GI Motility 2

Question 1

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

Answer 1

Purgatives

• Magnesium citrate
• Sodium phosphate

Question 2

ADEs of which laxative?

• hyperphosphatemia
• hypernatremia
• hypocalcemia
• hypokalemia
• may lead to cardiac arrhythmias
• may lead to acute renal failure

Answer 2

Sodium Phosphate

Question 3

In which 4 patients should you not prescribe Sodium Phosphate?

Answer 3

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

Question 4

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

Answer 4

Polyethylene glycol (PEG)

Question 5

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

Answer 5

Polyethylene Glycol (PEG)

(MiraLAX)

Question 6

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

Answer 6

Cathartics (stimulant laxatives)

Question 7

Which laxative?

•Long-term use is controversial

Answer 7

Stimulant laxatives (cathartics)

Question 8

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

Answer 8

Anthraquinone Derivatives

(Laxative Stimulants)

Question 9

Anthraquinone Derivatives (Laxative Stimulant)

• Chronic use causes what?
• There is concern these agents may cause what?

Answer 9

• Characteristic brown pigmentation of the colon (Melanosis Coli)
• Carcinogenic, but epidemiologic studies do NOT suggest a relation to colorectal cancer

Question 10

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**

Answer 10

Diphenylmethane Derivative

Question 11

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

Answer 11

Decreasing intestinal motility

Question 12

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

Answer 12

• Methylnaltrexone bromide
• Alvinopan
• Naloxegol

Question 13

Which Opioid Receptor Antagonist?

•approved for the treatment of opioid-induced constipation in patients receiving palliative care

Answer 13

Methylnaltrexone (Relistor)

Question 14

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

Answer 14

Alvimopan (Entereg)

Question 15

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)

Answer 15

Naloxegol (Movantik)

Question 16

• Acute diarrhea is how many days?
• Chronic diarrhea is how many days?

Answer 16

• Acute: <3 days
• Chronic: >14 days

Question 17

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

Answer 17

• Severe dehydration
• food
• secretory

Question 18

What type of Antidiarrheal Agent?

• Antimotility

Answer 18

Opioid agonists

Question 19

What type of Antidiarrheal Agent?

• Kaolin-pectin mixture

Answer 19

Absorbents

Question 20

What type of Antidiarrheal Agent?

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

Answer 20

Antisecretory

Question 21

What are the 4 types of Antidiarrheal Agents

Answer 21

• Antimotility
• Adsorbents
• Antisecretory
• Bacterial replacement and enzymes

Question 22

Antidiarrheal Agents

• • Should not be used in patients w/ what 3 things?

Answer 22

• Bloody diarrhea
• High fever
• Systemic toxicity

Question 23

Antidiarrheals are used to treat which 2 conditions?

Answer 23

IBS and IBD

Question 24

Which antidiarrheal agent?

• significant constipating effects
• increased colonic transit time and fecal water absorption

Answer 24

Opioid Agonists

Question 25

Which antidiarrheal agent? * **nonprescription** opioid agonist * **does not cross the blood-brain barrier** * **no analgesic properties or potential for addiction** *

Answer 25

Loperamide

Question 26

Which antidiarrheal agent? * **higher doses have central nervous system effects** * **prolonged use can lead to opioid dependence**

Answer 26

Diphenoxylate

Question 27

What type of antidiarrheal agent? * **Kaolin-pectin** * **Adsorb nutrients, toxins, drugs, and digestive juices**

Answer 27

**Ad**sorbents

Question 28

**Which antidiarrheal agent?** * Mucosal Protective Agents

Answer 28

Colloidal Bismuth Compounds

Question 29

What are the 3 Bile Salt-Binding Resins?

Answer 29

**- cholestyramine** **- colestipol** **- colesevelam**

Question 30

Which bile salts bind to drugs and decrease their absorption?

Answer 30

Cholestyramine Colestipol

Question 31

4 ADEs of all Bile Salt Binding Resins

Answer 31

* bloating * flatulence * constipation * fecal impaction

Question 32

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?

Answer 32

**Colesevelam** (Bile salt-binding resins)

Question 33

**inhibits the secretion of hormones and transmitters** **slows GI motility and inhibits gallbladder contraction** Which drug?

Answer 33

Somatostatin

Question 34

What is the **main clinical use of somatostatin** (ocreotide)?

Answer 34

inhibits secretory diarrhea caused by **endocrine tumor effects**

Question 35

3 **"other uses"** of Somatostatin (Octreotide - Antisecretory)

Answer 35

* **pancreatic fistula** * **pituitary tumors** * **GI bleeding**

Question 36

ADEs of which drug? * **Steatorrhea** * **Hypothyroidism from long term tx** * **Bradycardia**

Answer 36

**Somatostatin** (Octreotide - Antisecretory)