Pharmacology MCQs- 206

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


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

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