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Flashcards in GI drugs Deck (85):
1

Antacids drugs

Al (OH)3
Mg (OH)2
CaCO3

2

Antacids description

Weak bases increase the pH of the stomach
->**pepsin inactivation**

3

Antacids Mechanism

Forms a salt and H2O
Very fast effect

4

Antacids Indication

GERD
GASTRITIS
PUD

5

Antacids PK

AL(OH)3 may decrease bioavailability of tetracyclines, digoxin, and antimuscarinics

6

Antacids contraindications

Al(OH)3 -> constipation
Mg(OH)2 -> diarrhea

CaCO3 -> Nephrolithiasis and constipation -> fecal impaction

7

H2 blockers

Cimetidine (1st gen)
2nd gen:
Famotidine
Ranitidine
Nizatidine

8

H2 blockers description for peptic ulcer disease

90% reduction of HCl** secretion after a *single* dose

Promote healing of ulcers

Recurrence is common when monotherapy is stopped

9

H2 blockers mechanism for PUD

Block the Gs mediated increase in cAMP that activatges the H+/K+ pump

2nd gen do not inhibit CYP450 and are longer actring than cimetidine

10

H2 PUD Indication

Acute stress ulcer
Prevent aspiration PNA preoperatively

11

H2 PUD PK

Cimetidine inhibits CYP450 ->many drug interactions

12

H2 PUD adverse/contraindications

**Cimetidine crosses the BBB and is prolactin simulating and anti-androgenic -> gynecomastia*

Nausea, HA & dizziness

13

Proton pump inhibitor PUD drugs

Omeprazole
Esomeprazole
Lansoprazole
Rabeprazole
Pantoprazole
...basically prazoles

14

Proton pump inhibitor PUD description

Nearly 100% reduction in HCl

Activated after transport into parietal cell (**prodrug**)

Also support platelet aggregation and maintain clot integrity -> **hemorrhagic ulcers**

15

Proton pump inhibitor PUD mechanism

*Covalent bond* formation with cysteine residue on H+/K+ ATPase within the parietal cell canaliculi -> *irreversible* inactivation

16

Proton pump inhibitor PUD Indication

GERD
Gastric ulcers
MEN I
ZE syndrome
H pylori (with antibiotics)
NSAID induced ulcers

17

Proton pump inhibitors PUD PK

Omeprazole inhibits Warfarin, phenytoin, diazepam and cyclosporine

18

Proton pump inhibitor PUD Adverse/Contraindications

Nausea and diarrhea are possible, but they are generally well tolerated

Prolonged use of PPI and H2 -> **decrease bioavailability and B12, disgoxin and ketoconazole** (acid required for absorption)

GI and respiratory infections
Pancreatitis
Hepatotoxicity
Interstitial nephritis

19

Antimicrobials used against H pylori

Clarithromycin
Amoxicillin
Metronidazole
Tetracycline

20

Clarithromycin, Amoxicillin, Metronidazole, Tetracycline PUD description

Eradication of H pylori -> rapid healing (infection documented with endoscopy, serology or urea breath test)

21

Clarithromycin, Amoxicillin, Metronidazole, Tetracycline PUD Mechanism

Used as part of *triple therapy* regimen for 2 weeks -> 2 antibiotics + PPI

22

Clarithromycin, Amoxicillin, Metronidazole, Tetracycline PUD Indication

H pylori infection

Other combo: bismuth, + 2 antibiotics + PPI or ranitidine

23

Mucosal protective agents PUD drugs

Sucralfate
Bismuth subsalicylate
Misoprostol

24

Sucralfate PUD description

Disaccharide; **Requires acid to be activated** ... do not give with PPI's or H2 blockers

25

Misoprostol PUD description

**PGE1 analogue**
**decrease HCl secretion** and increase mucin & bicarb production via activation of Gi -> decrease cAMP

26

Sucralfate, Bismuth subsalicylate, Misoprostol PUD mechanism

Polymerization and selective binding to necrotic tissue *forms a physical barrier* to acid

Stimulates PG synthesis

27

Sucralfate, Bismuth subsalicylate, Misoprostol Indication

Ulcers

Bismuth may also be helpful in H pylori infections (antimicrobial)

Misoprostol is approved for *NSAID* induced ulcers but has been replaced by *H2 blockers and PPI's*

