GI Motility 2 Flashcards
Which laxative?
- rapid movement of water into the distal small bowel and colon leads to a high volume of liquid stool followed by rapid relief of constipation
- high doses of osmotically active agents produce prompt bowel evacuation within 1–3 hours
- important that patients maintain adequate hydration by taking increased oral liquids to compensate for fecal fluid loss
Purgatives
- Magnesium citrate
- Sodium phosphate
ADEs of which laxative?
- hyperphosphatemia
- hypernatremia
- hypocalcemia
- hypokalemia
- may lead to cardiac arrhythmias
- may lead to acute renal failure
Sodium Phosphate
In which 4 patients should you not prescribe Sodium Phosphate?
- Frail / elderly
- Renal insufficiency
- Significant cardiac disease
- Unable to maintain adequate hydration during bowel preparation
Which laxative?
- used to clean colon before GI endoscopic procedures
- balanced, isotonic solutions contain an inert, nonabsorbable, osmotically active sugar with sodium sulfate, sodium chloride, sodium bicarbonate, and potassium chloride
- designed so that no significant intravascular fluid or electrolyte shifts occur
Polyethylene glycol (PEG)
Which laxative?
- safe for all patients
- solution should be ingested rapidly (2–4 L over 2–4 hours) to promote bowel cleansing
- treatment or prevention of chronic constipation
Polyethylene Glycol (PEG)
(MiraLAX)
Which laxative?
- Induce bowel movements through direct stimulation of the enteric nervous system and colonic electrolyte and fluid secretion
- may be required on a long-term basis
- Neurologically impaired
- Bed-bound patients in long-term care facilities
Cathartics (stimulant laxatives)
Which laxative?
•Long-term use is controversial
Stimulant laxatives (cathartics)
Which laxative?
- Aloe, senna, and cascara
- Occur naturally in plant
- Laxatives are poorly absorbed and after hydrolysis in the colon, produce a bowel movement in 6–12 hours
Anthraquinone Derivatives
(Laxative Stimulants)
Anthraquinone Derivatives (Laxative Stimulant)
- Chronic use causes what?
- There is concern these agents may cause what?
- Characteristic brown pigmentation of the colon (Melanosis Coli)
- Carcinogenic, but epidemiologic studies do NOT suggest a relation to colorectal cancer
Which laxative?
- Bisacodyl (Ducolax)
- treatment of acute and chronic constipation
- used in conjunction with PEG solutions for colonic cleansing prior to colonoscopy
- induces a bowel movement within 6–10 hours when given orally and 30–60 minutes when taken rectally
- minimal systemic absorption and appears to be safe for acute and long-term use**
Diphenylmethane Derivative
Acute and Chronic therapy w/ opioids may cause constipation due to what mechanism?
Decreasing intestinal motility
Which 3 Opioid Receptor Antagonists (peripherally acting)?
- do not readily cross the blood-brain barrier
- inhibit peripheral μ-opioid receptors without impacting analgesic effects within the central nervous system
- Methylnaltrexone bromide
- Alvinopan
- Naloxegol
Which Opioid Receptor Antagonist?
•approved for the treatment of opioid-induced constipation in patients receiving palliative care
Methylnaltrexone (Relistor)
Which Opioid Receptor Antagonist?
- approved for short-term use to shorten the period of postoperative ileus in hospitalized patients who have undergone small or large bowel resection
- no more than 7 days
- possible cardiovascular toxicity
Alvimopan (Entereg)
Which Opioid Receptor Antagonist?
•Opioid-induced constipation
- Dosage adjustment with renal impairment (CrCl < 60ml/min)
- Avoid use in severe hepatic impairment (Child-Pugh class C)
Naloxegol (Movantik)
- Acute diarrhea is how many days?
- Chronic diarrhea is how many days?
- Acute: <3 days
- Chronic: >14 days
Clinical Controversy
- Withholding food is considered inappropriate in pts w/ no signs of what?
- In osmotic diarrhea, what may control the problem?
- If the mechanism is ____, diarrhea persists
- Severe dehydration
- food
- secretory
What type of Antidiarrheal Agent?
- Antimotility
Opioid agonists
What type of Antidiarrheal Agent?
- Kaolin-pectin mixture
Absorbents
What type of Antidiarrheal Agent?
- Colloidal Bismuth Compounds
- Bile Salt-Binding Resins
- Octrotide
Antisecretory
What are the 4 types of Antidiarrheal Agents
- Antimotility
- Adsorbents
- Antisecretory
- Bacterial replacement and enzymes
Antidiarrheal Agents
- Should not be used in patients w/ what 3 things?
- Bloody diarrhea
- High fever
- Systemic toxicity
Antidiarrheals are used to treat which 2 conditions?
IBS and IBD
Which antidiarrheal agent?
- significant constipating effects
- increased colonic transit time and fecal water absorption
Opioid Agonists
Which antidiarrheal agent?
- nonprescription opioid agonist
- does not cross the blood-brain barrier
-
no analgesic properties or potential for addiction
*
Loperamide
Which antidiarrheal agent?
- higher doses have central nervous system effects
- prolonged use can lead to opioid dependence
Diphenoxylate
What type of antidiarrheal agent?
- Kaolin-pectin
- Adsorb nutrients, toxins, drugs, and digestive juices
Adsorbents
Which antidiarrheal agent?
- Mucosal Protective Agents
Colloidal Bismuth Compounds
What are the 3 Bile Salt-Binding Resins?
- cholestyramine
- colestipol
- colesevelam
Which bile salts bind to drugs and decrease their absorption?
Cholestyramine
Colestipol
4 ADEs of all Bile Salt Binding Resins
- bloating
- flatulence
- constipation
- fecal impaction
This drug does not appear to have a significant effect on absorption of other drugs (does not bind to bind to drugs and reduce their absorption)
Which drug?
Colesevelam (Bile salt-binding resins)
inhibits the secretion of hormones and transmitters
slows GI motility and inhibits gallbladder contraction
Which drug?
Somatostatin
What is the main clinical use of somatostatin (ocreotide)?
inhibits secretory diarrhea caused by endocrine tumor effects
3 “other uses” of Somatostatin (Octreotide - Antisecretory)
- pancreatic fistula
- pituitary tumors
- GI bleeding
ADEs of which drug?
- Steatorrhea
- Hypothyroidism from long term tx
- Bradycardia
Somatostatin (Octreotide - Antisecretory)
