Chapter 51 - Bowel Disorder Drugs Flashcards
(42 cards)
What is diarrhea?
abnormal passage of stools with increased frequency, fluidity, weight, or with increased stool water excretion acute and chronic
Causes of acute diarrhea
bacterial
viral
drug induced
nutritional factors
protozoa
Causes of chronic diarrhea
tumors
diabetes mellitus
Addison’s disease
Hyperthyroidism
IBS
AIDS
3 types of Antidiarrheals
Adsorbents
Antimotility drugs (anticholinergics and opiates)
Probiotics (AKA, Intestinal flora modifiers, bacterial replacement drugs)
MOA of adsorbents
- coat walls of GI tract
- Bind to the causative bacteria/toxin, then eliminated through stool
Examples of adsorbents
bismuth subsalicylate (Pepto-Bismol)
activated charcoal
aluminum hydroxide
others
MOA of antimotility drugs: anticholinergics
- decreases intestinal muscle tone and peristalsis of GI tract
- Result: slows movement of fecal matter through the GI tract
- used in more severe cases of diarrhea
Example of anticholinergic antimotility drug
belladonna alkaloids (atropine, hyoscyamine)
MOA of opiate antimotility drugs
- decrease bowel motility, relieve rectal spasms
- decrease transit time through bowel -> allows more time for water/electrolyte absorption
- reduce pain by relief of rectal spasms
Examples: paregoric, opium tincture, codeine, loperamide (OTC), diphenoxylate
MOA Antidiarrheals: Intestinal Flora Modifiers
probiotics or bacterial replacement drugs
bacterial cultures of lactobacillus organisms work by:
supplying missing bacteria to the GI tract
suppressing growth of diarhea-causing bactera
example: L. acidophilus (Lactinex)
What are the adverse effects of adsorbent antidiarrheals?
increase bleeding time,
constipation/dark stools,
confusion, twitching,
hearing loss, tinnitus, metallic taste, blue gums
What are the adverse effects of anticholinergic antidiarrheals?
CNS: h/a, dizziness, confusion, anxiety, fatigue, weakness, drowsiness
CV: hypertension, hypotension, dysrhythmias (VTach, VFib, palpitations
GU: urinary retention, hesitancy, impotence
Sense: mydriasis, blurred vision, increase intraocular pressure
Skin: dry skin, flushing
What are the adverse effects of opiate antidiarrheals?
drowsiness, sedation, dizziness, lethargy
nausea, vomiting, anorexia, constipation
respiratory depression
hypotension
urinary retention
flushing
Nursing Implications of antidiarrheals?
Do NOT give bismuth subsalicylate to children/teenagers with chickenpox or influenza because of the risk of Reye’s syndrome
obtain through history of bowel patterns, general state of health, and recent hisotyr of illness or dietary changes, assess for allergies
Use adsorbetns carefully in elderly, and those with increased bleeding time, clotting disorders, recent bowel surgery, confusion
Do not administer anticholinergics to pts with history of narrow-angle glaucoma, GI obstruction, myasthenia gravis, paralytic ileus, and toxic megacolon
What to teach pts for antidiarrheals?
take meds exactly as prescribed, be aware of fluid intake/dietary chagnes
teach pts to notify their physician immediately if symptoms persist
monitor for therapeutic effect
assess fluid volume status, I&O and mucous membranes before, during, and after initiation of treatment
What is constipation?
abnormally infrequent and difficult passage of feces through the lower GI tract
disorder of movement through the colon/rectum
Is constipation a symptom or disease?
Symptom! yay!
Different categories of laxatives?
Bulk-forming
Emollient
Hyperosmotic
Saline
Stimulant
Peripherally acting opioid antagonists
MOA of Bulk-forming laxatives
high fiber
absorb water to increase bulk
distend bowel to initiate reflex bowel activity
examples: psyllium (Metamucil) and methylcellulose (Citrucel)
MOA of emollient laxatives
stool softeners/lubricants
promote more water/fat in stools
lubricate the fecal material/intestinal walls
Examples: stool softeners: docusate salts (Colace, Surfak) lubricants (mineral oil)
MOA of hyperosmotic laxatives
increase fecal water content
results in bowel distention, increased peristalsis, and evacuation
examples: polyethylene glycol (PEG) AKA: GoLytely; sorbitol, glycerin; lactulose (also used to reduce elevated serum ammonia levels)
MOA of saline laxatives
increase osmotic pressure within the intestinal tract, causing more water to enter the intestines
results in bowel distention, increased peristalsis and evacuation
Examples: Magnesium hydroxide (Milk of Mag)
Magnesium citrate (Citroma)
MOA of stimulant laxatives
increased peristalsis via intestinal nerve stimulation
Examples: senna (Senekot) bisacodyl (Dolculax)
Peripherally Acting Opioid Antagonists
treatment of constipation r/t opioid use and bowel resection therapy
block entrance of opioid into bowel
strict regulations for use
allow bowel to function normally with continued opioid use
methylnaltrexone (Relistor)
alvimopan (Entereg)
