Senna glycoside, also known as sennoside or senna, is a medication used to treat constipation and empty the large intestine before surgery. The medication is taken by mouth or via the rectum. It typically begins working in minutes when given by rectum and within twelve hours when given by mouth. It is a weaker laxative than bisacodyl or castor oil.

Pursennid A and B increase intestinal motility through release of active anthraquinones into the colon by colonic bacteria. Purified sennosides (sennosides A and B) are used similarly to senna.

Senna stimulates peristalsis and increases fecal water content to increase motility of feces through the large intestine.

Senna stimulates peristalsis and increases fecal water content to increase motility of feces through the large intestine.


It is used to treat hard stools (constipation).

Pursennid is also used to associated treatment for these conditions: Constipation, Hemorrhoids, Auto-intoxication, Meteorism

How Pursennid works

Sennoside A and B, the components of senna, are metabolized by gut bacteria into the active metabolite rheinanthrone Rheinanthrone. Rheinanthrone Rheinanthrone appears to increase cyclooxegenase 2 (COX2) expression in macrophage cells leading to an increase in prostaglandin E2 (PGE2). This increase in PGE2 is associated with a decrease in aquaporin 3 expression in mucosal epithelial cells of the large intestine. A decrease in aquaporin 3 expression likely produces the laxative effect by restricting water reabsorption by the large intestine thereby increasing fecal water content. The exact mechanism by which rheinanthrone increases COX2 expression is unknown. Rheinanthrone Rheinanthrone also stimulates peristalsis in the large intestine although the mechanism behind this effect is unknown. Rhein Rhein, another active metabolite is thought to excite submucosal acetylcholinergic neurons resulting in increased chloride and prostaglandin secretion. The movement of chloride ions into the large intestine would also help to draw water into the lumen.


Trade Name Pursennid
Generic Sennosides
Sennosides Other Names Senna glycosides, Sennoside, Sennosides
Formula C42H38O20
Weight Average: 862.746
Monoisotopic: 862.195643624
Protein binding

Because sennosides are ingested and their action occurs in the gut, it is generally not thought to be protein bound.

Groups Experimental
Therapeutic Class Osmotic purgatives
Available Country Switzerland
Last Updated: June 7, 2022 at 8:55 pm


Sennosides Structure


Pursennid dosage


  • Adult: 15-30 mg (as total sennosides) 1-2 times daily.
  • Child: 2-6 yr: 3.75-7.5 mg once daily in the morning; 6-12 yr: 7.5-15 mg once daily at night or in the morning; ≥12 yr: 15-30 mg at bedtime.

Bowel evacuation

  • Adult: 105-157.5 mg of sennosides on the day before the procedure. May be given as a liquid preparation.

Side Effects

Mild abdominal discomfort e.g. colic and cramps; diarrhoea, hypokalaemia and atonic non-functioning colon (prolonged use); reversible melanosis coli (chronic use). May colour the urine yellowish-brown at acidic pH or red at alkaline pH.


Senna causes increased amounts of apoptosis in the large intestine shortly after use due to upregulated p53 activity. This is normally reversed after 18 hours however chronic use has been shown to be associated with p53 resistance and potential carcinogenicity leading to colon cancer. The LD50 value in rats was 5000mg/kg. Subacute studies in rats receiving 20mg/kg and dogs receiving 500mg/kg did not produce signs of toxicity. Tests for mutagenicity and reproductive toxicity do not indicate toxic effects.

Pursennid are not recommended for use in pregnancy due to genotoxic risks associated with chemically similar compounds. The active metabolite of sennosides is excreted in breast milk, though there are no reports of the laxitive effect in breast fed babies. There is no data on the effects of sennosides on fertility.


Inflammatory bowel disease. Avoid prolonged use.

Food Interaction

  • Avoid natural licorice. Licorice root can induce hypokalemia in patients taking sennosides.

