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Laxatives
Introduction: Constipation
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is a condition that characterized by infrequent bowel movements that are painful or difficult
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or stools are hard in consistency
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May be accompanied by abdominal pain, back pain and abdominal bloating
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Troublesome to elderly & pregnant female
Patient Definition:
 Hard Stools
 Infrequent stools (<3 per week)
 Excessive straining
 Sense of incomplete bowel emptying
 Excessive, unsuccessful time spent on toilet
Symptoms of chronic constipation
Nausea ( common in eldery)/ vomiting, Abdominal and Rectal pain,
Flatulence
Loss of appetite, Dyspeptic ulcers
Constipation: Causes
Diets low in fibers (vegetable material that is resistant to digestion. It promotes soft stools by adding
bulk to the stool (mechanical)
No enough water
High meat diet
Ignoring the urgeEndocrine disturbances such as DM
Drugs
Narrowing or blockade of the colon by mass or cancer
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Drugs which cause constipation ?????????????????????
Treatment of Constipation
Non-pharmacological Treatment
Plenty Intake of Fluids, Fibers
Examples of foods that are high in fiber content
Vegetables,fruits (include the skin),whole grain breads ,whole grain cereals,prunes ,corn
whole beans (kidney beans),oat bran,barley
Regular Toileting & Exercise
Encourage physical activity , Walking
Pharmacological Treatment
Laxatives
Laxatives: Agents used to relieve constipation or to clear the bowel prior to surgery or examination
Production of a soft formed stool over a period of 1 or more days
Catharsis ‫ – إ‬rapid, fluid evacuation of the bowel, more intense
Indications for laxative use:
No response to adequate dietary and lifestyle advice
Painful anal lesion (piles), episiotomy
To decrease amount of strain under certain conditions (cardiac patients)
Evacuate bowel prior to procedures or examination
To relieve constipation caused by pregnancy and in elderly patients
Increased prevalence of Secondary Causes…..
Immobility - osteoarthritis, advanced cancer
Improper Diet inadequate fiber/fluid
Endocrine & Metabolic Disorders (DM)
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Neurological Disorders, Psychological Conditions , Medications ????????????????
Classification of Laxatives
Bulk-Forming Laxatives
Stool Softeners
Lubricant Laxatives
Stimulant (irritant) Laxatives
Saline Laxatives
Bulk laxatives
They work slowly and stimulate colon naturally. They are considered the safest type of laxative and the
only type that might be recommended for daily use.
They form a bulky hydrated mass in the gut lumen promoting peristalsis and improving fecal
consistency.
They may take several days to work but have no serious unwanted effects.
Bulk laxatives
The bulk laxatives include psyllium (Metamucil), polycarbophil (FiberCon), and methylcellulose (Citrucel),
wheat barn
These agents are not broken down by the normal processes of digestion in the upper GIT.
Bulk laxatives
They should be taken with plenty of water
Bulk-producing agents have the gentlest of effects among laxatives and can be taken just for maintaining
regular bowel movements
Available as powders and are mixed with fluids. Fruit juice, and soft drinks mask the gritty taste
‫ رملي‬of these laxatives better than water
Side effects: Abdominal distension & flatulence
Contraindications: Intestinal obstruction
Stimulant / Irritant Laxatives
Examples: Bisacodyl, castor oil, senna
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Stimulant laxatives are the harshest laxatives. They stimulates intestinal motility causing the bowel to
squeeze or contract to move the stools out
may be given by mouth or suppository
Stimulant Laxatives :Side effects
Abdominal discomfort, cramping, and tenesmus often occur acutely
Chronic, long-term use of stimulant laxatives can lead to loss of colon function (cathartic colon)
Consequently, constipation becomes increasingly worse and unresponsive to laxatives
Castor oil
It is a liquid stimulant laxative that works in the small intestine.
Recinoleic acid is the active m. not the oil
Castor oil: is used to clean the colon before surgical and diagnostic procedures (colonoscopy).
It promotes evacuation of the bowels usually within 2 to 6 hours. ( watery stools)
Castor oil: side effects
It has an unpleasant taste (take juice or other flavored liquids to hide its taste)
Abdominal discomfort, cramping, and tenesmus often occur
The absorption of nutrients & minerals by the small intestine can be impaired by the frequent use of
castor oil
Fecal Softeners (Emollient laxatives)
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Example of fecal softeners is docusate sodium
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Mechanism of action: they soften stools by causing water and fats to penetrate the stool,
making it easier to move along the GIT
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They are used more to prevent constipation than to treat it
Stool Softener: indications
Stool softeners are commonly recommended for patients who should avoid straining while
defecating, including:
 Patients recovering from abdominal, pelvic, or rectal surgery, childbirth
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 Patients with painful piles or anal fissures
 Softening the stool in these patients can help reduce pain during defecation
Lubricant Laxatives
Examples: Glycerin Suppositories, mineral oil (Liquid paraffin)
Lubricant laxatives work by coating the surface of the stool make it slippery so move out of the body
more easily
Liquid paraffin now seldom used may decrease the absorption of fat-soluble vitamins (A, D, E and K),
it is now seldom used
Glycerin Suppositories lubricate the inside of the anus
Saline Laxatives
 Non-absorbable salts: magnesium salts like Mg sulfate, Mg hydroxide
 Milk of Magnesia
 These agents trap increased volumes of fluid in the lumen of the bowel, accelerating the
transfer of the gut contents through the small intestine
 Distension, abdominal cramps lead to rapid effect within about an hour
Saline Laxatives
 The amount of magnesium absorbed after an oral dose is usually too small to have adverse
systemic effects
 Therapeutic uses: bowel evacuation prior to surgical procedures
Saline Laxatives: Side effects
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Magnesium salts should not be used for prolonged periods in patients with renal insufficiency
for fear of hypermagnesemia (cardiac depression, neuromuscular disorders and CNS
depression)
Dehydration and electrolyte disturbances
Lactulose
 Lactulose is a semisynthetic disaccharide of fructose and galactose.
 It is poorly absorbed and produces an effect similar to that of the other osmotic laxatives. It
takes 2-3 days to act
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 Unwanted effects: with high doses flatulence, cramps, diarrhea and electrolyte disturbance.
Suppositories
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Rapid onset of action
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Suppositories in general establish reflex defecation
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Different types of suppositories have different mechanism of action:
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Stimulant suppositories (bisacodyl)
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Lubricant Suppositories (glycerin)
Enemas
Mechanism of action:
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Distending the rectum to contract & eliminate stools
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Defecation usually occurs between a few minutes & one hour after the enema is
inserted
Enemas
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Indication:
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Preparation of the colon before surgical or endoscopic, procedures
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Occasional rather than regular use
Side effects:
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Frequent enemas → fluid & electrolyte disturbances
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Soapsuds enemas are not recommended
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Injury by the nozzle
Contraindications of Laxatives
Inflammatory bowel diseases
Acute surgical abdomen
Chronic use and abuse
( damage the rectum).