Origin. - The dried bark of Rhamnus Purshiana D. C, collected at least one year before being used. Rhamnus Purshiana is a shrub or small tree 15 to 20 feet (4.5-6 M.) high, indigenous on the Pacific coast of North America from the British possessions southward to Northern California.

Description and Properties. - Quills or curved pieces about 1/4 to 4 inches (3-10 Cm.) long and about 1/12 inch (2 Mm.) thick; outer surface brownish gray and whitish, the young bark with numerous, rather broad, pale-colored warts; inner surface yellowish to light-brownish, becoming dark-brown with age; smooth or finely striate, fracture short, yellowish, in the inner layer of thick bark somewhat fibrous; inodorous; taste bitter.

The bark contains red, yellow, and brown resins, containing anthraquinone derivativesanthracenestannic, malic, and oxalic acids, a volatile oil, and possibly a glycoside, xantho-rhamnin or purshianin.

Dose. - 30-60 grains (2.0-4.0 Gm.) [15 grains (1 Gm.), U. S. P.].

Official Preparations

Fluidextractum Rhamni Purshianae Aromaticum - Fluidextracti Rhamni Purshianae Aromatici - Aromatic Fluidextract of Cascara Sagrada (U. S. P.). - This is the aromatic fluidextract of cascara sagrada of the National Formulary. It differs from the fluidextract, which was already official, in having an aromatic flavor and being devoid of the intensely bitter principle occurring in the bark.

Dose. - Average dose: 15 minims (1 Cc), U. S. P.

Extractum Rhamni Purshianae - Extracti Rhamni Purshianae - Extract of Cascara Sagrada (U. S. P.). - One part of the solid extract represents the activity of four parts by weight of the bark.

Dose. - Average dose: 4 grains (0.250 Gm. = 250 milligrammes), U. S. P.

[This represents 15 grains (1 Gm.) of the bark, and is equal to the Pharmacopoeial dose of the fluidextract - namely, 15 minims (1 Cc.).]

Physiological Action. - Cascara sagrada is a peculiarly efficient laxative, although in certain individuals it appears to be inert unless associated with other purgatives. The bitter principle it contains gives to the drug stomachic properties.

The action of cascara is seldom attended with irritation or unpleasant symptoms, the drug requiring from six to ten hours to operate.

Therapeutics. - Cascara is a very valuable laxative, being employed chiefly to overcome habitual constipation due to simple torpor of the colon without associated disease. The drug is not adapted for rapid evacuation of the bowels, but rather for regulating their action.

Administration. - The fluid and solid extracts are usually employed, although the cascara cordial and the aromatic fluidextract, while requiring larger doses, are so palatable that they have become deservedly popular.

Whatever be the preparation used in cases of habitual constipation, it should be given in small but repeated doses, gradually diminished until a natural action of the bowels shall have been established. The drug should be administered upon an empty-stomach and in as diluted a condition as possible.