Drug Therapy for Constipation - Wolters Kluwer PDF Notes

Chapter 39 Drug Therapy for Constipation and Elimination Problems  Diet and lifestyle, particularly decreased Risk Factors for levels of physical activity Constipation Female gender Nonwhite status Advanced age...

Chapter 39 Drug Therapy for Constipation and Elimination Problems  Diet and lifestyle, particularly decreased Risk Factors for levels of physical activity Constipation Female gender Nonwhite status Advanced age Low levels of education and income Copyright © 2025 Wolters Kluwer. All rights reserved. 2  The cerebral cortex normally controls the Constipation #1 defecation reflex so that defecation can occur at acceptable times and places. Voluntary control inhibits the external anal sphincter to allow defecation or contracts the sphincter to prevent defecation. When the external sphincter remains contracted, the defecation reflex dissipates, and the urge to defecate usually does not recur until additional feces enter the rectum or several hours later. Copyright © 2025 Wolters Kluwer. All rights reserved. 3  In people who often inhibit the defecation Constipation #2 reflex or fail to respond to the urge to defecate, constipation develops as the reflex weakens. oConstipation is a symptom, not a disease. oInfrequent and painful expulsion of hard, dry stools Difficult to define clearly (no “normal” number of stools); traditional medical definition includes three or fewer bowel movements per week oRome III criteria (multisymptom checklist) Copyright © 2025 Wolters Kluwer. All rights reserved. 4  Is the following statement True or False? Question #1 The traditional medical definition of constipation includes three or fewer bowel movements per day. Copyright © 2025 Wolters Kluwer. All rights reserved. 5  False Answer to Question #1 Rationale: The traditional medical definition of constipation includes three or fewer bowel movements per week. Copyright © 2025 Wolters Kluwer. All rights reserved. 6  Understand the importance of diet, exercise, Nonpharmacologi and fluid intake in promoting normal bowel c Measures to function and preventing constipation. Prevent or Treat Increase activity and exercise. Constipation Increase intake of dietary fiber (e.g., vegetables, fruits, cereal grains). Drink at least 6 to 10 glasses (8 ounces each) of fluid daily, if not contraindicated. Establish and maintain a routine for bowel elimination (e.g., going to the bathroom immediately after breakfast). Copyright © 2025 Wolters Kluwer. All rights reserved. 7  Is the following statement True or False? Question #2 Drink at least 6 to 10 glasses (8 ounces each) of fluid daily to assist in prevention of constipation. Copyright © 2025 Wolters Kluwer. All rights reserved. 8  True Answer to Question #2 Rationale: Drink at least 6 to 10 glasses (8 ounces each) of fluid daily to assist in prevention of constipation. Copyright © 2025 Wolters Kluwer. All rights reserved. 9  Bulk-forming laxatives (prototype: psyllium) Laxatives add mass to the feces, stimulating peristalsis and defecation. They must be taken with water to avoid obstruction. Generally, bulk- forming drugs are the most desirable laxative for long-term use. Lubricant laxatives (mineral oil) lubricate the fecal mass and slow colonic absorption of water from the fecal mass. It may interfere with the absorption of fat-soluble vitamins and if aspirated may result in a lipid aspiration pneumonia. Surfactant laxatives (e.g., docusate calcium, docusate sodium) decrease the surface tension of the fecal mass to allow water and fat to penetrate into the stool, making it softer Copyright © 2025 Wolters Kluwer. All rights reserved. 10 and easier to expel. They have little true  Stimulant cathartics (prototype: bisacodyl) are Cathartics the strongest and most abused laxative products. They irritate the GI mucosa, pull water into the intestinal lumen, and stimulate peristalsis. They produce a watery stool and may lead to fluid, electrolyte, and acid–base imbalances. Saline cathartics (e.g., magnesium citrate, milk of magnesia) increase the osmotic pressure in the intestinal lumen, resulting in the retention of water, which distends the bowel and stimulates peristalsis. They produce a semifluid stool and may lead to fluid and electrolyte imbalances. Copyright © 2025 Wolters Kluwer. All rights reserved. 11  To relieve constipation in patients who are Indications for pregnant, older adult patients whose Use #1 abdominal and perineal muscles have become weak and atrophied, children with megacolon, and patients receiving drugs that decrease intestinal motility (e.g., opioid analgesics, drugs with anticholinergic effects) To prevent straining at stool in patients with coronary artery disease (e.g., postmyocardial infarction), hypertension, cerebrovascular disease, and hemorrhoids and other rectal conditions Copyright © 2025 Wolters Kluwer. All rights reserved. 