Cathartics

These alkaloids include the substituted pyridone ricinine [524-40-3] (53), CgHgN202, which is easily isolated in high yield as the only alkaloid from the castor bean (Ricinus communis L.). The castor bean is also the source of castor oil (qv), which is obtained by pressing the castor bean and, rich in fatty acids, has served as a gentie cathartic. 

Phenolphthaleia is a cathartic dmg and the basis of many OTC laxatives. Its action is mainly on the colon to produce a soft semifluid stool within six to eight hours. Its action may persist for several days owiag to enterohepatic circulation and it may cause red urine if urine is alkaline. 

Cascara sagrada is used as a cathartic. It is most useful when prepared as a fluid extract, and tends to be a mild laxative causing Htfle discomfort. However, on prolonged use it may result in characteristic melanotic pigmentation of the rectal mucosa. The bitter taste can be lessened, owing to neutralization of the acid constituents, if the ground substance is moistened and mixed with magnesium or calcium hydroxide. This treatment may lessen the potency of the preparation. 

Castor oil is a cathartic only after Hpolysis in the small intestine Hberating ricinoleic acid. Ricinoleic acid inhibits the absorption of water and electrolytes. It is commonly used for preparation of the large bowel for diagnostic procedures. 

Magnesium sulfate heptahydrate may be prepared by neutralization of sulfuric acid with magnesium carbonate or oxide, or it can be obtained directly from natural sources. It occurs abundantly as a double salt and can also be obtained from the magnesium salts that occur in brines used for the extraction of bromine (qv). The brine is treated with calcium hydroxide to precipitate magnesium hydroxide. Sulfur dioxide and air are passed through the suspension to yield magnesium sulfate (see Chemicals frombrine). Magnesium sulfate is a saline cathartic. 

Salts. Rochelle salt is used in the silvering of mirrors. Its properties of piezoelectricity make it valuable in electric oscillators. Medicinally, it is an ingredient of mild saline cathartic preparations, eg, compound effervescing powder. In food, it can be used as an emulsifying agent in the manufacture of process cheese. 

Sodium sulfate in moderation is used as a diuretic and cathartic for humans and animals (14) (see Gastrointestinal agents). It is also used in consumer products such as laxatives, antacids, and as a natural filler it is used extensively in powdered laundry detergents (see Detergency). 

Sodium carboxymethylcellulose is Hsted in the 1990 United States Pharmacopeia under the categories of pharmaceutic aid (suspending agent, tablet binder, viscosity-increasing agent), and cathartic tablets. 

CociEana, the dried bark of Guana rusbji (Britt.) Rushy, was probably first used by the natives of the BoUvian Andes as an emetic—cathartic. It is often prescribed as an alternative to ipecac in the treatment of cough, and the emetic side effects at high doses suggest a mechanism of action similar to that of ipecac. 

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