A 23-year-old man with a long history of duodenal ulcer has been treated with cimetidine (Tagamet) for 6 months.
What is the mechanism of action of this drug?
A-Adds a protective membrane to gastric mucosa
B-Blocks H2 receptors
C-Stimulates H2 receptors
D-Inhibits H+,K+-ATPase
Answer
Cimetidine blocks H2 receptor so, it blocks the secretion of hydrochloric acid. It is H2 receptor antagonist. Proton pump inhibitors such as lansoprazole inhibit H+, K+ ATPase which inhibits acid secretion and has a long duration of action. Sucralfate works by adding a protective membrane to gastric mucosa. H2 receptor stimulators have a very adverse effect on gastric mucosa and they are contraindicated in this condition.
The correct answer is B