Volume of Distribution

The volume of distribution of radiolabelled intravenous sennoside B in rats was 0.802±0.124L/kg.

Elimination Route


Half Life

The half life of radiolabelled intravenous sennoside B in rats was 8.568±0.651h.


The clearance of radiolabelled intravenous sennoside B in rats was 0.065±0.007L/h/kg.

Elimination Route

3-6% of metabolites are excreted in urine with some in bile. >90% of sennosides are excreted in the feces as polymers with 2-6% of the parent compounds excreted unchanged.

Pregnancy & Breastfeeding use

Pursennid has been assigned to pregnancy category C by the FDA. Animal studies have failed to reveal evidence of teratogenicity. There are no controlled data in human pregnancy. Pursennid should only be given during pregnancy when benefits outweigh risks.

Pursennid is not excreted into human milk. However, Pursennid is a prodrug which is metabolized in vivo to the active sennosides (glucosides of rhein). Rhein is excreted into human milk in very small amounts. No adverse effects have been observed in nursing infants. The American Academy of Pediatrics considers Pursennid to be compatible with breast-feeding.


Nausea or vomiting, undiagnosed abdominal pain, intestinal obstruction.


What is Pursennid used for?

Pursennid used to treat constipation.They work by keeping water in the intestines, which helps to cause movement of the intestines.

How safe is Pursennid?

Pursennid is likely safe for most adults and children over age 2 when taken by mouth, short-term.Pursennid  can cause some side effects including stomach discomfort, cramps, and diarrhea.Pursennid is possibly unsafe when taken by mouth long-term or in high doses.

How does Pursennid work?

Pursennid work by keeping water in the intestines, which helps to cause movement of the intestines.

What are the common side effects of Pursennid?

Common side effects of Pursennid are include:

  • Stomach/abdominal pain or cramping, nausea, diarrhea, or weakness may occur. ...
  • This medication may cause your urine to turn reddish-brown.

How much Pursennid is too much?

Pursennid takes 34.4 mg per day.

Is Pursennid safe during pregnancy?

Pursennid may not be suitable if you're pregnant. Constipation is common at the end of pregnancy . If you're pregnant it is better to ease constipation without taking a medicine.

Is Pursennid safe during breastfeeding?

Usual doses of Pursennid are acceptable to use during breastfeeding.

Can I drink alcohol with Pursennid?

Yes, you can drink alcohol with Pursennid.

When is the best time to take Pursennid?

Pursennid may be best to take this medicine at night or at bedtime.

How quickly do Pursennid work?

Pursennid takes about 8 hours to work. It's best to take Pursennid at bedtime so it works overnight.

How to use Pursennid?

Take Pursennid by mouth as directed by your doctor. If you are self-treating, follow all directions on the product package. If you have any questions, ask your doctor or pharmacist.

Can I take Pursennid for a long time?

Pursennid is possibly unsafe when taken by mouth long-term or in high doses. Don't use Pursennid for more than two weeks.

How often can I take Pursennid?

Pursennid usually not more than 4 tablets two times a day.

Can I take Pursennid everyday?

You shouldn't use it for more than 7 consecutive days unless otherwise directed by your healthcare provider. Long-term Pursennid tea intake may lead to laxative dependence, electrolyte disturbances, and liver damage.

Why do you take Pursennid at night?

Pursennid normally causes a bowel movement within 6 to 12 hours, so it may be taken at bedtime to produce a bowel movement the next day.

Is Pursennid safe for kidneys?

Pursennid tablets or liquid are safe to use if you have kidney disease and you're constipated.

What happen If I missed Pursennid?

If your doctor has directed you to take this medication on a regular schedule and you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Can I overdose on Pursennid?

If someone has overdosed and has serious symptoms such as passing out or trouble breathing call a poison control center right away. Symptoms of overdose may include: severe stomach/abdominal pain or cramping, persistent nausea/vomiting/diarrhea.