Pulsatilla consists of the dried herb, Anemone Pulsatilla, Linn. (N.O. Ranunculaceae), a plant indigenous to Great Britain. The herb possesses a stout, somewhat woody rhizome, producing a rosette of stalked leaves, and an erect scape bearing a whorl of three bracteoles, which form an involucre below the solitary terminal flower. The leaves are bipinnate, the ultimate lobes being linear, and the petioles often purplish. The flower possesses six light purple sepals, silky on the outside, and bracteoles divided to tire base in linear segments. The fruits are small brown, hairy achenes, with long (3.5 centimetres) feathery tails. The whole plant, especially the bases of the petioles, is clothed with silky hairs; it is odourless, but possessing when fresh a very acrid taste, which is less conspicuous in the dried herb, and gradually diminishes on keeping.
Constituents.—The chief active constituent of pulsatilla is a crystalline camphor, soluble in ether or chloroform, which possesses vesicant properties, and gives off an intensely irritating vapour. It is slowly converted into acrid crystalline anemonin and tasteless crystalline isoanemonic acid, the change taking place more rapidly in the presence of water. Anemonin is crystalline, tasteless, and odourless when pure, and melts at 152°. It is volatile in water vapor and is then irritating to the eyes and mouth.
Action and Uses.—The action of pulsatilla is virtually that of the crystalline substance anemonin, which is a powerful irritant like cantharides, an overdose causing violent gastro-enteritis, haematuria, and later anuria. It has been given as a "sedative" in dysmenorrhoea, although from its irritant action during excretion it must tend to excite the uterus reflexly, like cantharides. It has been employed for the relief of headache and neuralgia; but there is no reliable evidence of its value. The dose of anemonin is from 1 to 4 milligrams (1/60 to 1/15 grain). A tincture of pulsatilla is prepared, and recommended for use in dysmenorrhoea and amenorrhoea, in small doses frequently repeated.
- Extractum Pulsatillae Liquidum, B.P.C.—LIQUID EXTRACT OF PULSATILLA. 1 in 1.
- Dose.—1 to 3 decimils (0.1 to 0.3 milliliters) (2 to 5 minims).
- Tinctura Pulsatillae, B.P.C.—TINCTURE OF PULSATILLA. 1 in 10.
- Taken in small repeated doses for amenorrhoea and dysmenorrhoea. Dose.—3 to 20 decimils (0.3 to 2.0 milliliters) (5 to 30 minims).