A laxative is a drug that promotes bowel movements.
Purpose
Laxatives are used to prevent or treat constipation. They are also used to prepare the bowel for an examination or surgical procedure.
Description
Laxatives work in different ways, by stimulating colon movement, adding bulk to the contents of the colon, or drawing fluid or fat into the intestine. Some laxatives work by combining these functions.
Bisacodyl
Bisacodyl is a non-prescription stimulant laxative. It reduces short-term constipation and is also used to prepare the colon or rectum for an examination or surgical procedure. The drug works by stimulating colon movement (peristalsis); constipation is usually relieved within 15 minutes to one hour after administration of a suppository form and in 6 to 12 hours after taking the drug orally.
Calcium polycarbophil
Calcium polycarbophil is a non-prescription bulk-forming laxative that is used to reduce both constipation and diarrhea. It draws water to the intestine, enlarging the size of the colon and thereby stimulating movement. It reduces diarrhea by taking extra water away from the stool. This drug should relieve constipation in 12 to 24 hours and have maximum effect in three days. Colitis patients should see a reduction in diarrhea within one week.
Docusate calcium/docusate sodium
Docusate, a non-prescription laxative, helps a patient avoid constipation by softening the stool. It works by increasing the penetration of fluids into the stool by
emulsifying feces, water and fat. Docusate prevents constipation and softens bowel movements and fecal impactions. This laxative should relieve constipation within one to three days.
Lactulose
Lactulose, a prescription laxative, reduces constipation and lowers blood ammonia levels. It works by drawing fluid into the intestine, raising the amount of water in the stool, and preventing the colon from absorbing ammonia. It is used to help people who suffer from chronic constipation.
Psyllium
Psyllium is a non-prescription bulk-forming laxative that reduces both constipation and diarrhea. It mixes with water to form a gel-like mass that can be easily passed through the colon. Constipation is relieved in 12 to 24 hours and maximum relief is achieved after several days.
Senna/senokot
Senna/senokot is a non-prescription laxative that reduces constipation by promoting colon movement. It is used to treat bouts of constipation and to prepare the colon for an examination or surgical procedure. This laxative reduces constipation in eight to 10 hours.
Recommended dosage
Laxatives may be taken by mouth or rectally (suppository or enema).
Bisacodyl
Adults or children over 12 years: 5 to 15 mg taken by mouth in morning or afternoon (up to 30 mg for surgical or exam preparation).
Adult (rectal): 10 mg.
Children age 2 to 11 years: 10 mg rectally as single dose.
Children over 3 years: 5 to 10 mg by mouth as single dose.
Children under 2 years: 5 mg rectally as single dose.
Calcium polycarbophil
Adult: 1 g by mouth every day, up to four times a day as needed (not to exceed 6 g by mouth in a 24-hour time period).
Children age 6 to 12 years: 500 mg by mouth twice a day as needed (not to exceed 3 g in a 24-hour time period).
Children age 3 to 6 years: 500 mg twice a day by mouth, as needed (not to exceed 1.5 g in a 24-hour time period).
Children over 12 years (docusate sodium enema): 2 ml.
Children age 6 to 12 years (docusate sodium): 40 to 120 mg by mouth per day.
Children age 3 to 6 years (docusate sodium): 20 to 60 mg by mouth per day.
Children under 3 years (docusate sodium): 10 to 40 mg by mouth every day.
Lactulose
FOR CONSTIPATION:
Adult: 15 to 60 ml by mouth every day.
Children: 7.5 ml by mouth every day.
FOR ENCEPHALOPATHY:
Adult: 20 to 30 g three or four times a day until stools become soft. Retention enema: 30 to 45 ml in 100 ml of fluid.
Infants and children: Parents should follow physician's directions for infants and children with encephalopathy.
Psyllium
Adult: 1 to 2 teaspoons mixed in 8 ounces of water two or three times a day by mouth, followed by 8 ounces water; or one packet in 8 ounces water two or three times a day, followed by 8 ounces of water.
Children over 6 years: 1 teaspoon mixed in 4 ounces of water at bedtime.
Senna/senokot
Adult (Senokot): 1 to 8 tablets taken by mouth per day or 1/2 to 4 teaspoons of granules mixed in water or juice.
Adult (rectal suppository): 1 to 2 at bedtime.
Adult (syrup): 1 to 4 teaspoons at bedtime.
Adult (Black Draught): 3/4 ounce dissolved in 2.5 ounces liquid given between 2 P. M. and 4 P. M. on the day prior to a medical exam or procedure.
Children: Parents should ask their doctor as dosage is based on weight. Black Draught is not to be used by children.
Children age 1 month to 1 year (Senokot): 1.25 to 2.5 ml of syrup at bedtime.
Precautions
The doctor should be informed of any prior allergic drug reaction, especially prior reactions to any laxatives. Pregnancy is also a concern. Animal studies have shown laxatives to have adverse effects on pregnancy, but no human studies regarding pregnancy are currently available. These drugs are only given in pregnancy after the risks to the fetus have been taken under consideration. Nursing mothers should use caution and consult their doctor before receiving these drugs.
Bisacodyl should not be administered to patients with rectal fissures, abdominal pain, nausea, vomiting, appendicitis, abdominal surgery, ulcerated hemorrhoids, acute hepatitis, fecal impaction, or blockage in the biliary tract. Calcium polycarbophil should not be given to anyone with a gastrointestinal blockage (obstruction).
Both psyllium and docusate calcium/docusate sodium should be avoided by patients with intestinal blockage, fecal impaction, or nausea and vomiting. Lactulose should be avoided by patients who are elderly, have diabetes mellitus, eat a low galactose diet, or whose general health is poor.
Finally, senna/senokot is inadvisable for patients with congestive heart failure, gastrointestinal bleeding, intestinal blockage, abdominal pain, nausea and vomiting, appendicitis, or prior abdominal surgery.
Side effects
Laxatives may have side effects. Some, such as nausea and vomiting, are more common than others. Side effects related to specific laxatives are described in this section. With repeated use, people may become dependent on laxatives. All side effects should be reported to a doctor.
Laxatives may interact with other drugs. Sometimes, the laxative can interfere with proper absorption of another drug. A patient must notify their doctor or pharmacist if he or she is already taking any medications so that the proper laxative can be selected or prescribed. Specific drug interactions are:
Bisacodyl: Antacids, H2-blockers, and some herbal remedies (lily of the valley, pheasant's eye, squill).
Senna/senokot: Disulfiram should never be taken with this drug. Also, senna/senokot lowers the absorption of other drugs taken by mouth.
Rhonda Cloos, R.N.
Constipation
—Difficult or infrequent bowel movements.
Diarrhea
—Frequent, watery stools.
Electrolyte levels
—In the bloodstream, electrolyte levels are the amounts of certain acids, bases, and salts. Abnormal levels of certain electrolyes can be life-threatening.
