Question

Explain the mechanism of action of PPI and H2RA

Answer 1

Proton pump inhibitors (PPI) :-
Proton pump inhibitors are the group of medicines which acts on cell lines the stomach and reduces the production of HCL.
Mode of action of PPI:
Irreversibly blocks the hydrogen/ potassium adenosine triphosphatase enzyme system .
It is the last stage in gastric acid secretion. It is responsible for secretion of hydrogen ions in to the gastric lumen.
It irreversiblyblocks proton pump and there by stops HCL production. Due to irreversible nature of this inhibitors these medicines are more effective than H2 antagonists and it also reduces the secretion of gastric acid by 99 %.
Examples:
•   Omeprazole
•   Pantoprazole
•   Lansoprazole
•   Esomeprazole



H2RA:-
H2RA ( H2 receptor antagonists or H2 receptor blockers are the group of medicines which is used to treat the production of excess gastric acid.
These are used in treatment of gastritis and in peptic ulcers. And also used in GERD ( gastroesophageal reflux disease).

Mechanism of action : -
H2RA blocks the production of histamine in parietal cells of stomach. And decrease the acid production in these cells.
Examples:
•   Ranitidine
•   Nizatidine
•   Cimetidine
•   Famitidine