Anti-ulcer drugs, histamine-2 receptor

A series of anti-ulcer drugs such as cimetidine and ranitidine were the most successful drugs of all time when they first appeared. They work by inhibiting histamine action in the stomach. We shall look at a more modern version, a drug from what was then SmithKline Beecham, another H2 receptor histamine antagonist24 202. It is particularly appropriate for this chapter as it contains three heterocyclic rings with two heteroatoms each an imidazole, a pyrimidone, and a thiazole and it allows us to revise material from other chapters as well as this. 

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