Report on Senna Side Effects and Usage


Natural health supplements sometimes have unexpected side effects or interactions with medication that can lead to adverse reactions that are sometimes life threatening. The following is a list of cautions that you should be aware of before using senna (Cassia angustifolia). These are referred to as drug/herb interactions.

Warning 1 – Contraindications: Senna should not be used by people with potassium deficiency, diverticular disease, ulcerative colitis, Crohn’s disease, severe hemorrhoids, blood vessel disease, gastrointestinal cancer, congestive heart failure, heart disease, liver disease, anal prolapse, severe anemia, abdominal hernia, appendicitis, recent colon surgery, kidney disease, stomach inflammation, or hemorrhoids.

Warning 2 – Cardiac glycosides: Chronic use of senna may potentiate cardiac glycosides.

Warning 3 – Diuretic drugs: Using senna together with “water pills” may decrease the potassium level in the body too much. Some of the diuretics or “water pills” that can decrease potassium include hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), chlorothiazide (Diuril), furosemide (Lasix), chlorthalidone (Thalitone), and others.

Warning 4 – Disulfiram: Experts recommend avoiding concurrent use.

Warning 5 – Digoxin (Lanoxin): Senna is a stimulant laxative, which can decrease potassium levels in the body and increase the risk of side effects of digoxin.

Warning 6 – Warfarin (Coumadin): The diarrhea caused by senna can increase the effects of warfarin and increase the risk of bleeding. If you take warfarin talk to your doctor about the amount of senna it would be safe to use.

Warning 7 – Calcium Channel Blockers: Using senna with calcium channel blockers causes potassium depletion. Experts recommend avoiding concurrent use.

Used as a natural health remedy: senna is used internally for the following benefits and conditions:

  • Laxative to treat constipation (FDA approved use)
  • Colonoscopy: Senna may be used to clear the bowel before this diagnostic test.
  • Colon cleanse
  • Irritable bowel syndrome (IBS)
  • Diet aid to lose weight

The American Herbal Products Association (AHPA) has issued a warning against long-term use of senna leaf. This warning does not apply to senna fruit. The AHPA recommends that products made with senna leaf be labeled, “Do not use this product if you have abdominal pain or diarrhea. Consult a healthcare provider prior to use if you are pregnant or nursing. Discontinue use in the event of diarrhea or watery stools. Do not exceed recommended dose. Not for long-term use.”

Not for long-term use: Using senna for longer than 10 days can cause the bowels to stop functioning normally and might cause a dependence on this herb as a laxative. Long-term use can also change the electrolyte balance of the blood, which can cause liver damage, heart function disorders, muscle weakness, and other harmful effects.

Long term use, which is abuse, may cause electrolyte imbalance (loss of potassium), excessive loss of body fluids, nausea, rash, swelling of the fingertips, weight loss, and a dark pigmentation in the colon, called melanosis coli. Discontinue using senna immediately if you experience these side effects.

In one double blind trial senna was more effective as a preparatory agent for bowel surgery than the commonly used polyethylene glycol (PEG). Patients who were scheduled to undergo bowel surgery received either senna or PEG the night before surgery. Surgeons rated the efficacy of senna at clearing the bowels at 70%, compared to 58% efficacy for PEG. The surgeon should aways supervise using senna for this purpose.

Although small amounts of senna are known to pass through breast milk, it doesn’t seem to be a problem for nursing babies. As long as the mother uses senna in recommended amounts, it does not cause changes in the frequency or consistency of babies’ stools.

Side Effects of Senna

The known side effects of using senna include:

  1. Abdominal cramps/pain
  2. Diarrhea
  3. Discolored urine
  4. Stomach discomfort

Other side effects may also occur when using senna. (See form below)

Overdose: Senna has been linked to liver toxicity. There is a report of a 52-year-old woman who ingested one liter of senna tea per day for over 3 years. She developed acute liver failure and kidney impairment requiring intensive care therapy.

Senna can be found as capsules, tablets, liquid extracts, and dried root. Senna is also known as aden senna, Cassia senna, cassia acutifolia, cassia marilandica, cassia augustifolia, wild senna, and locust plant.

An adverse reaction is possible with this herb, which may result in a thrush flare-up.

As with any herb, a serious allergic reaction is possible. Seek immediate medical attention if you notice any symptoms of a serious allergic reaction. These may include a rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.

Return to the Herb List.

For questions and answers about the side effects of herbs see the Herb Forum

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