Diarrhea, Abdominal Pain, and Constipation Pharm

Question 1

What is loperamide?

Answer 1

• Chemically related to opioids but does not exhibit analgesic/opiate like effects or appear to produce physical dependence

Question 2

What is the MOA of loperamide?

Answer 2

• Interferes with peristalsis
• Direct action on circular and longitudinal muscles of intestinal wall, slowing motility
• Slowed motility allows for fluid/electrolyte reabsorption and increasing bulk/density of feces

Question 3

What is diphenoxylate?

Answer 3

• Synthetic opiate agonist

Question 4

What is added to diphenoxylate? Why?

Answer 4

• Small quantity of atropine to discourage abuse/over doseage

Question 5

What is the MOA of diphenoxylate?

Answer 5

• Believed to exert effect locally and centrally on GI smooth muscle cell
• Inhibits GI motility and slows excess GI propulsion

Question 6

What is the MOA of eluxadoline?

Answer 6

• Agonist at opioid mu and kappa receptors in GI

- Antagonist at delta opioid receptor in GI (stomach, pancreas, biliary secretions decreased)

Question 7

What is the indication for eluxadoline?

Answer 7

• IBS-D

Question 8

What is the MOA of alosetron?

Answer 8

• Selectively blocks GI based 5-HT receptors

- Antagonism modulates regulation of visceral pain, colonic transit, and GI secretions

Question 9

What is the indication of alosetron?

Answer 9

• Chronic, severe IBS-D not responsive to other conventional therapies (women)

Question 10

What is crofelemer?

Answer 10

• Derived from dark red sap of Croton lechleri tree

Question 11

What is the MOA of crofelemer?

Answer 11

• Inhibits chloride ion secretion by blocking cAMP-stimulated CFTR and calcium activated chloride channels

Question 12

What is the indication for crofelemer?

Answer 12

• Non-infectious diarrhea in HIV/AIDS

Question 13

What are the two antimuscarinics used for abdominal pain?

Answer 13

• Hyoscyamine

- Dicyclomine

Question 14

What is the MOA of antimuscarinics?

Answer 14

• Competitively inhibit autonomic, postganglionic cholinergic receptors

Question 15

What is the indication of antimuscarinics?

Answer 15

• Abdominal pain/spasms

Question 16

What is the MOA for methylnaltrexone, naloxegol, and alvimopan?

Answer 16

• Peripheral mu-opioid receptor antagonists

Question 17

What are the indications for methylnaltrexone, naloxegol, and alvimopan?

Answer 17

• Opioid induced constipation
• Alvimopan- only for accelerating time to GI recovery following bowel resection surgery with primary anastomosis (prevention of postoperative ileus)

Question 18

What is the MOA of linaclotide?

Answer 18

• Selective guanylate cyclase agonist

Question 19

What are the indications of linaclotide?

Answer 19

• IBS-C

- Chronic idiopathic constipation

Question 20

What is the MOA of lubiprostone?

Answer 20

• PGE-1 derivative
• Increases intestinal fluid secretion by activating GI specific chloride channels in luminal cells of intestinal epithelium

Question 21

What are the indications of lubiprostone?

Answer 21

• IBS-C (women)
• CIC
• OIC

Question 22

How do bulk forming/hydrophilic colloidal agents work?

Answer 22

• Work to increase bulk-volumes and water content, thereby increasing GI motility
• Fiber can also support colonic bacteria, fermentation, and digestion

Question 23

What is the efficacy of bulk forming agents?

Answer 23

• 2-4 days

Question 24

What are stool softeners?

Answer 24

• Surfactant or emollient laxatives
• Docusate salts
• Mineral oil

Question 25

What is the MOA of stool softeners?

Answer 25

- Anionic surfactants --> softens and lubricates feces - Increases fluid secretion into GI tract - Decreases fluid reabsorption from GI tract

Question 26

What is the efficacy of stool softeners?

Answer 26

- 1-3 days | - Minimal laxative effect, softening mainly

Question 27

What are some stimulants?

Answer 27

- Senna - BIsacodyl - Castor oil - Glycerin - Sodium picosulfate

Question 28

What is the MOA of stimulants?

Answer 28

- Irritant to enterocytes, GI smooth muscle leading to inflammation - Promotes water/electrolyte accumulation in GI

Question 29

How is glycerin different?

Answer 29

- Is a tri-hydroxyl alcohol and functions as an irritant, an osmotic, and lubricant agent

Question 30

What is the efficacy of stimulants?

Answer 30

- Usually seen in 12-36 hours

Question 31

What are some saline agents used as laxitives?

Answer 31

- Magnesium salts | - Sodium phosphate

Question 32

What is the MOA of saline agents?

Answer 32

- Magnesium/phosphate ions poorly absorbed - Hyperosmolar solutions - Osmotically retain water in GI tract

Question 33

What are some osmotic agents used as laxitives?

Answer 33

- Lactulose - Magnesium citrate - Sorbitol - Polyethylene glycol

Question 34

What is the MOA of osmotic agents?

Answer 34

- Osmotically attract and retain increased water in colon increasing moisture, softness, and volume/bulk

Question 35

What is the efficacy of osmotic agents?

Answer 35

- 1-2 days

Question 36

What is lactulose given for?

Answer 36

- Severe liver disease patients (hyperammonemia)