Colon Pharm- Fitz

Question 1

GLP-2 analogue
MOA: binds enteric neurons and endocrine cells causing release of trophic hormones that increase mucosal epithelial growth leading to enhanced fluid and nutrient absorption

Answer 1

Teduglutide

Tx for short bowel syndrome

Question 2

Activates CIC-2:
Increased Cloride secretion-> retention of H2O in lumen–> looser stool
poor systemic absorption
FOUND IN BREAST MILK

Answer 2

Lubiprostone

use for chronic constipation or constipation predominant IBS

Question 3

Activates GC-C–> increased cGMP–>activates CFTR causing increased Cl secretion and retention of water in lumen
Poor systemic absorption
Black box warning in pediatrics

Answer 3

Linaclotide and Plecanatide

use for chronic constipation or constipation predominant IBS

Question 4

Voltage- independent inhibition of CFTR causing decreased Cl secretion–>increased absorption of H2O from lumen–> firmer stool

Answer 4

Crofelemer

use for diarrhea due to anti-HIV tx

Question 5

Synthetic analogue of SS (longer half life)

1. decreases 5HT stimulated, cGMP dependent Cl secretion
2. Decreases NT/hormone release
3. at low doses–> increases motility
4. at high doses–>decreases motility

Answer 5

Octreotide
On label: tx of tumurs
Off label: severe diarrhea d/t dumping syndrome, short bowel, vagotomy, AIDs

Question 6

COX Inhibitor
Decreases prostaglanding synthesis-> decreases cAMP–>decreases Cl secretion–> increase absorption of water from lumen leading to firmer stools
antimicrobial and binds enterotoxins

Answer 6

Bismuth Subsalicylate

Use for prevention and tx of traveler’s diarrhea

Question 7

Drugs are not absorbed so cause increased retention of water in lumen d/t osmosis–>looser stool

Answer 7

Osmotic Cathartics:
Lactulose, Magnesium Hydroxide, Sodium Phosphate, Polyethylene glycol

used for constipation (ESP when enteric nervous system has been disrupted)

Question 8

Osmotic Cathartic that decreases plasma ammonia concentrations
Used to tx portal systemic encephalopathy

Answer 8

Lactulose

Question 9

Bind unabsorbed bile acids to increase water retention

some pathologies cause decreased resorption of bile salts and result in osmotic diarrhea

Answer 9

Bile Acid Binding Resins

cholestyramine and colestipol

Question 10

Decrease reuptake of 5HT in ECL cells–> increae of 5HT in the synapse–> increase in primary afferent activity–> increase in peristalsis

Answer 10

SSRIs: Fuloxetine, Paroxetine, sertaline
use: constipation predominant IBS

Question 11

Attract water and increase stool mass

Dependend on normal fxn of the rest of the peristaltic reflex

Answer 11

Bulk Laxatives: Dietary fiber, methylcellulose, psyllium

Question 12

Unclear Mechanism- thought to stimulate the peristaltic reflex. Possibly d/t irritation

Answer 12

Contact (Irritant) Cathartics: Anthraquinone derivatives (cascara sagrada, danthron, senna), bisacodyl, castor oil

Question 13

Contact cathartic that works in both small and large intestine

Answer 13

Castor oil

Question 14

Decrease afferent stimulation via 5HT3 leading to decreased peristalsis

Answer 14

5HT3 antagonist: alosetron

use: diarrhea predominant IBS–ONLY AFTER EVERYTHING ELSE FAILS

Question 15

Activate presynaptic receptors of IPAN–> increases neurotransmitter release from myenteric neurons leading to increased peristalsis
Increases motility

Answer 15

5HT4 agonists
Tegaserod and Cisapride
Tegaserod: for constipation predominant IBS after all else fails
Cisapride: diabetic gastroparesis when all else fails

Question 16

Inhibit dopamine action (would inhibit ACh) –> increase actions of ACh in gut–> increase motility throughout entire gut

Answer 16

D2 receptor antagonists: domperidone and metoclopramide

Question 17

Most effective antidiarrheal drugs:

decrease motility and secretion by actin on mu receptor (agonists)

Answer 17

Opiates: diphenoxylate, loperamide

combo diphenoxylate with atropine to reduce abuse

Use for all types of diarrhea

Question 18

Antagonists of mu receptor; don’t cross BBB

Results in increased gastric motility

Answer 18

Alvimopan, methylnaloxone
Alvimopan- only short term (increased risk MI)
Methylnaloxone is for long term palliative care (i.e. opioid constipation)

Question 19

Decrease reuptake of NE from postganglionic sympathetic neurons–> increased activation of alpha2 receptors on presynaptic terminals of postganglionic parasympathetic nerves–> decreased ACh release–> decreased motility

Answer 19

TCAs: Amitriptyline, desipramine
use: diarrhea predominant IBS

Question 20

Antimuscarinic (Anti-ACh) causing decreased motility

Answer 20

Atropine (combo-ed with diphenoxylate)

Use: anti-diarrheal

Question 21

Stimulation of motilin receptors on smooth muscle causing activation of MMC

Answer 21

Macrolide Antibx: erythromycin

Use: constipation predominant IBS

Question 22

Surfactant–> increased mixing of water with stool

Answer 22

Docusate (stool softener)

Question 23

Lubricating stool softener

Answer 23

Mineral oil

Question 24

List the prokinetic drugs (act along the entire GI tract)

Answer 24

D2 receptor antagonists (domperidone and metoclopramide)
Macrolides: erythromycin
5HT4 agonists: cisapride

Question 25

List the anti-diarrheals:

Answer 25

opiates: loperamide, diphenoxylate and atropine
BABRs: cholestyramine, colestipol
SS analogue: Octreotide
Bismuth Subsalycilate
Crefelemer

Question 26

Classes of Cathartics and Laxatives:

Answer 26

Chloride Channel activators
Stool Softeners
Bulk Forming
Contact Irritant