28

Misoprostol adverse/contraindications

Diarrhea
**Abortion** (contraindicated in pregnancy)
Exacerbation of IBD

29

Prokinetic GI drugs

Neostigmine, Bethanechol
Metoclopramide
Cisapride
Erythromycin

30

Neostigmine GI description and indication

Cholinomimetic agent
indication- Pseudoobstruction in hospitalized patients

31

Bethanechol GI Description and indication

Cholinomimetic agent
M receptor only
indication- Gastroparesis

32

Metoclopramide Prokinetic GI Description/Mechanism

Accelerates gastric emptying and intestinal motility

5-HT and D2 blocker
**5HT4=prokinetic**

33

Metoclopramide GI indication

Gastroparesis
Emesis (in higher doses) associated with chemo

34

Metoclopramide GI ae/contraindication

Sedation, Diarrhea
Galactorrhea
**EXTRAPYRAMIDAL SYMPTOMS**

35

Cisapride prokinetic GI description/mechanism

Stimulates ACh secretion

5-HT agonist

36

Cisapride GI indication

GERD, constipation
Gastroparesis

37

Cisapride ae/contraindications GI

Can cause arrhythmia
Avoid in patients with long QT*********

38

Erythromycin GI description/mechanism

Marcolide antibiotic

**Motilin receptor agonist**

39

Erythromycin GI indication

Gastric emptying before *endoscopy*
Prokinetic agent

40

Erythromycin GI PK

give IV
Short term use

41

Erythromycin GI ae/contraindication

May *develop tolerance* in gastroparesis

42

Opioid agonist anti diarrheals drugs

Loperamide
Diphenoxylate

43

Opioid agonist anti diarrheal description/mech.

Decrease gut motility

Inhibit ACh release

Atropine is added to diphenoxylate to reduce abuse potential

44

Bile acid Binding resins

Cholestyramine
Colestipol
Colesevelam

45

Cholestyramine, Colestipol, Colesevelam GI description/mech

Used in lower cholesterol
Also *prevent secretory diarrhea*

Bile salts stimulate Cl- secretion in the colon (cAMP)
Resins form insoluble complexes with bile acids that are no longer able to stimulate this excess secretion

46

Octreotide description/mech/indication

Somatostatin analog, anti diarrheal
**Carcinoid syndrome: wheeze, flushing, diarrhea, and right side heart murmurs**
VIPoma -> copious diarrhea

Long acting

Indication- **Carcinoid tumor, VIPoma, Acute variceal bleed**

47

Octreotide GI ae/contraind.

Reduces both endocrine and exocrine pancreatic activity -> nausea, cramps, steatorrhea

48

Bismuth subsalicylate GI

can be used as an anti diarrheal

49

Opioid laxatives

Alvimopan
Methylnaltrexone

50

Alvimopan, Methylnaltrexone GI description/mech

Laxatives
Block GI mu-receptors without entering CNS

Increase ACh and Peristalsis**

51

Lubiprostone GI description and indication

Laxative
Increase fluid content by stimulating Cl- secretion

Indication -> constipation and IBS

52

Cl- channel activator laxative

Lubiprostone

53

Stimulant laxatives

Senna
Bisacodyl
Castor Oil

54

Senna indication GI

Laxative
Used with docusate for opioid inducted constipation **

55

Stimulant laxative ae

Cramping
Prolonged use -> perceived need

56

Osmotic laxatives

Mg2+ salts
Mg(OH)3

Lactulose
Polyethylene Glycol

57

Osmotic laxative descrip

Osmotic action draws water into the lumen which stimulates motility

58

Mg2+ salt GI mechanism

laxative
Saline cathartics

59

Lactulose GI mechanism

Synthetic disaccharide degraded by bacteria

60

Polyethylene glycol GI mech

Radiology and endo

61

Osmotic laxative indication

Simple constipation
Prep for endoscopy

62

Lactulose indication

**Hepatic encephalopathy -> draws out NH3 preventing hyperammonemia
Acidification of gut lumen traps NH4+***

63

Softener laxatives

Docusate
Mineral oil
Glycerine

64

Docusate, Mineral oil, Glycerine description and indication GI

Emulsify and soften stool making it easier to pass
Laxatives

Combined with stimulant in opioid induced constipation

65

Methylcellulose, Psyllium, Bran description/mech

Bulk forming laxatives
Insoluble, indigestible derivatives from fruits and vegetables

Increased H2O retention to increase stool bulk
**Distension of the bowel -> stimulation of peristalsis**

66

Methylcellulose, Psyllium, Bran GI PK

Bulk forming laxatives
Require high fluid intake

67

Methylcellulose, Psyllium, Bran contraindication

**Do not use with opioid induced constipation**

68

Ondansetron (Zofran), Granisetron description/indication

Anti emetics
5HT3 blockers
Autocoid with action in the gut and CNS

Indication- moderate to severe *emesis associated with chemotherapy*
Post op nausea/vomiting

