What is Senna?
Senna (senokot) is an FDA-approved nonprescription laxative. It is used to treat constipation and also to clear the bowel before diagnostic tests such as colonoscopy. Senna is also used for irritable bowel syndrome (IBS), hemorrhoids, and weight loss.
Senna fruit seems to be gentler than senna leaf. This has led the American Herbal Products Association (AHPA) to warn against long-term use of senna leaf, but not senna fruit. The AHPA recommends that senna leaf products 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.”
How does it work?
Senna contains many chemicals called sennosides. Sennosides irritate the lining of the bowel, which causes a laxative effect. Senna is in a class of medications called stimulant laxatives. It works by increasing activity of the intestines to cause a bowel movement.
How should Senna be used?
Senna comes as a liquid, powder, granules, chewable pieces, and tablets to take by mouth. It may be taken once or twice daily. Senna 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. Do not take senna for more than 1 week without talking to your doctor.
Follow the directions on your package or prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take senna exactly as directed. Frequent or continued use of senna may make you dependent on laxatives and cause your bowels to lose their normal activity. If you do not have a regular bowel movement after taking senna, do not take any more medication and talk to your doctor.
If you are taking certain senna products (Ex-Lax® regular ormaximum strength tablets or Perdiem Overnight Relief), swallow the pills whole with a glass of water; do not split, chew, or crush them.
Why take senna at night?
Doctors generally recommend that you take senna at bedtime so it works overnight. Senna takes about 8 hours to work so that by the time you wake up in the morning you can easily empty your bowel.
Senna is generally well tolerated and thought to be safe for most people. However, it does have the potential to cause serious complications in some people with certain health conditions and who take certain medications.
Is it OK to take senna in the morning?
Taking senna in the morning is a bad idea because senna can trigger bowel movement within 6 to 12 hours. This has the potential to disrupt your day. It is better to take this medicine at night or at bedtime. You can take it either before the evening meal to produce results the next morning.
What are the side effects of senna?
Senna can cause some uncomfortable and even some serious side effects.
They can include:
- fluid loss
- abdominal pain
- electrolyte disturbances
- feeling faint
Long-term use of senna can cause dependence in order to have a bowel movement, finger clubbing (usually reversible), rectal bleeding, and wasting.
Someone experiencing any of these side effects should speak with their doctor, especially if they do not go away.
It is essential to drink plenty of fluids or electrolyte replacement solutions, such as Gatorade, when taking senna. This is to prevent a person from losing too much fluid or electrolytes, especially if they have diarrhea.
What are the drug interactions?
There are several drug interactions to be noted. By being aware of these, people can make sure that they are drinking senna tea safely.
People taking the following medications or herbal supplements should avoid taking senna:
Those already taking the herb horsetail should not drink senna tea as both are believed to lower potassium levels.
- Contraceptives: Senna can interact with the form of estrogen in some contraceptives, including the vaginal ring, patch or pills. It might make the birth control less effective, making it more likely for an accidental pregnancy to occur.
- Digoxin: Senna can cause electrolyte imbalances in the body, especially in potassium levels. Low potassium can cause problems for someone taking digoxin.
- Warfarin: Diarrhea in people taking warfarin can increase the risk of serious bleeding. Because senna can cause diarrhea, anyone taking warfarin should avoid using senna.
- Diuretics: Like senna, some diuretics can also decrease potassium and other electrolyte levels. Taking these two medications together can cause potassium levels to drop to a dangerous level.
- Estrogens: Estrogens in hormone replacement therapies react the same way as birth control pills. Using senna with hormone replacement therapy may mean that the estrogen is not absorbed or work as well.
- Horsetail: Horsetail is an herb that some people take for several different reasons. There is some thought that horsetail could lower potassium levels in some people. Taking senna with horsetail may lower potassium levels too much.
- Licorice: Licorice also lowers potassium levels; people should avoid taking both licorice and senna together.