GI Drugs Flashcards Preview

Pharmacology > GI Drugs > Flashcards

Flashcards in GI Drugs Deck (40):
1

what do acid peptic diseases compose of

peptic ulcer (duodenal and gastric), gastroesophageal reflux, zollinger ellison syndrome (ZES)

2

pathologies that causes peptic ulcers

- gastric acid
- decreased mucosal resistance to acid
- H pylori infection
- NSAIDs
- concurrent use of warfarin and corticosteroids
- stress esp if older than 65
- lifestyle
- gastrinoma - gastrin secreting tumor

3

what do peptic disease do to the surface of GI tract

erodes and ulcerates the mucosal lining

4

therapeutic choices for peptic ulcer diseases and their functions

A HAM
- Antacids: neutralizes acid
- H2 antagonist and Proton Pump Inhibitor - reduces gastric acid secretion
- Antimicrobial treatments - eradicate H pylori infection
- Mucosal protective agents - augment mucosal surface defense

5

mechanism of gastric antacids

they are weak bases that react with gastric HCl to form water and salt --> increase in pH --> quick relief of symptoms

6

name the antacids

CAM

Calcium Carbonate
Aluminum Hydroxide
Magnesium Hydroxide

7

adverse effects of each antacids

- Calcium Carbonate --> Hypercalcemia which leads to nephrolithiasis and constipation --> fecal compaction

- Aluminum Hydroxide --> form aluMINIMUM chloride that is insoluble --> MINIMUM amount of feces --> constipation and Hypophosphatemia

- Magnesium Hydroxide --> for Mg salt which is poorly absorbed and causes diarrhea (Mg -- Must go to the bathroom)

8

clinical correlates of antacids and drug absorption

- increases oral absorption of weak bases (quinidine)

- decreases oral absorption of weak acids (warfarin)

- decreases oral absorption of Ca, Mg, and Al molecules --> chelate tetracycline

9

what are some factors that enhance gastric acid secretion and via what mechanism

Histamine, Acetylcholine, and Gastrin via H+/K+ ATPase pump

10

what are the H2 receptor blockers

FRaNC

Famotidine
Ranitidine
Nizatidine
Cimetidine

11

how effective are H2 receptor blockers/mechanism

they are effective at decreasing gastric acid secretion but have no effect on gastric emptying time

12

of all the H2 receptor blockers, which ones are longer acting/more potent

all but cimetidine

13

clinical uses of H2 receptor blockers

- promote healing of duodenal and gastric ulcers
- relieve gastro esophageal reflux
- given preoperatively to prevent aspiration pneumonia

14

adverse effects of H2 blockers excluding cimetidine

nausea, headache, dizziness

15

adverse of H2 blocker cimetidine

- inhibitor of CYP450 enzymes
- antiandrogenic effects - gynecomastia, elevated prolactin levels, decreased libido
- confusion in older people
- decrease renal excretion of creatinine

16

since Cimetidine is a CYP450 inhibitor, what drugs does it affect

-warfarin
-procainamide
-phenytoin
-benzos
-theophylline
-imipramine
-quinidine

17

what are the proton pump inhibitors

PROLE PRAZOLES

-Pantoprazole
-Rabeprazole
-Omeprazole
-Lansoprazole
-Esomeprazole

18

mechanism of proton pump inhibitors

in parietal cells, they are converted to their active form --> reacts with cysteine on H+/K+ ATPase --> form stable covalent bond --> irreversible inactivation of enyzme

19

clinical uses of proton pump inhibitors

-GERD, duodenal and gastric ulcers, multiple endocrine neoplasia 1 (MEN-1), Zollinger Ellison

-together with antibiotics help with H pylori infection

-NSAIDs induced ulcers: not only inhibit proton release but also they support platelet aggregation and maintain clot integrity (hemorrhagic ulcers usage)

20

adverse effects of proton pump inhibitors

- omeprazole inhibits metabolism of warfarin, clopidogrel, phenytoin, diazepam, cyclosporine

- decrease bioavailability of vit B12

- acid needed for absorption of digoxin and ketocanozole so decreased absorption of them

- long term use of omeprazole --> gastric carcinoid tumor

21

how do you diagnose H pylori infection

- endoscopic biopsy of ulcer margin
- serology test
- urea breath test

22

first line antimicrobials for H pylori eradication

CAMT
Clarithromycin
Amoxicillin
Metronidazole
Tetracycline

23

what are the mucosal protective agents

Mucosal MoBS

Misoprostol
Bismuth Subsalicylate
Sucralfate

24

mechanism of sucralfate

-binds to necrotic tissue and acts as a barrier to acid
-stimulates prostacyclin synthesis

25

when is sucralfate ineffective and why

with use of H2 receptor blocker or PPIs or antacids because it needs an acidic environment (low pH) to be activated

26

mechanism of bismuth subsalicylate

binds to ulcers and forms a coating and protects it from acid and pepsin

27

extra effects of bismuth subsalicylate

has some antimicrobial effects against H. pylori

28

mechanism of misoprostol

prostaglandin analogue (eicosanoid) that decreases acid secretion, stimulates mucin and bicarb secretion

29

clinical use of misoprostol

prevention of gastric ulcers induced by NSAIDS

30

adverse effects of misoprostol

DAE

-diarrhea
-abortion
-exacerbates IBD

31

cause of gastroesophageal reflux

abnormal relaxation of lower esophageal sphincter which allows acids from stomach to get to the esophagus

32

risk factors for gastroesophageal reflux

obesity, drugs, zollinger ellison, increased BMI

33

treatment of gastroesophageal reflux

-nonpharmacological: lose weight, don't drink acid rich drinks before bed, sleep with head elevated, small meals, stop smoking and drinking

-antacids: neutralize acid

-PPIs and H2 blockers

34

what are the prokinetic drugs

-Cholinomimetics: neostigmine, bethanechol
-5-HT agonists: metoclopramide, cisapride
-Macrolides: erythromycin

35

importance of prokinetic drugs

relieve GI symptoms of abdominal discomfort, bloating, heart burn, nausea, vomiting etc

36

mechanism of pro kinetic activity of metoclopramide

muscarinic activity via 5-HT4 receptor agonist activity

37

clinical use of metoclopramide

-diabetic, post op gastroparesis, and relief of symptoms of GERD
-nausea and vomiting for those on chemo

38

adverse effects of metoclopramide

anti dopaminergic

-sedation
-diarrhea
-Parkinsonian effects

39

mechanism of cisapride and use

5-HT4 agonist that stimulates ACh --> treatment of gastroparesis, GERD, constipation

40

adverse effect of cisapride

cardiac effects - arrhythmias

Decks in Pharmacology Class (79):