GI1 Flashcards Preview

Pharmacology Unit 6 > GI1 > Flashcards

Flashcards in GI1 Deck (26)
Loading flashcards...

In the stomach, parietal cells release:



Why would you give a GERD/ulcer patient an anticholinergic at bedtime?

prolonged reduction in acid secretion beyond the duration of a simple antacid


Which receptors is blocked by substituted benzimidazoles?

Remember these are the PPIs, so it is the H-K-ATPase on the lumenal surface of the parietal cell


Which drug is given as an ulcer treatment in RA patients? What is the rationale?

Misoprostol; since RA pts and others are on NSAIDs, ulcer risk is high, so replace prostaglandins with PGE2 analog


Which drug class is the only to primarily effect the lumenal rather than the basolateral surface of parietal cells?

PPIs: substituted benzimidazoles


Which class of antireflux/acid medications has rebound acidity after cessation of treatment?

H2 antagonists


What?s the worst thing about treating ulcers?

They come back!


What two layers overlay and are secreted by the superficial epithelial cells of the stomach lumen?

Mucus and bicarbonate layers


What three signaling molecules stimulate secretory activity by a parietal cell, and what drugs counteract them?

Histamine: H2 receptor antagonists
Acetylcholine: antimuscarinics
Gastrin: nothing?


What solution uses sucrose as a complexing agent with an antacid to bind ulcerated tissue at a healing rate comparable to H2 blockers? What is the antacid?

Sucralfate; aluminum hydroxide


What non-FDA approved treatment has a lower ulcer recurrence rate than H2 blockers?

Pepto Bismol (Bismuth) - crystals deposit in ulcers' acidic environment


What is the role of prostaglandins in parietal cell function? How is this altered by NSAIDs?

On H2 or ACH signaling, ATP generates active cAMP in the parietal cell. Prostaglandins block this process. Since NSAIDs (broadly) block prostaglandin activity, they allow unimpeded/unregulated signaling effects resulting in hypersecretion


What is the relationship between ulcer healing and acid suppression during the day?

The higher the percentage of the day in which you can suppress acid production, the shorter the time that an ulcer needs to heal


What is the preferred therapy for H pylori and associated ulcers?

2 regimens:
BID PPI/Ranitidine with 2 of [amoxicillin/ clarithromycin/ metronidazole]
BID PPI with TID/4ID tetracycline, bismuth, metronidazole


What is the pH goal of antacid therapy?

a pH of 5, reducing the proteolytic activity of pepsin


What is the MOA of an antacid?

Direct neutralization of hydrochloric acid in the stomach


What is the major direct effect of overtreating an over-secreting stomach with antacids?

Elevated absorption of the antacid:
Calcium bicarb - hypercalcemia
Al Hydroxide - excess Al, etc.


What is the 3-pronged approach to increasing the stomach's mucosal resistance?

Coat the ulcer (mechanical), increase mucous/bicarb secretions, and eradicate H pylori


What happens to bicarbonate production in a patient with gastric/duodenal ulcers?

It decreases


What drugs are ineffective to prevent ulcers if NSAIDs are on board?

H2 blockers and sucralfate; misoprostol is the only one approved


What are the 4 criteria to be met by ulcer treament, and in what 3 ways can it be accomplished?

1) Relieve symptoms (pain)
2) Promote healing
3) Prevent complications
4) Prevent recurrence

A) Neutralize acid
B) Decrease acid production
C) Increase mucosal resistance


What are the 2 anticholinergics used in GERD/Ulcers?

Atropine and Probantheline/Probanthine


List the PPIs in order of greatest CYP450 interaction to least. What is the practical result of this?

Greatest: Omeprazole, Lansoprazole, Rabeprazole, and Pantoprazole=Least (Dexlansoprazole is the odd one out, not sure why)
If a patient is on complex drug regimens, use pantoprazole


In the stomach, gastrin cells release ___ based on signals from the ___ nerve. The released hormone activates ___ cells.

1) Gastrin
2) Vagus
3) Parietal


Disruption of the mucosal blood flow (left gastric artery, submucous plexus, etc) is thought to have what effect?

Loss of the protective mucus layer overlying the region of impaired blood flow


Comparing antacids, H2 blockers, and PPIs, which 2 have comparable healing rates in duodenal ulcers?

antacids and H2 blockers; PPIs are superior