Cimetidine—an Antifibrinolytic Agent?

The mucosal fibrinolytic activity was estimated in 14 patients with duodenal ulcer before and after 4 weeks' treatment with Cimetidine. A significant reduction in fibrinolytic activity in the corpus and antrum mucosa was found after treatment. In patients with healed ulcer after treatment, the activity was lower than in patients with unhealed ulcers, but no significance was proved. Similarly, in five patients with gastric ulcer, reduction in fibrinolytic activity was found after Cimetidine treatment but in the corpus mucosa only. The fibrinolytic activity in the mucosa is caused by plasmin. Whether this antifibrinolytic property of Cimetidine is of any importance in the treatment of ulcer disease is still unknown.