Upper GI pharm [3] Flashcards Preview

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Flashcards in Upper GI pharm [3] Deck (18):
1

PPI
- Class
- MOA

Antisecretory/cytoprotective agent
inhibits H-K-ATPase in parietal (oxyntic) cell

2

Uses of PPI (what diseases)

GERD (most effective)
Peptic ulcer disease (faster relief than H2 antag)
NSAID induced (preferred)
Stress gastritis (preventive)
ZE syndrome

3

H2 antagonist
- class
- MOA

Antisecretory/cytoprotective agent
competitive reversible block of H2 receptors on BASOLATERAL membrane

- less effective than PPIs + more rapid onset of action than PPI in acute gastritis

4

Uses of H2 antagonist
[Ranitidine, cimetidine]

GERD
PUD (but mainly PPI)
Stress related gastritis

5

Misoprostal

PG agonist that acts on epithelial cell to decrease H+ secretion and increase mucus bicarb

- uses: NSAID induced ulcers

6

Side effects of PPI
[omeprazole, lansoprazole]

mild: headache, abdominal pain, nausea, constipation, diarrhea
HYPER-gastrinemia (w/ chronic PPI use)
- like pseudo ZE!

7

DDI of PPI
[omeprazole, lansoprazole]

act on CYP450
- omeprazole can inhibit conversion of antiplatelet agent clopidogrel to active form

8

H2 receptor antagonist side effects
[omeprazole, lansoprazole]

gynecomastia
dosage reduction in renal dysfxn

9

DDI of H2 receptor antagonist
[omeprazole, lansoprazole]

Cimetidine inhibits CYP450 oxidative metabolism → increase toxicity of some drugs (warfarin, phenytoin, carbamazepine, BDZ)

10

All antisecretory agents decrease _______ absorption → ______

ketoconazole
increase gastric pH

11

actions of proton pump inhibitors and prostaglandins in protecting the gastrointestinal tissues

PPI: prodrug → get into circulation → activated in parietal cells
- only inactivates active pumps

Prostaglandin analog
inhibit cAMP in parietal cells → decrease H+ and stimulate neutralizing HCO3- formation and cytoprotective mucus formation
- CONTRAINDICATED IN PREGGOS

12

Ideal antacid should:
rapidly raise pH of stomach contents to _____
Absorbable or nonabsorbable?
short or long acting?

4-5 (but if 7 can lead to rebound acid secretion)
be nonabsorbable
long acting

and have NO undesirable side effects
- can use Mg [diarrhea] with Al or Ca [constipation] to counteract each others effects

13

Primary ingredients in antacids

Calcium → constipation + hypercalcemia
Aluminum → constipation + CNS toxicity
Magnesium → osmotic diarrhea + exacerbate renal dis
NaHCO3 → potent but contraindicated for systemic effects + pregnancy

14

Prokinetic agents
[metoclopramide]
- MOA
- tx for?

directly or indirectly increase agonist activity at smooth muscle M3 receptors
- bowel motility (achalasia, gastoparesis)
- Esophagitis associated with GERD

(note that metoclopramide is an antagonist at D2 to inhibit the release of ACh, which leaves less to act on M3)
- increase coordinated contraction → enhance transit

15

Antiemetic agent: 5HT3 receptor antagonist
[ondansetron]
- MOA

block 5HT3 receptors at chemoreceptor trigger zone (CTZ)

- prevention in use of cytotoxic drugs, opioid analgesics

16

Antiemetic agent: 5HT3 receptor antagonist
[ondansetron]
- side effects

constipation
increase dose → increase QT

- safe in pregnancy vomiting/nausea!!!!! yay

17

Antiemetic agent: D2 receptor antagonist
[metoclopramide]
- MOA

block DA receptors at CTZ

- use for nausea/vomiting of chemotherapy
- effective in n/v for pregnancy!!! (just like 5HT3 R antag)

18

Antiemetic agent: D2 receptor antagonist
[metoclopramide]
- side effects

Extrapyramidal side effects