This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
The therapeutics of the ipecac alkaloids having been given, it remains to say somewhat of ipecac itself.
Ipecac is a safe emetic, though depressing, at least transiently. The emetic dose is 15 grains, though less is usually effective. Fl. is emetic in 15-minim doses; syrup, 4 fluidrachms. In laryngismus stridulus it is the best emetic available, while in acute indigestion it is also the emetic of choice.
On the other hand, minute doses (1-10 to 1-5 minim fl.) often relieve nausea and vomiting, particularly of the type in which there is defective or deficient secretion from irritated mucous membranes in the gastrointestinal tract. For the same reason, in the diarrheas of infancy, these small doses, especially when combined with small doses of aconite, have a most happy effect, but only in the first or acute stage.
In the treatment of dysentery ipecac is better given in the powder or "Alcresta" ipecac, true amebic dysentery usually requiring emetine, q. v. Minute doses are not effective. Also see "Chaparro."
In respiratory diseases ipecac is a peculiarly valuable expectorant in spasmodic croup, dry cough, bronchitis, and other states requiring an increase and liquefaction of the bronchial mucus secretion. The expectorant dose of the fl. is one minim; other preparations in proportion. The syrup, in 10- to 15-minim doses, or the wine, in the same dose, serve admirably.
As a diaphoretic, ipecac, used in the form of Dover's Powder, in 10-grain doses, is exceedingly valuable in the early stages of catarrhal inflammations of the respiratory passages, and in the initial stages of many fevers, even of malaria, as it seems to prepare the system for quinine. Small doses are given as a remedy in night-cough.