Exam 4-5 Bowel Disorder Drugs Flashcards
Diarrhea
Abnormal passage of feces with increased frequency, fluidity, and weight, or with increased feces water excretion
Acute diarrhea
- Sudden onset in a previously health person
- Lasts from 3 days to 2 weeks
- Self-limiting
- Resolves without sequelae
Chronic diarrhea
- Lasts for more than 3 weeks
- Associated with recurring passage of diarrheal feces, fever, loss of appetite, nausea, vomiting, weight loss, and chronic weakness
Causes of acute diarrhea
*Bacterial, viral, drug induced, nutritional factors, protozoa
Causes of chronic diarrhea
*tumors, diabetes mellitus, Addison’s disease, Hyperthyroidism, Irritable bowel syndrome, AIDS
Antidiarrheals: Mechanism of Action
Adsorbents: Coat the walls of the GI tract
Bind to the causative bacteria or toxin, which is then eliminated through the feces
Examples: bismuth, subsalicylate (Pepto-Bismol), kaolin-pectin, activated charcoal, attapulgite
Antidiarrheals: Mechanism of Action/Amtimotility drugs: anticholinergics
- Decreased intestinal muscle tone and peristalsis of GI tract
- Result: slowing the movement of fecal matter through the GI tract
- Examples: belladonna alkaloids, atropine, hyoscyamine
Antidiarrheals: Mechanism of Action Antimotility drugs: Opioids
- Decrease intestinal motility and relieve rectal spasms
- Slow transit through the intestines, allowing more time for water and electrolyte to be absorbed
- Reduce pain by relief of rectal spasms
- examples: paregoric, opium tincture, codeine, loperamide (OTC), diphenoxylate
Antidiarrheals: Mechanism of Action: Intestinal flora modifiers
- Probiotics or bacterial replacement drugs
- Bacteria cultures of Lactobacillus organisms work by:
- supplying missing bacteria to the GI tract
- suppressing the growth of diarrhea-causing bacteria
- Example: L acidophilus (Lactinex)
Antidiarrheals: Comibination Products
Diphenoxylate and atropine
- Diphenoxylate is combined with subtherapeutic amounts of atropine
- This discourages recreational opioid use
- Large dosages will result in extreme anticholinergic effects (dry mouth, abdominal pain, tachycardia, blurred vision)
Antidiarrheals: Adverse Effects: Adsorbents
- Increased bleeding time
- Constipation, dark feces
- Confusion, twitching
- Hearing loss, tinnitus, metallic taste, blue gums
Antidiarrheals: Adverse Effects: Anticholinergics
- Urinary retention, hesitancy, impotence
- Headache, dizziness, confusion, anxiety, drowsiness
- Dry skin, rash, flushing
- Blurred vision, photophobia, increased intraocular pressure
- Hypotension, hypertension, bradycardia, tachycardia
Antidiarrheals: Adverse Effects
Opioids
- drowsiness, sedation, dizziness, lethargy
- Nausea, vomiting, anorexia, constipation
- Respiratory depression
- Hypotension
- Urinary retention
- flushing
Constipation
- Abnormally infrequent and difficult passage of feces through the lower GI tract
- Symptom, not a disease
- Disorder of movement through the colon and/or rectum
- Can be caused by a variety of diseases or drugs
Laxatives
- bulk forming
- emollient
- hyperosmotic
- saline
- stimulant
- peripherally acting opioid antagonists
Laxatives: Mechanism of Action: Bulk forming
*High fiber
*Absorb water to increase bulk
*Distend intestines to initiate reflex intestinal activity
Examples: phyllium (Metamucil)
methylcellulose (Citrucel)
Laxatives: Mechanism of Action: Emollient
*Stool softners and lubricants
*Promote more water and fat in the feces
*Lubricate the fecal material and intestinal walls
Examples: Fecal softeners: docusate salts (Colace, Surfak)
*Lubricants: mineral oil
Laxatives: Mechanism of Action: Hyperosmotic
*Increase fecal water content
*Result: bowel distention, increased peristalsis, and evacuation
Examples:
-polyethylene glycol (GoLTELY)
-sorbitol, glycerin
-lactulose (also used to reduce elevated serum ammonia levels)
Laxatives: Mechanism of Action: Saline
*Increase osmotic pressure within the intestinal tract, causing more water to enter the intestines
*Result: intestinal distention, increased peristalsis, and evacuation
Examples
-Magnesium hydroxide (Milk of Magnesia)
-Magnesium citrate (Citroma)
Laxatives: Mechanism of Action: Stimulant
*Increases peristalsis via intestinal nerve stimulation
Examples-
-senna (Senekot)
-bisacodyl (Dulcolax)
Peripherally Acting Opioid: Antagonists
- Treatment of constipation related to opioid use and bowel resection therapy
- Allow bowel to function normally with continued opioid use
- methylnaltrexone (Relistor)
- alvimopan (Entereg)
Laxatives: Indications: Bulk forming
Use/ acute and chronic constipation
Irritable bowel syndrome
Diverticulosis
Laxatives: Indications: Emollient
Use/acute and chronic constipation
Softening of fecal impaction, facilitation of BMs in anorectal conditions
Laxatives: Indications: Hyperosmotic
Use/Chronic constipation
Diagnostic and surgical preps
Laxatives: Indications: Saline
Use/Constipation
Diagnostic and surgical preps
Laxatives: Indications: Stimulant
Use/Acute constipation
Diagnostic and surgical preps
Laxatives: Adverse Effects: Bulk forming
- Impaction
- Fluid overload
- Electrolyte imbalances
- Esophageal blockage
Laxatives: Adverse Effects: Emollient
- Skin rashes
- Decreased absorption of vitamins
- Electrolyte imbalances
Laxatives: Adverse Effects: Hyperosmotic
- Abdominal bloating
- Electrolyte imbalances
- Rectal irritation
Laxatives: Adverse Effects: Saline
- Magnesium toxicity (with renal insufficiency)
- Cramping
- Electrolyte imbalances
- Diarrhea
- Increased thirst
Laxatives: Adverse Effects: Stimulant
- Nutrient malabsorption
- Skin rashes
- Gastric irritation
- Electrolyte imbalances
- Discolored urine
- Rectal irriation
All laxatives can cause
electrolyte imbalances
