Week 15 Reverse Cards Flashcards
Irreversibly inhibits the H+/K+-ATPase enzyme (proton pump) in gastric parietal cells to block the final step of acid secretion.
PPI Mechanism of Action
Lasts ~24 hours despite a short half-life due to irreversible binding to the proton pump.
PPI Duration of Action
Best taken 30–60 minutes before meals to coincide with active proton pumps.
PPI Administration Timing
First-line treatment for GERD, peptic ulcers, H. pylori eradication regimens, Zollinger-Ellison syndrome, and NSAID-induced ulcers.
PPI Clinical Uses
Long-term use may cause hypomagnesemia, vitamin B12 deficiency, fractures, pneumonia, and C. difficile infection.
PPI Adverse Effects
Metabolized by liver enzymes CYP2C19 and CYP3A4, which can cause drug interactions.
PPI Metabolism
Reversibly blocks histamine at H2 receptors on gastric parietal cells, reducing acid secretion.
H2 Blocker Mechanism of Action
Used for GERD, peptic ulcers, and stress ulcer prophylaxis, particularly in ICU patients.
H2 Blocker Uses
Dose adjustment required in patients with renal impairment due to renal excretion.
H2 Blocker Renal Considerations
May cause gynecomastia, galactorrhea, CNS effects in elderly, and CYP450 drug interactions.
Cimetidine Side Effects
Neutralizes existing gastric acid to provide rapid symptom relief.
Antacid Mechanism of Action
Diarrhea is a common side effect.
Magnesium Antacid Side Effect
May cause constipation.
Aluminum Antacid Side Effect
Can cause rebound acid secretion and gas.
Calcium Carbonate Antacid Side Effect
Provides short-term relief but does not heal ulcers or eradicate H. pylori.
Antacid Use Consideration
Prostaglandin E1 analog that reduces acid and increases mucus and bicarbonate secretion.
Misoprostol Mechanism of Action
Used to prevent NSAID-induced ulcers in high-risk patients.
Misoprostol Use
Contraindicated in pregnancy due to risk of uterine contractions.
Misoprostol Contraindication
Binds to ulcer base, forming a protective barrier without altering gastric pH.
Sucralfate Mechanism
Used as a mucosal protectant in peptic ulcer disease, often adjunctively.
Sucralfate Use
Blocks serotonin receptors in the GI tract and brain; used for chemo and post-op nausea.
5-HT3 Antagonists Mechanism
Ondansetron and granisetron.
5-HT3 Antagonists Examples
Used as antiemetics (e.g., promethazine, prochlorperazine) but may cause sedation and EPS.
Dopamine Antagonist Use
Dopamine antagonist with prokinetic and antiemetic properties; increases GI motility.
Metoclopramide Mechanism
