Cascara Sagrada - Drug Interactions, Side Effects and Precautions of Use

Taxonomic Class

Rhamnaceae

Common Trade Names

Multi-ingredient preparations: Bassoran with Cascara, Bicholax, Cas-Evac, Casvlium, Kondremul with Cascara

Common forms

Available as capsules, bitter and sweet fluidextracts, powders, and dried

bark for teas. Cascara sagrada prepared as a tea is not popular because of its extremely bitter taste and the availability of standardized pharmaceutical preparations that perform the same functions.

Source

Cascara sagrada is the dried bark of Rhamnus purshiana. It should be aged for at least 1 year before use in medicinal preparations, but 3-year­old bark is preferred for pharmaceutical purposes because it exhibits a milder cathartic activity because of the oxidation of glycosides present in the bark. Cascara sagrada is found in the Pacific Northwest, from Canada to California.

Chemical Components

Two types of anthracene compounds-emodin glycosides (O-glyco­sides) and aloinlike C-glycosides-have been reported. The C-glycosides are divided into barbaloin, deoxybarbaloin (chrysaloin), and the cascarosides. Dried, medicinal-quality cascara bark yields not less than 7% of total hydroxyanthracene derivatives, calculated as cascaroside A, on a dried basis. The cascarosides should make up at least 60% of this total. Actions

The glycosides found in cascara sagrada are stimulant cathartics that exert their action by increasing the smooth-muscle tone in the wall of the large intestine and have only minor effects on the small intestine. The drug is transformed by intestinal bacteria into substances that in­crease peristalsis in the large intestine and help restore intestinal tone.

Reported Uses

Cascara sagrada was traditionally used as a laxative by Native Americans of the Pacific Northwest. In 1990, the FDA released the results of its study on OTC products and placed cascara sagrada in category I (safe and effective) as a laxative . Dried, aged cascara sagrada bark is widely accepted as a mild and effective treatment for chronic constipation .

Dosage

Aromatic fluidextract (sweet cascara): 5 ml P.O.

Extract capsules: 300 mg EO.

Liquid extract (bitter cascara): 1 to 5 ml P.O.

Adverse Reactions

• GI: abdominal pain.

• EENT: allergic rhinitis.

• Respiratory: IgE-mediated asthma. Chronic use or abuse

• GI: abdominal cramps, diarrhea, melanosis coli (darkening pigmentation of colonic mucosa), steatorrhea, vomiting.

• GU: urine discoloration.

• Metabolic: fluid and electrolyte imbalance, vitamin and mineral defiCiencies.

• Musculoskeletal: osteomalacia.

• Other: laxative dependency.

Interactions

None reported, but the absorption of some drugs may be diminished.

Contraindications And Precautions

Cascara sagrada is contraindicated in pregnant or breast-feeding patients because it crosses the placental barrier, is excreted in breast milk, and increases the risk of diarrhea in a breast-fed infant. Although cascara sagrada may be used cautiously during pregnancy, other laxatives (such as bulk-forming and surfactant laxat ives) may be preferred.

Special Considerations

• Effective bowel regimens for constipation include temporary pharmacotherapy together with maintaining sufficient fluid intake and hydration, increasing fiber in the diet, eating regular meals, and exercising.

• Patients with chronic constipation (longer than 1 week) should be evaluated by a primary health care provider for underlying causes of obstruction.

• Cascara sagrada appears to be reasonably safe, although the fresher the bark, the higher the risk of adverse reactions. Occupational exposure of pharmacy workers to cascara sagrada has resulted in IgE-mediated asthma and allergic rhinitis .

• Inquire about laxative use when taking the drug history.

• Inform the patient that the FDA has determined that cascara sagrada is generally safe and effective.

• Advise women to avoid using cascara sagrada during pregnancy or when breast-feeding.

• Inform the patient that cascara sagrada products are for short-term use.

Points of Interest

Cascara sagrada mostly comes from Oregon, Washington, and southern British Columbia. During the summer, sections of bark are peeled off and rolled into large quills. The bark is then carefully sun-dried so that the inner surface is not exposed to the sun and its yellow color is retained. The drug is then processed into its final form.

Commentary

Cascara sagrada is a mild stimulant laxative that is safe and effective. Although the FDA has approved its use, caution should be used when treating chronic constipation to avoid laxative dependency. Reliable and standardized pharmaceutical forms are preferred because there is no advantage in using the bark as a tea for its medicinal effects. Standardized pharmaceutical products ensure correct dosage and minimize the risk of adverse reactions.