Buckthorn berry (Rhamni cathartici fructus)

Published March 16, 1990; Replaced November 25, 1993.
List of German Commission E Monographs (Phytotherapy)


Name of Drug

Rhamni cathartici fructus, buckthorn berry.

Composition of Drug

Buckthorn, consisting of the dried ripe berries of Rhamnus catharticus L. [Fam. Rhamnaceae] as well as its preparations in effective dosage.

The drug contains anthranoids, mainly of the emodin type.

Pharmacological Properties, Pharmacokinetics, Toxicology

1,8-dihydroxyanthracene derivatives have a laxative effect. This works mainly through its effect on colon motility by inhibiting the stationary and stimulating the propulsive contractions. This results in faster bowel movements and a reduction of fluid absorption due to the shortened contact time. In addition, because of the stimulation of active chloride secretions, water and electrolytes are discharged.

Systematic research on the kinetics of buckthorn berry preparations are not available at present. However, it is assumed that the aglycones contained in the drug are absorbed in the small intestine. The ß-glycosides are prodrugs which are neither absorbed nor cleaved in the upper gastrointestinal tract. They are broken down into anthrones by enzymes in the colon. Anthrones are the laxative metabolites.

Active metabolites of other anthranoids such as cassic acid pass in small amounts into the milk of nursing mothers. A laxative effect on breast-fed babies has, however, not been observed. In animal experiments only a minimal level of absorption through the placenta has been observed.

Drug preparations [i.e., herbal stimulant laxatives] contain a higher level of general toxicity than the pure glycosides, probably due to the high level of aglycones. Research on the genotoxicity of the drug or of drug preparation are not available at present. Some positive results are available for aloe-emodin, emodin, parietin and chrysophanic acid. No research has been done on carcinogenicity.

Clinical Data 1. Uses Constipation.

2. Contraindications

Obstruction of the bowel or intestines, acute inflammatory conditions of the bowels such as Crohn's disease, colitis, appendicitis; abdominal pains of unknown origin; children under 12 years; pregnancy.

3. Side Effects

Some patients may suffer from gastrointestinal cramps. If this occurs, the dose should be reduced.

In the case of chronic use/overuse: loss of electrolytes, especially loss of potassium, albuminuria, hematuria. Pigment implantation into the intestinal mucosa (pseudomelanosis coli) is harmless and usually reverses upon discontinuation of the drug. The potassium deficiency can lead to disorders of heart function and muscular weakness, especially with concurrent use of cardiac glycosides, diuretics and corticoadrenal steroids.

4. Warning

Stimulating laxatives should not be used over an extended period (1 - 2 weeks) without medical advice.

5. Use During Pregnancy and Lactation

Not to be taken during pregnancy or lactation because of the lack of toxicological research.

6. Interactions with Other Drugs and Substances

With chronic use or in cases of abuse of the drug, a potentiation of cardiac glycosides due to a loss of serum potassium is possible. Also possible is an effect on antiarrhythmic agents. Potassium deficiency can be increased by simultaneous application of thiazide diuretics, corticosteroids, or licorice root.

7. Dosage and Mode of Administration

20 - 30 mg hydroxyanthracene derivative per day calculated as glucofrangulin A. The individual dose is the minimum required to produce a soft stool.

The crushed drug for infusions, boiling, cold macerations or elixirs. Liquid or solid form solely for oral administration.

Note: The method of dosing facilitates a smaller than average daily dose.

8. Overdosing

Electrolyte and fluid-regulating measures.

9. Special Precautions

Taking stimulating laxatives for longer than the recommended period can lead to intestinal sluggishness.

The treatment should be used only if a therapeutic effect has not been achieved through change of diet or use of a swelling agent [i.e., bulk laxative].

10. Effects on Operators of Vehicles and Machinery

None known.