GI Motility 2 Flashcards Preview

P2 E2 Shea > GI Motility 2 > Flashcards

Flashcards in GI Motility 2 Deck (45)
Loading flashcards...
1
Q

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
A

Purgatives (Osmotic - nonabsorbably sugars/salts)

  • Magnesium citrate
  • Sodium phosphate
2
Q

ADEs of which laxative?

  • hyperphosphatemia
  • hypernatremia
  • hypocalcemia
  • hypokalemia
  • may lead to cardiac arrhythmias
  • may lead to acute renal failure due to tubular deposition of calcium phosphate (nephrocalcinosis)
A

Sodium Phosphate

(Purgative - Osmotic - Nonabsorbable sugars/salts)

3
Q

In which 4 patients should you not prescribe Sodium Phosphate?

(Purgative - Osmotic - Nonabsorbable sugars/salts)

A
  • Frail / elderly
  • Renal insufficiency
  • Significant cardiac disease
  • Unable to maintain adequate hydration during bowel preparation
4
Q

Which laxative?

  • complete colonic cleansing before gastrointestinal 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
A

Polyethylene glycol (PEG)

5
Q

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
  • smaller doses of this powder may be mixed with water or juices (17 g/8 oz) and ingested daily
  • does not produce significant cramps or flatus
A

Polyethylene Glycol (PEG)

(MiraLAX)

6
Q

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
A

Cathartics (stimulant laxatives)

7
Q

Which laxative?

  • Long-term use is controversial
  • Newer studies do not report damage to the enteric nervous system like earlier studies
  • Nerve damage may be the cause of the constipation rather than the result of using laxatives
  • Patients requiring regular use of laxatives may still need to be monitored for these effects
A

Stimulant laxatives (cathartics)

8
Q

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 when given orally and within 2 hours when given rectally
A

Anthraquinone Derivatives

(Laxative Stimulants)

9
Q

Anthraquinone Derivatives (Laxative Stimulant)

  • Chronic use causes what?
  • There is concern these agents may cause what?
A
  • Characteristic brown pigmentation of the colon (Melanosis Coli)
  • Carcinogenic, but epidemiologic studies do NOT suggest a relation to colorectal cancer
10
Q

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**
A

Diphenylmethane Derivative

11
Q

Acute and Chronic therapy w/ opioids may cause constipation due to what mechanism?

A

Decreasing intestinal motility, which results in prolonged transit time & increased absorption of fecal water

12
Q

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
A
  • Methylnaltrexone bromide
  • Alvinopan
  • Naloxegol
13
Q

Which Opioid Receptor Antagonist?

  • approved for the treatment of opioid-induced constipation in patients receiving palliative care for advanced illness who have had inadequate response to other agents
  • Dosage adjustment with severe renal impairment (CrCl < 30ml/min)
A

Methylnaltrexone (Relistor)

14
Q

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
A

Alvimopan (Entereg)

15
Q

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)
  • Contraindicated in patients with GI obstruction
A

Naloxegol (Movantik)

16
Q

Name a few drugs which cause diarrhea

A
  • Laxatives (duh)
  • Auranofin (gold salt)
  • Antibiotics (Clinda, tetracyclines, Sulfonamides, any broad spectrum)
  • Antihypertensives
  • Cholinergics
  • Cardiac agents (digoxin)
  • NSAIDs
  • Misoprostol
  • PPIs
17
Q
  • Acute diarrhea is how many days?
  • Chronic diarrhea is how many days?
A
  • Acute: <3 days
  • Chronic: >14 days
18
Q

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
A
  • Severe dehydration
  • food
  • secretory
19
Q

What type of Antidiarrheal Agent?

  • Antimotility
A

Opioid agonists

20
Q

What type of Antidiarrheal Agent?

  • Kaolin-pectin mixture
A

Absorbents

21
Q

What type of Antidiarrheal Agent?

  • Colloidal Bismuth Compounds
  • Bile Salt-Binding Resins
  • Octrotide
A

Antisecretory

22
Q

What are the 4 types of Antidiarrheal Agents

A
  • Antimotility
  • Adsorbents
  • Antisecretory
  • Bacterial replacement and enzymes
23
Q

Antidiarrheal Agents

  • Safe to use for mild to moderate acute diarrhea
  • Should not be used in patients w/ what 3 things?
    • Due to risk of worsening the underlying condition?
    • Discontinue in pts whose diarrhea is worsening despite therapy
A
  • Bloody diarrhea
  • High fever
  • Systemic toxicity
24
Q

Antidiarrheals are used to treat which 2 conditions?

A

IBS and IBD

25
Q

Which antidiarrheal agent?

  • significant constipating effects
  • increase colonic phasic segmenting activity through inhibition of presynaptic cholinergic nerves in the submucosal and myenteric plexuses and lead to increased colonic transit time and fecal water absorption
  • decrease mass colonic movements and the gastrocolic reflex
A

Opioid Agonists

26
Q

Which antidiarrheal agent?

