The resin of the wood of Guaiacum officinale, Linné, or of Guaiacum sanctum, Linné (Nat. Ord. Zygophyllaceae). West Indian trees. Dose, 5 to 30 grains.
Common Names: Resin of Guaiac, Guaiac.
Description.—Greenish, gray-brown fragments, masses or tears of a balsamic odor and slightly acrid taste. Usually admixed with fragments of vegetable tissues. Easily soluble in alcohol, ether and chloroform. Dose, 5 to 15 grains.
Principal Constituents.—Three resins: guaiaconic acid (70 per cent), guaiacic acid, and guaiaretic acid.
Preparations.—1. Specific Medicine Guaiacum. Dose, 5 to 30 drops.
2. Tinctura Guaiaci Ammoniata, Ammoniated Tincture of Guaiac (Guaiac, 20 per cent, in Aromatic Spirit of Ammonia). Dose, 10 to 30 drops.
Specific Indications.—Dryness and stiffness of the throat with tumid, swollen tonsils, painful deglutition and dribbling of saliva; incipient tonsillitis (early); rheumatic pharyngitis.
Action and Therapy.—External. The ammoniated tincture or the dilution of the specific medicine (1 to 3 of alcohol), added to water, acts efficiently as a gargle or preferably a wash, for the forms of sore throat mentioned below.
Internal. Guaiac once had considerable vogue as a remedy for syphilis, but is practically out of use in that disease at the present day. It was also much used in rheumatism, in which it has a better claim to efficiency. Guaiac is laxative, expectorant, and diaphoretic. When it fails to act upon the skin it usually stimulates the kidneys. Large doses may occasion gastro-intestinal inflammation. It has somewhat of an antiseptic action, which is extended to the secretions caused by it.
The chief uses for guaiac are in rheumatic pharyngitis or rheumatic sore throat and incipient tonsillitis, with angry, red, raw-looking surfaces, where the parts appear to be severely inflamed or greatly congested. The latter may be the type which is the forerunner of an attack of acute inflammatory rheumatism—the tonsils being the foci of infection. In such cases it acts better than in other forms of amygdalitis. While seemingly indicated in active conditions in sore throat and in chronic rheumatism, it is best adapted to passive conditions-cold hands and feet, feeble circulation, and vital depression. In general plethora or inflammation of the gastro-enteric tract it is usually contraindicated. Guaiac has been much employed in chronic sore throat of syphilitic origin. The best form of administration is a fourfold dilution of specific medicine, mixed with syrup and water. Stronger preparations than this diluted tincture precipitate heavily.
The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.