Lower GI Pharmacology Flashcards Preview

GI > Lower GI Pharmacology > Flashcards

Flashcards in Lower GI Pharmacology Deck (40):
1

Best anti-diarrheal agent
Poorly penetrates the CNS
u receptor agonist

Loperamide (Imodium)

2

Anti-diarrheal agonist
Can produce CNS effects -- abuse potential given with atropine

Diphenoxylate (Lomotil)

3

Absorbs water and increases stool bulk

Bulk forming and absorbents: Kaolin (clay) + pectin (Kaopectate); also fiber

4

Includes bismuth which is thought to have anti-secretory, anti-inflammatory and anti-microbial effects
Use to prevent and treat traveler's diarrhea

Bismuth subsalicylate (pepto bismol)

5

Somatostatin analog; inhibits secretory diarrhea d/t hormone-secreting tumors of the pancreas and GI tract

Octreotide (Sandostatin)

6

Off-label uses for Octreotide

Post operative dumping syndrome, variceal bleeding, other forms of diarrhea

7

3 mechanims laxatives work by

1. enhancing the retention of intraluminal fluid by hydrophilic or osmotic mechanisms
2. decreasing net absorption or increase secretion of fluid by effects on small- and large-bowel fluid and electrolyte transport
3. altering motility

8

Mechanism of dietary fiber

Fiber fermented by the colon bacteria produces short chain fatty acids which are somewhat prokinetic and trophic for the endothelium
Fermentation increases stool bacterial mass

**Non-fermented fiber retains water and increases stool bulk

9

Inorganic salts that are not absorbed causes water retention
Bowel cleansing products

Milk of Magnesia (MgOH2)

10

Osmotic laxative
Unabsorbed carbohydrate metabolized to short chain fatty acids by gut bacteria

Lactulose

11

Another use of Lactulose

Portal-systemic encephalopathy -- can decrease ammonia levels

12

Not absorbed, remains in the lumen
Retain water due to osmotic grade
May be given with isotonic Na and K salts (prevent net ionic shift)

Polyethylene Glycol (PEG, Miralax)

13

Anionic surfactant, lowers surface tension

Ducosate salts (bilax, colace)

14

Stimulant laxatives
Cause mucosa inflammation/irritation

Contact cathartics

15

Laxative
Diphenylmethane, Prodrug - converted by bowel esterases
Acts on large intestine

Bisacodyl

16

Laxative
Anthraquinone cathartics, Prodrug - requires colonic bacteria
Plant derivative
Acts on large intestine

Senna

17

Prostanoid
Activates chloride channels in the intestine to increase fluid secretion
Not absorbed and only acts in intestinal lumen
Used for adult chronic constipation and women with IBS

Lubiprostone

18

Binds and activates guanylate cyclase C receptor on the luminal surface of intestinal epithelial cells to increase intracellular and extracellular cGMP --> chloride and bicarb secretion, extracellular cGMP may decrease visceral pain

Used for chronic idiopathic constipation, irritable bowel syndrome with constipation

Linaclotide

19

Opioid receptor antagonist
For constipation

Methylnaltrexone

20

5HT3 receptor antagonist used for diarrhea dominant irritable bowel syndrome (restricted use)

Alosetron

*Concern with increased incidence of ischemic colitis with use

21

Therapeutic goals of IBD

1. Treat acute attacks
2. Maintain remission - long term management
3. Treat complications

22

Used for mod-severe acute attacks
Disadvantage -- systemic affects

Prednisone

23

Enteric release steroid used for Crohn's disease to target the inflamed gut --> less side effects

Budesonide

24

5-aminosalicylate
Delayed time or pH dependent release
For mild to moderate UC (less effective for Crohn's)

Mesalamine

25

5-aminosalicylate
Prodrugs -- converted to Mesalamine

Olsalazine
Sulfasalazine

26

SE of Sulfasalazine

Related to sulfapyridine and include fever, malaise, vomiting, headache

27

SE of Mesalamine

Relatively infrequent and minor and include headache, dyspepsia, and skin rash

28

SE of Olsalazine

Diarrhea

29

Which patients should you avoid 5-aminosalicylates in?

Contraindicated in patients allergic to salicylate

30

Thiopurine antimetabolites for IBD

6-mercaptopurine
Azathioprine

31

What is azathioprine metabolized to?

6-mercaptopurine

32

SE of Azathioprine?

Numerous, bone marrow suppression, vomiting, jaundice, pancreatitis
Used for both UC and Crohn's

33

Dihydrofolate reductase inhibitor, off label use for Crohn's

Methotrexate

34

Calcineurin inhibitor off label use for ulcerative colitis

Cyclosporine

35

Immunoglobulin against TNFalpha
Used for moderate to severe Crohn's and UC

Infliximab

36

SE of Infliximab

Lupus-like syndrome, delayed hypersensitivity, infection
Increased URI and increased incidence of non-Hodgkin lymphoma

37

Recombinant human IgG1 monoclonal antibody against TNFalpha
Used for IBD

Adalimumab (Humira)

38

A pegylated humanized antibody Fab fragment of TNFalpha monoclonal antibody
Used for IBD

Certolizumab pegol (Cimzia)

39

Monoclonal antibody against 4-integrin
Binds 4-integrin and reduces leukocyte extravasation

Natalizumab (Tysabri)

40

Why isn't Natalizumab used very often?

Increases the risk of progressive multifocal leukoencephalopathy (PML)