69

Aprepitant GI

Anti emetic NK1 blocker
Description- **CNS action at neurokinin 1 receptors (substance P)
Indication - *early and delayed emesis* in chemo

ae/contra - dizziness, fatigue, diarrhea, CYP interactions

70

Dexamethasone, Methylprednisolone GI

Anti emetic corticosteroids
*Combined with Odansetron* to provide greater anti emesis
Indication - chemotherapy induced nausea/vomiting

71

Diphenhydramine, Meclinzine, Cyclizine GI

Anti emetic H1 blockers

Indicaton - Motion sickness, chemotherapy induced nausea/vomiting

72

Scopolamine GI

Anti emetic anti-muscarinic

DOC for emesis associated with motion sickness

73

Prochlorperazine, Promethazine, Droperidol GI

Anti emetic D2 blockers
D2 and M blocker
Indication - emesis
AE- **extrapyramidal symptoms** & hypotension

74

Lorazepam, Alprazolam, Diazepam GI

Anti emetic Benzos
Beneficial effect may be due to *sedative, anxiolytic, and amnesic properties*
Indication - *anticipatory N/V*

75

Dronabinol GI

Anti emetic cannabinoids
Central acting anti emetic
Mechanism-THC
Indication - Chemoinduced nausea/vomit

76

Sulfasalazine, Balsalzide, Mesalamine GI

Drugs for IBD, aminosalicylates

Sulfa derivative prodrug
Releases *sulfapyridine* and *5-ASA (aminosalicylic acid)*

Mesalamine = 5-ASA

Mech- 5-ASA inhibits IL-1 & TNF alpha****

Use: Crohn's, Ulcerative colitis

AE:
Avoid in patients with sulfa allergy
Due to sulfapyridine:
N/V/D, hypersensativity reactions, **BM suppression**

77

Methotrexate, Mercaptopurine, Azathioprine GI

Drugs for IBD, immuno-modulators
Description-inhibits purine synthesis-> specific for S phase; generalized immune suppression

MTX inhibits DHF reductase**
6-MP promotes apoptosis**

Use: Crohn's, Ulcerative Colitis

Aziothioprine converts to 6-MP

AE:
MTX -> toxicity rare
6MP->can cause GI mucositis, hepatotoxicity and myelosuppression

78

Infliximab, Adalimumab GI

Drugs for IBD
**Anti TNF alpha**
Blocks the action of TNF alpha, a principle mediator of Crohn's

Used in acute flare ups of Crohn's and fistulas**
RA
Given IV

AE/contraindication->**Reactivation of latent TB**
Fever, chills, urticaria, hypotension
Development of Ab's

79

Natalizumab GI

Drug for IBD, Anti-integrin

Blocks *leukocyte integrins*

Used in acute flare ups of Crohn's and fistulas
RA

AE/Contraindication-> ***Progressive multifocal leukoencephalopathy***

80

Hydrocortisone, Prednisone, Prednisolone, Budesonide GI

Drugs for IBD, glucocorticoids

General *anti-inflammatories*
Budesonide->controlled release in the distal ileum and colon

**Inhibit TNF alpha, IL-1, IL-8**

Used for acute cases of IBD

81

Alosetron GI

Drug for IBS, 5-HT3 blocker
*Long acting->IBS-D*
Decreases smooth muscle activity

Indication-> IBS-diarrhea and/or constipation
Chronic symptoms with no structural abnormality

Treatment: symptomatic

AE/contraindications-. **Ischemic colitis**

82

DIcyclomine, Glycopyrrolate, Methscopolamine, Hyoscyamine GI

Drugs for IBS; Anticholinergics
Non-selective IBS-D

Indication-
IBS-diarrhea and/or constipation
Chronic symptoms with no structural abnormality
Treatment:symptomatic

83

Loperamide GI

Drug for IBS; Opioid agonist
**Decrease gut motility** -> IBS-D
Inhibits ACh release

Indication-
IBS-diarrhea and/or constipation
Chronic symptoms with no structural abnormality
Treatment: symptomatic

AE-> negligible CNS effects

84

Lubiprostone GI

Drug for IBS; Cl- Channel Activator
IBS-C
Increase fluid content by *Stimulating Cl- secretion*

Indication -
IBS - diarrhea and or constipation
Chronic symptoms with no structural abnormality
Treatment: symptomatic

85

Pancrelipase GI

Pancreas enzyme; drug for IBS
Replacement enzyme
Increases absorption
Indication -> chronic pancreatitis, etc.