1. Drugs Used to Treat Constipation and Diarrhea
Chapter 35
Drugs Used to Treat
Constipation and Diarrhea
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2. Chapter 35
Lesson 35.1
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3. Objectives State the underlying causes of constipation
Explain the meaning of “normal” bowel habits
Cite nine causes of diarrhea
Describe medical conditions in which laxatives should not be used
Identify electrolytes that should be monitored whenever prolonged or severe diarrhea is present
Describe nursing assessments needed to evaluate the patient’s state of hydration when suffering from either constipation or dehydration
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4. Constipation Definition Chronic constipation
Symptom-based disorder of unsatisfactory defecation characterized by infrequent stools, difficult stool passage, or both
Chronic constipation
Symptoms present for at least 3 months
“Normal” bowel habits vary
Daily bowel movement not necessary
As long as patient’s health is good and stool not hardened or impacted, this is acceptable
Occasional constipation is not detrimental to a person’s health, but may cause general discomfort, abdominal fullness, anorexia, or anxiety.
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5. Causes of Constipation
Improper diet
Too little fluid intake
Lack of exercise—sedentary habits
Failure to respond to normal defecation impulses
Muscular weakness of the colon
Diseases such as anemia and hypothyroidism
Frequent use of constipating medicines
Tumors of the bowel or pressure from tumors
Diseases of the rectum
Diets that have too little residue (lacking fruits and vegetables or high in constipating foods) and too little fluid may result in constipation.
Examples of medications causing constipation: morphine, codeine, anticholinergic agents.
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6. Diarrhea Definition Considered a symptom, not a disease
Increase in the frequency or fluid content of bowel movements
Considered a symptom, not a disease
Chronic diarrhea may indicate disease of the stomach or intestine
Complications from severe or prolonged diarrhea
Dehydration, electrolyte depletion, exhaustion
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7. Causes of Diarrhea Intestinal infections Spicy or fatty foods
Enzyme deficiencies
Excessive use of laxatives
Drug therapy
Emotional stress
Hyperthyroidism
Inflammatory bowel disease
Surgical bypass of the intestine
Antibiotics may cause diarrhea because they kill off normal flora in the bowel. Antacids containing magnesium may also cause diarrhea.
Inflammatory bowel diseases include diverticulitis, ulcerative colitis, gastroenteritis, Crohn’s disease.
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8. Treatment of Altered Elimination
Constipation
High-fiber diet, adequate hydration, exercise
Avoid use of laxatives
Avoid laxatives in patients with:
Severe pain or discomfort
Fever, nausea and vomiting
Pre-existing conditions – DM, abdominal surgery
Taking medications that cause constipation
Laxative abusers
Previous use of laxative without success
Prescribed medications that cause constipation: iron, aluminum antacids, antispasmodics, muscle relaxants.
Do not administer laxatives to patients with undiagnosed abdominal pain, or inflammation of the GI tract.
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9. Treatment of Altered Elimination (cont’d)
Diarrhea
Treatment depends on specific cause of diarrhea
Indication of disease of stomach, small or large intestine
Psychogenic
Symptom of cancer of the colon or rectum
Diarrhea can be chronic, mild, or severe.
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10. Nursing Assessment and Health Promotion
Obtain history, medications, activity and exercise, elimination patterns, nutritional history, basic assessment, bowel sounds, vital signs; review laboratory reports
Monitor electrolytes in prolonged diarrhea
Monitor hydration
Promote health
Teach proper handwashing
Teach drug adverse effects
Monitor hydration by evaluating volume of intake, urine output, skin turgor, moisturization of mucous membranes, and daily weight.
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11. Chapter 35
Lesson 35.2
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12. Objectives
Identify the indications for use, method of action, and onset of action for stimulant laxatives, saline laxatives, lubricant or emollient laxatives, bulk-forming laxatives, and fecal softeners.
State the differences between locally acting and systemically acting antidiarrheal agents.
Cite conditions that generally respond favorably to antidiarrheal agents.
Review medications studied to date and prepare a list of those that may cause diarrhea.
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13. Drug Class: Laxatives Actions Stimulant and osmotic laxatives
Subclassified according to action
Stimulant and osmotic laxatives
Action: directly on intestines; cause irritation that promotes peristalsis and evacuation
Osmotic laxatives
Action: hypertonic compounds draw water into the intestines from surrounding tissues, distending bowel and causing peristalsis
Common adverse effects: excessive bowel stimulation, diarrhea.
Serious adverse effects: abdominal tenderness, pain, bleeding, vomiting, diarrhea, increasing abdominal girth.
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14. Stimulant and Osmotic Laxatives
Drugs
Stimulants: bisacodyl (Correctol, Dulcolax, Modane), sennosides A&B (Ex-Lax), senna concentrate (X-Prep)
Osmotics: polyethylene glycol (Colyte, Go-LYTELY, MiraLax), lactulose (Cephulac), glycerin
Actions
Stimulants: cause irritation, promoting peristalsis and evacuation of the bowel
Osmotics: draw water into intestine from surrounding tissues
Uses
Relieve acute constipation
Lactulose and polyethylene glycol are effective in relieving chronic constipation.
Larger doses of polyethylene glycol are routinely used as bowel preparations before radiologic examination of abdominal organs.
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15. Saline Laxatives Drugs
Lubiprostone (Amitiza)
Magnesium citrate (Citrate of Magnesia)
Magnesium hydroxide (Dulcolax Liquid, Phillip’s Milk of Magnesia)
Sodium phosphates (Fleet Phospho-Soda)
Actions: draw water into the intestine from surrounding tissues, distending the bowel, causing peristalsis
Uses: relieve acute constipation
Usually act within 1 to 3 hours and up to 6 hours for sodium phosphates.
Continuous use may alter electrolyte balance and cause dehydration.
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16. Stool Softeners and Bulk-Forming Laxatives
Action: draw water into bowel to soften stools; do not cause peristalsis
Used routinely for prophylactic purposes
Bulk-forming laxatives
Action: cause water to be retained within the stool
Drug of choice for those who use laxatives routinely; they absorb irritating substances and soften stools
For specific drugs, see Table 35-1.
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17. Lubricant Laxatives and Opioid Antagonist
Action: lubricate intestinal wall, allowing for smooth passage of fecal contents
Used as prophylactic for patients who should not strain during defecation
Opioid antagonist
Action: binds to opioid receptors in the GI tract, inhibiting constipation
Used in treatment of opioid-induced constipation
For specific drugs, see Table 35-1.
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18. Drug Class: Antidiarrheal Agents
Actions
Locally acting agents: absorb excess water to cause a formed stool and adsorb irritants or bacteria causing diarrhea
Systemic agents: act through autonomic nervous system to reduce peristalsis and motility of the GI tract, allowing the mucosal lining to absorb nutrients, water, and electrolytes, leaving a formed stool
Uses
Treat sudden-onset diarrhea, inflammatory bowel disease, post-GI surgery
For specific drugs, see Table 35-2.
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19. Drug Class: Antidiarrheal Agents (cont’d)
Therapeutic outcomes
Relief of incapacitation and discomfort of diarrhea
Common adverse effects
Abdominal distension, nausea, constipation
Serious adverse effects
Prolonged or worsened diarrhea
Many OTC antidiarrheal medications are available.
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