RHAMNUS PURSHIANA, or Californian buckthorn, a plant the bark of which is used in medicine under the name of cascara sagrada. An active principle anthra-gluco-sagradin has been isolated by Tschirch. The preparations of it contained in the British pharmacopoeia are: (i) Extractum cascarae sagradae (extractum rhamni purshianae, United States pharmacopoeia), dose 2 to 8 grs.; (2) Extractum cascarae sagradae liquidum, dose $ to i fl. dr. From the latter is prepared syrupus cascarae aromaticus, dose 5 to 2 fl. dr. In this preparation the bitter taste of the cascara sagrada is disguised by the addition of tincture of orange, cinnamon water and syrup. In the United States pharmacopoeial preparation Fluid extractum rhamni purshianae aromaticum, does 10 to 30 minims, the taste is similarly obscured. Cascara sagrada is one of the most useful of all laxatives, since not only does it empty the bowel of faecal matter, but it acts as a tonic to the intestine and tends to prevent future constipation. It is largely used in the treatment of chronic constipation. A single full dose of the liquid extract may be taken at bedtime, or divided doses, 10 to 15 minims, three times a day before meals. When a strong purgative is required some drug other than cascara sagrada should be employed, but its use in gradually decreasing doses is indicated after evacuation has been effected by podophyllin or rhubarb. Cascara sagrada is the principal constituent of most of the proprietary laxatives on the market.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)