Laxative and Anti-Diarrhea Flashcards
What does constipation mean?
A change in bowel habits but has a varied meaning
What are bulk laxatives?
Oral non-digestible hydrophilic colloids that absorb water
What do bulk laxatives cause?
Intestinal distension that promotes peristalsis
What are examples of bulk laxatives?
Psyllium seed
Methylcellulose
How do stool softeners work?
Surfactants that promote water absorption in stool
Examples or stool softeners?
Mineral oil
Docusate
Three general categories for osmotic laxatives:
Magnesium or phosphate salts
Non-absorbable sugars
Polyethylene glycols
What are non-absorbable sugars?
Lactulose
Sorbitol
Polyethylene glycol molecular weight?
3350
What are stimulant laxatives?
Aloe
Senna
Cascara sagrada
Bisacodyl
What is a common chloride channel activator?
Lubiprostone
How do guanylate cyclase C agonists work?
Stimulate guanylate cyclase 2C increasing bicarbonate and Cl- secretion by CFTR
What effect do guanylate cyclase c agonists have of neurons?
Decrease activation of colonic sensory neurons (decreases pain) and activates colonic motor neurons (increasing smooth muscle contraction)
Who do you give narcotic receptor antagonists to?
Patients on narcotic therapy
What are three narcotic receptor therapies and which are chronic and acute therapy?
Chronic: Methylnaltrexone, naloxegol
Acute: Alvimopan
What are bile acid binders used for?
Regional ileitis - Crohn’s disease
How do bile acid binders work?
They bind and prevent reabsorption of bile acids in the lumen
Example of bile acid binder:
Cholestyramine
What does bismuth subsalicylate do?
Binds and inactivates bacterial enterotoxins
What is octreotide?
An analog of somatostatin (works as somatostatin inhibiting everything)
What are two drugs that are antidiarrheal opioids?
Diphernoxylate
Loperamide
Why is loperamide OTC?
Because it fails to reach significant CNS levels
What is used to reverse opiate induced constipation?
Alvimopan (short term)
Methylnaltrexone (caution with intestinal malignancy)
Naloxegol (cancer)
What are the three classifications of primary constipation?
Normal transit: hard stool or difficult defecation with normal frequency
Slow transit: abnormal innervation of bowels with slow infrequent defecation
Defecation disorders: cannot relax muscles for defecation or stretch response diminished (older ppl)
What causes secondary constipation?
Medication, chronic disease, psychosocial
What is biofeedback used for?
To retrain the defecation muscles
What are enemas and suppositories good for?
Fecal impactions or patients that cannot tolerate oral preparations
Why are phosphate enemas avoided in older patients?
It can mess with electrolyte balance and become fatal
