Metiamide: an antagonist of histamine-stimulated gastric acid secretion.

Metiamide, 25 mg, antagonized the action of histamine on acid and pepsin secretion from both denervated pouches and innervated stomachs in dogs. In the same preparations its action on pepsin following food, pentagastrin or 2 deoxy-d-glucose was nonsignificant. Following pilocarpine or secretin, metiamide augmented pouch pepsin. The action of every acid stimulant was depressed by metiamide including the direct vagal action of deoxy-d-glucose on the innervated stomach. H2 receptors seem, therefore, to be involved in some form in acid stimulated by the vagi, histamine, pentagastrin and pilocarpine. Pepsin stimulation does not seem to be via H2 receptors with the esception of stimulation by histamine itself.