Compare and contrast the pharmacology of ranitidine and omeprazole.
College Answer
These agents are both commonly used in the ICU. The expectation was weighted towards the
interesting and important aspects of pharmacology as outlined for category B drugs.
It was expected candidates could detail that both drugs are used to suppress acid secretion in
the stomach. Ranitidine is a competitive, reversible inhibitor of the action of histamine at the
histamine H2 receptors found in gastric parietal cells. This results in decreased gastric acid
secretion and gastric volume, and reduced hydrogen ion concentration.
In contrast to Omeprazole which is a proton pump inhibitor that irreversibly blocks
the hydrogen potassium ATPase the gastric parietal cells.
Some general description of dosing, route of administration, pharmacokinetics and possible
adverse effects was expected.