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.