Related entry: Digitalis under diuretics
The leaves of Digitalis purpurea.—Europe.
Preparation.—Tincture of the recent plant.
Dose.—The dose will vary from the fraction of a drop to five drops.
Specific Indications.—A frequent pulse with enfeebled action of the heart, is the best indication. A feeble frequent pulse, with dusky flushing of both cheeks, has been thought to indicate the remedy; as has a frequent pulse with scanty urine.
Therapeutic Action.—Digitalis is sedative, narcotic, and diuretic. The views relative to its properties are discordant, and hence says a writer, "If any person were inclined to write a satire on medical evidences, the different testimonies respecting the properties of this single plant would furnish abundant materials. 'It is a diuretic,' says one. 'It is no diuretic,' says another. 'It is a stimulant,' says a third. 'It is no stimulant,' says a fourth; while a fifth contends that it has no properties at all."
In small and related doses, Foxglove sometimes affects the organic functions, producing disorder of the stomach, increase of urine, and alteration in the frequency, fullness and regularity of the pulse, etc., without affecting the cerebral functions.
The recumbent position greatly favors its sedative action. The pulse is found to be more frequent even in health in an erect than in the recumbent posture, and such is the case when under the influence of Digitalis.
One peculiarity in the action of Foxglove which merits especial notice, is its cumulative effect. By the continued use of small doses of the Digitalis no visible impression is made for a time, when suddenly and unexpectedly its poisonous effects will be developed with fearful and alarming violence, manifested by "great depression of the vascular system, giddiness, want of sleep, convulsions, and sometimes nausea and vomiting." Its constitutional effects thus developed, render its cautious administration, as to increase of dose and repetition, imperative.
In modern practice Aconite and Veratrum have taken the place of this remedy as an arterial sedative, being more certain and safer. Now it is employed principally as a "heart tonic," it being generally conceded that it exerts a stimulant influence upon this organ, which is somewhat permanent, and leads to an improved nutrition. Of course, for this purpose, the dose must be small, and usually it is associated with bitter tonics and the restoratives.
I can not recommend its use in fever or inflammation, as we have better and safer remedies. The same may be said as to its use in hemorrhage, and also as a diuretic in dropsy. In each of these cases we have direct and safer remedies.