12  To empty the bowel in preparation for bowel Indications for surgery or diagnostic procedures (e.g., Use #2 colonoscopy, barium enema) To accelerate elimination of potentially toxic substances from the GI tract (e.g., orally ingested drugs or toxic compounds) To prevent absorption of intestinal ammonia in patients with hepatic encephalopathy Copyright © 2025 Wolters Kluwer. All rights reserved. 13  To obtain a stool specimen for parasitologic Indications for examination Use #3 To accelerate excretion of parasites after anthelmintic drugs have been administered To reduce serum cholesterol levels (psyllium products) Copyright © 2025 Wolters Kluwer. All rights reserved. 14  Psyllium or any fiber product may result in Adverse Effects severe flatulence (gas) and bloating. There have been reports of abdominal cramping and esophageal or bowel obstruction. Common adverse effects of bisacodyl include abdominal pain and cramping, nausea, diarrhea, and weakness. Copyright © 2025 Wolters Kluwer. All rights reserved. 15  Lactulose exerts an osmotic effect, pulling Miscellaneous water into the intestinal lumen and Agents for stimulating peristalsis. It is also useful in Constipation treating hepatic encephalopathy by decreasing the production of the waste product ammonia. Sorbitol is often given with sodium polystyrene sulfonate (Kayexalate) in the treatment of hyperkalemia to aid in the expulsion of the potassium–resin complex. Lubiprostone aids in treating chronic idiopathic constipation in adults by increasing intestinal fluid secretion, stimulating intestinal motility and defecation. Copyright © 2025 Wolters Kluwer. All rights reserved. 16  Is the following statement True or False? Question #3 Sorbitol exerts an osmotic effect, pulling water into the colon and stimulating peristalsis. It is also useful in treating hepatic encephalopathy by decreasing the production of the waste product ammonia. Copyright © 2025 Wolters Kluwer. All rights reserved. 17  False Answer to Question #3 Rationale: Lactulose exerts an osmotic effect, pulling water into the colon and stimulating peristalsis. It is also useful in treating hepatic encephalopathy by decreasing the production of the waste product ammonia. Sorbitol is often given with sodium polystyrene sulfonate in the treatment of hyperkalemia to aid in the expulsion of the potassium–resin complex. Copyright © 2025 Wolters Kluwer. All rights reserved. 18  Assess patients for current or potential Assessment #1 constipation. oSigns and symptoms, which include the following: Decreased number and frequency of stools Passage of dry, hard stools Abdominal distention and discomfort Flatulence (expulsion of gas through the rectum) Copyright © 2025 Wolters Kluwer. All rights reserved. 19  Presence of risk factors Assessment #2 oDiet with minimal fiber (e.g., small amounts of fruits, vegetables, and whole-grain products) oLow fluid intake (e.g., less than 6 to 10 glasses [8 ounces each] daily) oImmobility or limited activity Copyright © 2025 Wolters Kluwer. All rights reserved. 20  Use of drugs that reduce intestinal function Assessment #3 and motility (e.g., opioid analgesics, antacids containing aluminum or calcium, anticholinergics, calcium channel blockers, clozapine, diuretics, iron, phenothiazines, cholestyramine, colestipol, sucralfate, tricyclic antidepressants, vincristine) Overuse of antidiarrheal agents, which also may cause constipation Copyright © 2025 Wolters Kluwer. All rights reserved. 21  Conditions that may reduce intestinal function Assessment #4 and motility (e.g., depression, eating disorders such as anorexia nervosa, hypothyroidism, hypercalcemia, multiple sclerosis, Parkinson disease, spinal lesions) Hemorrhoids, anal fissures, or other conditions characterized by painful bowel elimination Older adult or debilitated status Copyright © 2025 Wolters Kluwer. All rights reserved. 22  Assist patients with constipation and Implementation caregivers to #1 oUnderstand the importance of diet, exercise, and fluid intake in promoting normal bowel function and preventing constipation oIncrease activity and exercise oIncrease intake of dietary fiber (e.g., vegetables, fruits, cereal grains) Copyright © 2025 Wolters Kluwer. All rights reserved. 23  Drink at least 6 to 10 glasses (8 ounces each) Implementation of fluid daily, if not contraindicated. #2 Establish and maintain a routine for bowel elimination (e.g., going to the bathroom immediately after breakfast). Understand and comply with drug therapy. Copyright © 2025 Wolters Kluwer. All rights reserved. 24  Monitor patient responses. Implementation oRecord number, amount, and type of bowel #3 movements. oRecord vital signs. Hypotension and weak pulse may indicate deficient fluid volume. Copyright © 2025 Wolters Kluwer. All rights reserved. 25