Derivation.—Aconite is obtained from the root of aconitum napellus, which grows in Northwestern North America, Europe and Asia in mountainous regions, and cultivated in the United States for its beautiful flowers.
Properties.—The fresh leaves have a faint narcotic odor, most sensible when they are rubbed. Their taste is at first bitterish and herbaceous, afterwards burning and acrid, with a feeling of numbness and tingling on the inside of the lips, tongue and fauces, which is very durable, lasting sometimes many hours. When long chewed they inflame the tongue. The dried leaves have a similar taste, but the acrid impression commences later. Their sensible properties and medical activity are impaired by long keeping. They should be of a green color, and free from mustiness. The root has a feeble earthy odor. Though sweetish at first, it has afterwards the same effect as the leaves upon the mouth and fauces. It shrinks much in drying and becomes darker, but does not lose its acrimony. Those parcels, whether of leaves or roots, should always be rejected which are destitute of this property. Aconite root is officially described as being “slenderly conical, 4 to 10 cm. long, 10 to 20 mm. thick at the crown; occasionally split; longitudinally wrinkled; dark brown and marked with coarse whitish root-scars; fracture short, horny or mealy; internally whitish or light brown; the cambium zone irregular and 5 to 7-angled; odor very slight; taste sweetish, soon becoming acrid and developing a tingling sensation, followed by numbness.”
Preparations of the leaves are not official in the U. S. P. The root is five times stronger than the leaves.
Constituents.—The alkaloid representing the action of the drug is aconitine, which is precipitated by ammonia from an aqueous solution of an alcoholic extract of the root of various species. It is a colorless, crystalline or amorphous, gray powder, almost insoluble in water, and soluble in 22 parts of alcohol, in 44 parts of ether and 1 part of chloroform. Its salts are soluble in water. Aconitine or its solutions, unless very dilute, are too poisonous to be tasted.
Commercial preparations vary in purity and strength, and since it is extremely poisonous its internal administration is undesirable. Pseudo-aconitine, aconitine and other alkaloids in combination with aconitic acid have been obtained from aconite, but their identity and chemistry are uncertain.
Dose.—Horses and cattle, 3 to 20 grs.; sheep and pigs, 1 to 3 grs.; dogs, 1⁄10 to 1⁄11 gr.
PREPARATIONS
FLUIDEXTRACTUM ACONITI—FLUIDEXTRACT OF ACONITE
Made by maceration and percolation with alcohol and water and evaporation. Assayed so that each 100 c. c. contains 0.4 gm. aconitine.
Dose.—Horses and cattle, 5 to 20 m.; sheep and pigs. 2 to 5 m.; dogs, 1⁄10 to 1 m.