Senna pod (Sennae fructus)

Published July 21, 1993.
List of German Commission E Monographs (Phytotherapy)


Name of Drug

Sennae fructus acutifoliae, Alexandrian senna pod.
Sennae fructus angustifoliae, Tinnevelly senna pod.

Composition of Drug

Alexandrian senna pod consists of the dried fruits of Cassia senna L. (C. acutifolia Del. [syn. Senna alexandrina]) [Fam. Fabaceae], as well as their preparations in effective dosage.

Tinnevelly senna pod consists of dried fruits of C. angustifolia Vahl [Fam. Fabaceae], as well as its preparations in effective dosage.

Ed. note: Currently accepted nomenclature for both cultivars is Senna alexandrina Miller.] --> Sufficient pharmacological-toxicologic studies are available for preparations containing 1.4 - 3.5 percent anthranoids (calculated as sum of individually determined compounds), equivalent to 0.9 - 2.3 percent potential rhein, 0.05 - 0.15 percent potential aloe-emodin and 0.001 - 0.006 percent potential emodin.

The drug must conform to the currently valid pharmacopeia.

Pharmacological Properties, Pharmacokinetics, Toxicology

1,8-dihydroxy-anthracene derivatives have a laxative effect. This effect is due to the sennosides, i.e., their active metabolite in the colon, rheinanthrone. The effect is primarily caused by the influence on the motility of the colon by inhibiting stationary and stimulating propulsive contractions. This results in an accelerated intestinal passage and, because of the shortened contact time, a reduction in liquid absorbed through the lumen. In addition, stimulation of the active chloride secretion increases the water and electrolyte content of the stool.

Systematic studies pertaining to the kinetics of senna fruit preparations are not available. However, it must be supposed that the aglycones contained in the drug are already absorbed in the upper small intestine. The ß-glycosides are prodrugs that are neither absorbed nor cleaved in the upper gastrointestinal tract. They are degraded in the colon by bacterial enzymes to rheinanthrone. Rheinanthrone is the laxative metabolite. The systemic availability of rheinanthrone is very low. Animal experiments revealed that less than 5 percent is passed in the urine in the oxidized form and/or in conjugated form as rhein and sennodine. The major amount of rheinanthrone (more than 90 percent) is bound to the feces in the colon and excreted as polymers.

Active metabolites, such as rhein, infiltrate in small amounts into the milk ducts. A laxative effect on nursing infants has not been observed. The placental permeability for rhein is very small, as was observed in animals.

Drug preparations have a higher general toxicity than the pure glycosides, presumably due to the content of aglycones. Experiments with senna leaf preparations are not available. A senna extract showed mutagenic toxicity in vitro; the pure substance, sennoside A, B, was negative. An in vivo study with a defined extract of senna fruit revealed no mutagenicity. Preparations with an anthranoid content of 1.4 - 3.5 percent were used (calculated as the sum of specific individual compounds) that were potentially equivalent to 0.9 - 2.9 percent rhein, 0.05 - 0.15 percent aloe-emodin and 0.001 - 0.006 percent emodin. The results appear to be also applicable for specific senna leaf preparations. Some positive results have been observed for aloe-emodin and emodin. A study for carcinogenicity was performed with an enriched sennoside fraction containing about 40.8 percent anthranoids, of which 35 percent were sennosides (calculated as sum of the individually determined compounds), equivalent to about 25.2 percent of the calculated potential rhein, 2.3 percent potential aloe-emodin and 0.007 percent potential emodin. The tested substance contained 142 ppm free aloe-emodin and 9 ppm free emodin. The study was conducted over 104 weeks. Rats received up to 25 mg/kg body weight and showed no substance-dependent increase of tumors.

Clinical Data 1. Uses Constipation.

2. Contraindications

Intestinal obstruction, acute intestinal inflammation, e.g., Crohn's disease, colitis ulcerosa, appendicitis, abdominal pain of unknown origin. Children under 12 years of age.

3. Side Effects

In single incidents, cramp-like discomforts of the gastrointestinal tract. These cases require a dosage reduction.

With chronic use or abuse:

Disturbance of electrolyte balance, especially potassium deficiency, albuminuria and hematuria. Pigment implantation into the intestinal mucosa (pseudomelanosis coli) is harmless and usually reverses on discontinuation of the drug. Potassium deficiency can lead to disorders of heart function and muscular weakness, especially with concurrent use of cardiac glycosides, diuretics, and corticosteroids. 4. Special Caution for Use Stimulating laxatives must not be used over a long period (more than 1 - 2 weeks) without medical advice.

5. Use During Pregnancy and Lactation

During the first trimester of pregnancy, senna pod preparations should be used only if a therapeutic effect cannot be obtained with a change in diet or through the use of swelling laxatives. Active metabolites, such as rhein, infiltrate into the milk ducts. A laxative effect on nursing infants has not been observed.

6. Interactions with Other Drugs

In cases of chronic use or abuse, loss of potassium may potentiate cardiac glycosides and have an effect on antiarrhythmic medications. Potassium deficiency may be exacerbated by simultaneous administration of thiazide diuretics, corticosteroids, or licorice root.

7. Dosage and Administration

Comminuted herb, powder or dried extracts for teas, decoctions, cold macerates, or elixirs. Liquid or solid forms of medication exclusively for oral use.

Unless otherwise prescribed:

20 - 30 mg hydroxyanthracene derivatives daily, calculated as sennoside B.The individually correct dosage is the smallest dose necessary to maintain a soft stool. Note: The form of administration should be smaller than the daily dose.

8. Overdosage

Electrolyte and fluid imbalance.

9. Special Warnings

Use of a stimulating laxative for longer than the recommended period can cause intestinal sluggishness.

This preparation should be used only if no effects can be obtained through changes in diet or use of bulk-forming products.

10. Effects on Operators of Vehicles and Machinery

None known.