  • nonprescription opioid agonist
  • does not cross the blood-brain barrier
  • no analgesic properties or potential for addiction
  • tolerance to long-term use has not been reported
  • administered in doses of 2 mg taken one to four times daily
A

Loperamide

27
Q

Which antidiarrheal agent?

  • prescription opioid agonist
  • no analgesic properties in standard doses
  • higher doses have central nervous system effects
  • prolonged use can lead to opioid dependence
A

Diphenoxylate

28
Q

Which antidiarrheal agent?

  • Commercial preparations commonly contain small amounts of atropine to discourage overdosage (2.5 mg diphenoxylate with 0.025 mg atropine)
  • anticholinergic properties of atropine may contribute to the antidiarrheal action
A

Diphenoxylate

29
Q

What type of antidiarrheal agent?

  • Kaolin-pectin
  • Polycarbophil
  • Attapulgite (removed from market)
  • Effectiveness unproven
  • Adsorb nutrients, toxins, drugs, and digestive juices
A

Adsorbents

30
Q

Which antidiarrheal agent?

  • Mucosal Protective Agents
A

Colloidal Bismuth Compounds

31
Q

Bile Salt-Binding Resins

  • Conjugated bile salts are normally absorbed where?
  • Disease of this location (Crohn’s Disease) or surgical resection leads to malabsorption of bile salts, which may cause what?
A
  • terminal ileum
  • colonic secretory diarrhea
32
Q

What are the 3 names of the Bile Salt Binding Resins?

A
  • cholestyramine
  • colestipol
  • colesevelam
33
Q

Which antidiarrheal agent?

  • decrease diarrhea caused by excess fecal bile acids
  • powder and pill formulations that may be taken one to three times daily before meals
A

Bile Salt Binding Resins

  • Cholestyramine
  • Colestipol
  • Colesevelam
34
Q

4 ADEs of Bile Salt Binding Resins

A
  • bloating
  • flatulence
  • constipation
  • fecal impaction
35
Q

Bile Salt Binding Resins

  • Patients w/ diminished circulating bile acid pools, further removal of bile acids may lead to what?
A

exacerbation of fat malabsorption

36
Q

Which 2 Bile Salt Binding Resins?

  • bind a number of drugs and reduce their absorption
  • not be given within 2 hours of other drugs
A
  • Cholestyramine
  • Colestipol
37
Q

Which Bile Salt Binding Resin?

  • does not appear to have significant effects on absorption of other drugs
A

Colesevelam

38
Q

Antisecretory : Octreotide

Which drug?

  • 14-amino-acid peptide released in the gastrointestinal tract and pancreas from paracrine cells, D cells, and enteric nerves as well as from the hypothalamus
A

Somatostatin

39
Q

What are the 3 key regulatory peptide physiologic effects of Somatostatin?

A
  • inhibits the secretion of numerous hormones and transmitters (gastrin, glucagon. insulin)
  • reduces intestinal fluid secretion and pancreatic secretion
  • slows gastrointestinal motility and inhibits gallbladder contraction
40
Q

Which drug?

  • reduces portal and splanchnic blood flow.
  • inhibits secretion of some anterior pituitary hormones.
  • clinical usefulness is limited by its short half-life in the circulation (3 minutes) when it is administered by intravenous injection
A

Somatostatin

41
Q

Which drug?

  • Inhibition of Endocrine Tumor Effects
  • Two gastrointestinal neuroendocrine tumors (carcinoid, VIPoma) cause secretory diarrhea and systemic symptoms such as flushing and wheezing
A

Somatostatin (Octreotide)

42
Q

Antisecretory: Octreotide - Somatostatin

  • Low doses do what?
  • Higher doses do what?
  • Higher doses for the tx of diarrhea due to vagotomy or dumping syndrome as well as for diarrhea caused by what 2 conditions?
  • Low doses to stimulate small bowel motility in pts w/ small bowel bacterial overgrowth or intestinal pseudo-obstruction secondary to what condition?
A
  • Low: stimulate motility
  • Higher: inhibit motility
  • short bowel syndrome / AIDs
  • Scleroderma
43
Q
A
44
Q

3 “other uses” of Somatostatin (Octreotide - Antisecretory)

A
  • inhibits pancreatic secretion-value in patients with pancreatic fistula
  • treatment of pituitary tumors (eg, acromegaly)
  • gastrointestinal bleeding (decreases splanchnic blood flow-vapreotide)
45
Q

ADEs of which drug?

  • Steatorrhea (can lead to fat soluble vitamin deficiency)
  • sludge or gallstones in over 50% of pts
  • hyperglycemia / hypoglycemia (less frequent)
  • Hypothyroidism from long term tx
  • Bradycardia
A

Somatostatin (Octreotide - Antisecretory)