Anti Ulcer Drugs Fitz Flashcards
What is the most effective drug for preventing and treating peptic ulcer disease?
ANTIMICROBIALS because the eradicate H. pylori
Why is amoxicillin the best drug in its class?
Broad spectrum- treats gram neg
Good oral bioavailability
Acid Stable
Why is clarithromycin the best macrolide choice to treat H. pylori?
It has a substantially LOWER MIC90!!! (you want it to be low NOT high!!!)
More acid stable, and fewer SE
Why is should you NOT give antacids with tetracycline?
Significantly decreases antibiotic efficacy due to chelation
What is the most effective agents for reducing intragastric acidity? Why?
PPIs
the IRREVERSIBLY inhibit the final common pathway in acid secretion: H/K ATPase
Which H2 receptor blocker has the most side effects?
Cimetidine
How to H2 receptors work?
Decrease all forms of gastric acid secretion (esp nocturnal)
How do antacids work in general?
They are weak bases used to buffer stomach acid
Which drugs are useful for intermittent dyspepsia?
Antacids
Rapid onset short duration
No prevention of ulcer recurrence
What is the drug of choice for Zollinger-Ellison Syndrome, GERD, and ulcer treatment?
PPIs
Slow onset
Long duration
Excellent Prevention of ulcers
Sucralfate
Attaches to BM of ulcer, stimulates PG and HCO3 secretion, recruits growth factors for repair
**requires acid environment to be active (don’t give with PPI, H2 blocker, etc)
Two MOAs for Bismuth Subsalicylate?
Direct antimicrobial against H. pylori (disrupts cell wall, prevents adhesion, inhibits urease)
Protects ulcer surface- coats to protect and stimulates PG
What is the drug of choice for treatment of ulcers induced by NSAIDS?
MISOPROSTOL (PGE1)
Omperazole Esomerprazole Lansoprazole Pantoprazole Raberprazole
PPIs
Atropine
Pirenzipine
Antimuscarinics
Cimetidine
Ranitidine
Nizatidine
Famotidine
Antihistamines - H2 receptor blockers
MOA Rifabutin?
Static or cidal?
Inhibts DNA dependent RNA polymerase
Bactericidal!
Drug that inhibits CYP3A4 ?
Clarithromycin (macrolides)
Drug that induces CYP450?
Rifabutin
**Ramps up cyp450
Drug that inhibits CYP2c9?
Why is this important?
Metronidazole
Because CYP2c9 metabolizes Warfarin. So blocking it, potentiates Warfarin and can increase ulcer bleeding!
Bismuth subsalicylate does 2 things, what are they?
In one of its roles, it increases the production of what 3 things?
Antimicrobial (disrupts cell wall, prevents adhesion)
Protects surface
In its role as a surface protector: it increases secretion of mucus, prostaglandins, and bicarbonate
Potential side effects of salicylate?
Tinnitus Vomiting Metabolic acidosis Confusion Hyperthermia
Why are muscarinic antagonists rarely used to treat ulcers?
Slow gastric emptying…prolong exposure of ulcer to acid
What receptor does ACh bind on ECL cells?
M1
What receptor does ACh bind on parietal cells?
M3
ABCD’S of anticholinergic side effects?
Anorexia blurry vision constipation/confusion dry mouth stasis or urin/sedation
Secondary effect of H2 antagonists?
Decrease cAMP…decrease basal acid secretion and nocturnal secretion and meal time secretion
What drugs can cause bradycardia and hypotension if given IV rapidly?
H2 antagonists
What are 2 major things to know about Cimetidine?
At high doses: can cause gynecomastia and impotence in males and galactorrhea (excessive milk production) in females because of decreased estrogen metabolism and increased prolactin
Inhibits CYP450 so it increases the effectiveness of drugs metabolized by it.
What do you use for sx relief of stress induced ulcers in ICU?
Sucralfate
*liquid bandaid
What kind of environment does sucralfate need?
ACID! Don’t give with PPI or H2 blocker or antacid
