pharm - GI drugs Flashcards Preview

GI First half > pharm - GI drugs > Flashcards

Flashcards in pharm - GI drugs Deck (53)
Loading flashcards...
1

what stimulates chief cells ? result?

ACh, CCK, gastrin --> release of pepsinogen

2

prostaglandins in the stomach

are protective! stimulate mucous cell secretion (reduce inflammation)

vs rest of body where they cause inflammation

3

ECL cell secrete

histamine

4

major stimulatory mechanism for HCl secretion from parietal cells?

paracrine - histamine from ECL cells --> H2 receptor

5

imbalance between aggressive and defensive stomach mechanisms

peptic ulcer disease

6

antacids

neutralization of the HCl
4 --> aluminum hydroxide, magnesium hydroxide, calcium carbonate, and sodium bicarbonate

7

tums

sodium bicarbonate/ca carbonate
may increase gassiness and bloating due to CO2 product

8

antacids w effects on gastric motility

aluminum hydroxide --> DECREASE motility
magnesium hydroxide --> INCREASE motility
tums --> no effect

9

which antacid INCREASES gastric motility?

mg hydroxide

10

mucosal protective drugs

sucralfate (aluminum sucrose sulfate)
and
bismuth-subsalicylate

11

sucralfate

aluminum sucrose sulfate
forms a water insoluble viscous layer over ulcer tissue - maintenance therapy
**give on empty stomach!
-few side effects (constipation/dry mouth)

12

bismuth-subsalicylate

(pepto) does NOT neutralize acid --> binds to ulcer and
1) absorbs bile acids
2) stimulates mucous secretion
3) antibacterial effect on H pylori
**aspirin sensitive people might be sensitive
**turns stool black

13

what drug forms a viscous water insoluble layer over ulcer; non curative just maintenance

sucralfate

14

antimuscarinic agents?

dicyclomine and hycosamine

15

dicyclomine and hycosamine use?

antimuscarinic agents ----UNPLEASANT, bad side effects, rarely used to treat PUD

16

H2 receptor antagonists
and mechanism?

cimetidine, ranitidine
*used to treat ulcers
mech: structural analogs to histamine --> competitively inhibit histamine binding to H2 receptors
----REDUCE ACID SECRETION

17

Do H2 receptor antagonists have CNS side effects?

**they are hydrophilic so NO CNS side effects

18

H2 receptor antagonists have a ____ half life.
why is this not an issue?

short (2-3 hrs)

lack of significant side effects allow high/multiple dosages

19

which H2 receptor antagonist is the least ideal (most side effects)?
what are its negative effects?

cimetidine
-enhances prolactin and binds androgen receptos leading to gynecomastia, impotence and lactation issues
-inhbits cyt P450s --> prolongs half life of other drugs

20

PPIs

proton pump inhibitors - used to treat ulcers
omeprazole, esomeprazole, lansoprezole, pantoprazole
mech: inhibit the H K ATPase of gastric parietal cells with an irreversible covalent bond(kills the pump)

21

how PPIs get to the ATPase

prodrug as delayed release/enteric coated capsules--> absorbed as prodrug in duodenum --> circulation --> reaches parietal cell and is pumped into the acidic caniculi --> protonated by low pH --> active drug --> inactivates that same atpase

22

PPIs are most effective when...
how long is the effect?

-->taken 30-60 minbefore eating
when you are hungry the pumps begin pumping
they have half life of 1 hr, but since the ATPases are irreversibly inhibited, effect lasts days until new ones can be made

23

treatment of choice for zollinger ellison syndrome?

PPI
omeprazole

24

what is more effective for GERD: PPI or H2 antagonists?

PPI

25

do PPIs have CNS effects?

yes

26

PPIs side effects

*CNS, nausea, diarrhea
*prolonged suppression of acid secretion may increase c dificile colonization in stomach --> risk of pneumonia
*risk of spinal/hip fracture
*inhibits clopidrogel activation

27

Misoprostol

prostaglandin analog that inhibits gastric acid secretion and stimulates mucin secretion (protective just like PGE2)

28

why is misoprostol not used often?

1) PPIs are more effective and getting cheaper
2) potential abortifacient --> doesnt allow/aborts pregnancies

29

antimicrobial therapy for peptic ulcers

many ulcers have H pylori infection
Quadruple therapy - PPI + 2 antibiotics (tetracycline and metronidazole) + busmuth-subsalicylate
Concomittant therapy - PPI + 3 antibiotics (clarithromycin, metronadizole/tinidazole, and amoxicillin)

30

concommittant antimicrobial therapy

PPI + 3 antibiotics
(clarithromycin. amoxicillin, and metronidazole/tinidazole)