Proton Pump Inhibitors Flashcards
What is the ROA of all the H2 antagonists and PPIs?
Oral
What are the signs of GERD?
Heartburn, regurgitation, vomiting and pain on swallowing
Antacid MOA
Stomach acid is neutralized briefly after each dose
Antacid SE
Ingestion of large amounts of calcium and adsorbable alkali can lead to hypercalcemia, alkalosis and
renal impairment, a constellation known as milk-alkali syndrome
Histamine Antagonist MOA
Reduce production of acid in the stomach by H2 receptor antagonism
Histamine Antagonist SE
Very safe - rare SE of renal and hepatic toxicity
Do H2 antagonists cross the BBB? Placenta?
Cross the blood-brain and placental barriers
Proton Pump Inhibitor MOA
Effectively block acid secretion by irreversibly binding to and inhibiting the H-K ATPase pump that resides on the luminal surface of the parietal cell membrane.
What is the molecular mechanism of the PPIs action?
- They are weak bases concentrated in the acid
compartment of parietal cells - The inactive prodrug is activated in the acid environment
- A reactive sulfhydryl group then forms a disulfide bond with cysteine residue on the H- K-ATPase pump, thereby inactivating the enzyme
Why shouldn’t H2 antagonists be given with PPIs?
H2 antagonists should not be given simultaneously with PPIs, because the antagonists reduce the efficacy of the PPIs
What are PPIs the drug of choice for?
They are of the drug of choice for treatment of Zollinger-Ellison syndrome and GERD when not responsive to H2 antagonists
What are the drug interactions of PPIs?
PPIs are metabolized by CYP450 and therefore can decrease the metabolism and clearance of benzodiazopines, warfarin and phenytoin
What vitamin can PPIs inhibit the absorption of?
Vitamin B12
PPI SE
Mild. Include diarrhea, headache, drowsiness, muscle pain and constipation.
Mucosal Protective Agent MOA
It is thought to polymerize and bind electively to necrotic tissue, creating a barrier between the gastric contents and the mucosa
