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.
Bloodroot, Sanguinaria Canadensis. Official only in the U. S. The chemical composition is complex, the principal proximate being sanguinarine, which belongs to the morphine group. It causes depression of the respiratory center. Sanguinaria is an acrid emetic with narcotic properties. In smaller doses it is a stimulating expectorant. In quite small doses its action, like that of other emetics, is largely upon the mucous membranes generally, thus giving it a probably unwarranted reputation as an alterative.
Sanguinaria is used externally in the treatment of cancer; but, in my opinion, such use is no more warranted than is that of other mild escharotics.
In large doses the drug is a certain emetic, very harsh in action and giving rise to marked depression.
Fatal collapse has followed its use. As an emetic sanguinaria is, very properly, being abandoned.
As a stimulant expectorant this drug serves a useful purpose if judgment is used in prescribing it. One should feel his way as regards dosage; but some cases of asthma, acute bronchitis, and catarrhal subacute bronchitis are very markedly benefited by doses of from 1/2 to 2 minims fl., or 5 to 20 minims of the tincture. Just remember that sanguinaria is a positive expectorant; then use it wisely, and you will come to esteem it as a useful drug that has gone into unmerited retirement.
In somewhat smaller doses - fl.1/4 to 1 minim - sanguinaria is of value in laryngitis, especially in the irritable type. Or one can use Sanguinarine Nitrate in doses of 1-20 to 1-12 grain in syrup of wild cherry. In nasal catarrh with free secretion, both the alkaloid and the tincture are quite available remedies.
Bartholow advocated the use of sanguinaria as an hepatic stimulant, and rationally so; but we have much better agents for this purpose.
In very small doses, varying with different individuals, sanguinaria is an excellent tonic in cases of gastro-intestinal functional disorders marked by lack of secretion.
A decoction, or a faintly colored solution of sanguinarine nitrate, acts admirably as a stimulating gargle in sore throat.