Drugs Used in GI Dysfunction Flashcards
What are the important H2 antagonists used in the treatment of stomach dysfunction? Suffix?
“itidine”
Cimetidine, Ranitidine, Famotidine
What is the MOA of cimetidine?
suppress secretary responses to food stimulation by indirectly inhibiting the actions of the proton pump
also, partially antagonizes HCl secretion caused by vagal or gastrin induced release of histamine from ECL like cells
Uses of H2 antagonists?
PUD
Gastroesophageal reflux disease (GERD)
Zollinger-Ellison syndrome
What are the S/E of cimetidine?
similar to azoles
blocks P450> dec androgens> gynecomastia and decreased libido
Name the PPIs? Suffix?
“prazoles”
Omeprazole
MOA of PPIs?
direct inhibitors of the proton pump (K+/H+) anti port in the gastric parietal cell
What are the uses for PPIs?
Effective in GERD and Zollinger Ellison syndrome
Eradication regimen for H.pylori
Which is more effective in treating gastric ulcers? PPIs or H2 antagonists?
PPIs
What is the MOA of misoprostol?
PGE1 analog which is cytoprotective > mucus and bicarbonate secretion and dec HCl secretion
What is the MOA of sucralfate?
polymerizes on GI luminal surface to form a protective gel-like coating of ulcer beds (requires acidic pH)
What are the uses of sucralfate?
improve healing and decrease ulcer recurrence
MOA bismuth subsalicylate?
Like sucralfate binds selectively to ulcer, coating it and protecting it from acid and pepsin
Use of Bismuth subsalicylate as a triple therapy? Which drugs is it commonly used with?
combined with metronidazole and tetracylcline (BMT) regimen to eradicate H pylori
Name the antacids?
Al (OH)3 aluminum hydroxide, Mg(OH)2 magnesium hydroxide, CaCO3 calcium carbonate
S/E of antacids?
constipation (Al+++), diarrhea (Mg++) rebound hyperacidity
What are some receptors in the CTZ targeted for antiemetic effects ?
D2
5HT3
CB1
Describe the absorption of antacids with quinidine?
quinidine is a weak base so oral absorption would increase
Describe absorption of antacids with tetracyclines?
tetracylines chelate polyvalent cations so it would decrease absorption
Describe the dual action opioids have on emesis?
opioids dec emesis by activating receptors that dec. pain transmission and inc. emesis by activating receptors in the CTZ
What are the 5HT3 antagonists? Suffix?
“setrons”
ondansetron
What DA antagonists are used for emesis? Do they have other indications?
prochlorperazine, metoclopramide
Also used in cancer chemotherapy; also pro kinetic in GERD
Cannaboids used for anti emetic action?
dronabinol
NK1 receptor antagonists work?
NK1 receptors act by releasing substance P and concurrently activate vomiting center so you are blocking this pathway
How does mesalamine work to treat CD and UC?
(5-ASA) acts as anti- inflammatory agent
What are some immunosuprressive agents used for moderate to severe CD and UC?
corticosteroids, cyclosporine, anti-TNF alpha drugs
