Related entry: Digitalis Leaves
Synonym.—Digitalinum Pulverisatum Purum Germanicum.
Digitalin of commerce is a preparation obtained from the leaves Of Digitalis purpurea, Linn., and consists of true digitalin mixed with a large proportion of amorphous digitonin and a smaller proportion Of the substance or mixture of substances known as digitalein. It occurs as a yellowish-white powder, which is free from odour, but has a bitter taste. Various other substances and mixtures are known under the name "digitalin" (see Digitalis Folia), but the mixture of glucosides here described contains the chief constituents of digitalis leaves, with the exception of digitoxin, and should usually be dispensed when "digitalin" is ordered in prescriptions.
Soluble in water and in alcohol, but almost insoluble in chloroform or ether.
Action and Uses.—Digitalin has the action of digitalis leaves, but is not cumulative. On account of its ready solubility in water it is specially suitable for subcutaneous use, and it is almost exclusively employed in the preparation of hypodermic tablets and solutions. It has been pointed out that the doses given in this country are much too small. In Germany, from 6 to 30 milligrams (1/10 to ½ grain) has been given three or four times daily in pills or tablets. It has been calculated that 15 minims of tincture of digitalis is approximately represented by ⅕ grain of commercial digitalin. In America a dose of 15 milligrams (¼ grain) has been used for some months without harm, and, in emergency, 30 milligrams (½ grain) every two hours for a few doses. In cases of poisoning by digitalin, the antidotes described under Digitalis Folia should be employed.
Dose.—2 to 15 milligrams (1/32 to ¼ grain), increased to 30 milligrams (½ grain).