What is Constipation?• Passage of hard, dry bowel movements,usually fewer than three times a week• Symptoms:– painful bowel movements– bloated– uncomfortable– sluggish
• As a rule, if more than three dayspass without a bowel movement,the intestinal contents may harden,and a person may have difficulty oreven pain during elimination.Straining during bowel movementsor the feeling ofincomplete evacuation may also bereported as constipation
What are Some Common MisconceptionsAbout Constipation?• that a bowel movement every day isnecessary.• that wastes stored in the body areabsorbed and are dangerous to healthor shorten the life span.These misconceptions have led to amarked overuse and abuse of laxatives.
Is Constipation Serious?• it may signal and be the only noticeablesymptom of a serious underlyingdisorder such as cancer.Complications• Hemorrhoids• Fissures
Laxatives/cathartics/PurgativeLaxatives:• promote a soft stoolCathartics• Results in a soft to watery stool withsome crampingPurgative:• is a harsh cathartic causing a waterystool with abdominal cramping
MOA• Absorb water into the intestineincreasing fecal bulk andperistalsis• Dissolve or swell in the intestines------- stimulate peristalsis
• Onset of action: 8-24 hours• Peak action: 3 days
The benefits of bulk-forming laxatives arenot absorbed from the intestines intothe body safe for long-term use.• safe for elderly patients.• Helpful in patients with irritable bowelsyndrome, diverticulosis, andcolostomies.
• Should be mixed in a glass of water orjuice, stirred and drunk immediatelyfollowed by a half to a full glass ofwater.• Why with water or juice?Because• Insufficient fluid intake cause the drugto solidify in GI tract results inintestinal obstructionPrecaution
Precautions for using bulk-forminglaxatives.----- may not be appropriate for patients whomust restrict oral fluid intake (such aspatients with kidney failure).• Patients with narrowing of the digestive tract(including esophageal stricture, intestinalstricture, or severe adhesions)• ----- risk of blockage of the intestine or theesophagus.
MOAHyperosmolar salts or saline products :insoluble, remain in lumen pull water into colonand increase water in the feces to increase bulk –increase peristalsisLactulose:• draws water into intestine and promotes water andelectrolytes retention• Decreases serum ammonia levelGlycerin• acts like Lactulose increases water in the feces inlarge intestine
MOA• Increasing water and electrolytesecretion by the mucosa• By increasing peristalsis ---- bystimulating sensory nerveendings in GI mucosa
• The feces are movedthrough the bowel toorapidly to allow colonicabsorption of fecal waterso a watery stool iseliminated
Bisacodyl (Dulcolax)• Can be given: orally ,suppository or enema.Onset of action• Oral form : 6 to 10 hours.• Suppository: 15 to 30 min
Senna,Cascarasagrada, Aloe• Drug passes unchanged into the colon• laxatives into activecompounds (anthracene derivative emodin).• The active compounds then absorb and have adirect stimulant effect on myenteric plexus ----------------------------- contraction of colon muscles.• Onset of action: 6 to 8 hours.bacteria
Castor oilIs hydrolyzed in upper smallintestine to ricinoleic acid aLocal irritant that increasesIntestinal motility• Onset of action: usuallywithin 2 to 6 hours.
Therapeutic UseCleansing the colon forcolonoscopies, bariumenemas, and intestinalsurgeries.
Side effects• Phenophthalein: Nausea, abdominal cramps,weakness, reddish brown urine)• Bisacodyl: Fluid and electrolyte imbalance(Potassium and calcium)Mild cramping, and diarrheaCastor oil: stimulates uterine contraction ----spontaneous abortionSenna: damage nerves--- loss of intestinalmuscular tone
Precaution• Chronic, long-term use ofstimulant laxatives can lead to:• loss of colon function (catharticcolon).• Consequently, constipationbecomes increasingly worse andunresponsive to laxatives.
Stool Softeners (Emollient laxatives)• The active ingredient inmost stool softeners is amedicine called docusate.
MOA• prevent hardening of the feces byadding moisture to the stool.• Become emulsified with stool.• They decrease surface tension ofthe fecal mass to allow water topenetrate into the stool.•
Therapeutic use• Used to prevent constipation• commonly recommended for patients whoshould avoid straining while defecating,including:Patients who are recovering from abdominal, pelvic, or rectal surgery, childbirth, or a heart attack; persons with severe high blood pressure orabdominal hernias; and patients with painful hemorrhoids and/or analfissures.
Mineral oil• Lubricant laxative• coats and softens stool• Soften stool by retarding colonicabsorption of fecal water• Exact mechanism is unknown
Therapeutic use• Used by patients who need toavoid straining hernia repair, hemorrhoid surgery, heart attacks, and childbirth.
Precautions for using lubricant laxatives• Mineral oil should be avoided in patients takingblood thinners, such as Coumadin.• Mineral oil decreases the absorption of vitamin K(important in forming clotting factors in the blood)from the intestines.• Mineral oil should not be taken during pregnancysince it may inhibit vitamin absorption anddecrease the availability of vitamin K to the fetus.• Mineral oil can cause pneumonia if it leaks into thelungs.
Therapeutic Uses• to relieve constipation and rectal fecalimpaction(blockage of the rectum by hard,compacted stool).• in conjunction with oral laxatives incleansing the colon in preparation forbarium enema studies.
Examples of enemas andsuppositories• Microenema, which containsdocusate,• Ducolax Suppository, whichcontains bisacodyl,• Kleen Enema, which containssodium biphosphate.