsies showing evidences of intense gastro-intestinal irritation, also hyperaemic lungs with patches of hepatization.

Antagonists, Antidotes, etc. The emetic action is antagonized by the Narcotics generally, also by Bismuth, Carbolic and Hydrocyanic Acids.

Incompatibles are salts of Lead and Mercury, Vegetable Acids and astringent infusions.

Therapeutics. As an emetic Ipecac is much used, being safe, non-depressant, and sure, though somewhat slow. It is also employed as an expectorant in bronchitis when the secretion is scanty, and as an antihemorrhagic and an antidysenteric. It is generally administered in—

Bilious Headache, acute indigestion, and similar conditions,—gr. iv of the powder in warm water, or a teaspoonful of the syrup, every 1/4 hour until emesis occurs,—to empty the overloaded stomach.
Fevers, at their commencement,—an Ipecac-vomit is very serviceable in the eruptive, continued and malarial fevers.
Laryngismus Stridulus, Spasmodic Croup, etc.,—the Syrup is a favorite emetic, which generally cuts short an attack if given early and freely.
Dysentery, of the tropics especially,—is best treated by Ipecac in large doses (gr. xx-xxx every 4 hours) pushed to tolerance.
Vomiting, especially when of nervous origin,—small doses (♏j) of the wine, frequently repeated, will relieve in many cases, perhaps through a sedative influence on the vagus.
Coughs at night, also in Acute Catarrh and Bronchitis,—it is a very efficient remedy;—also in Hay Fever and Spasmodic Asthma, in all of which slight nauseation must be produced before relief will be experienced. The wine, as a spray, is highly recommended in winter cough and bronchial asthma.
Jaundice from catarrh of the bile-ducts,—Ipecac to lessen the viscidity of the mucus stopping up the ducts.
Rheumatism, muscular or acute,—Dover's powder is useful.

A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.