Ebrotidine

Ebrotidine (FI 3542) is a competitive H2-receptor antagonist (Ki= 127.5 nM) with a potent antisecretory activity and evidenced gastroprotection. IC50 Value: 127.5 nM (Ki) [1]; 0.21mg/kg (ED50, histamine- stimulated acid secretion) [2] Target: H2 receptor in vitro: Ebrotidine displaced 3H-thiotidine specific binding to histamine H2-receptors (Ki: 127.5 nmol/l), showing a higher affinity (p < 0.05) than ranitidine (Ki: 190.0 nmol/l) and cimetidine (Ki: 246.1 nmol/l) [1]. in vivo: Following intravenous administration to rats, ebrotidine inhibited histamine- and pentagastrin-stimulated acid secretion in a dose-dependent manner, ED50 being 0.21 and 0.44 mg/kg, respectively [2]. The mean number of gastric erosions seen at endoscopy after treatment with ebrotidine plus ASA (2.0 +/- 0.3) was significantly lower than that after placebo plus ASA (3.7 +/- 0.2) . This reduction in lesion core by ebrotidine was accompanied by a significant increase in gastric blood flow (by 15% in corpus and 26% in antrum), by a rise in transmucosal potential difference (by 12%), and by a decrease of mucosal microbleeding [3]. Results of macroscopic assessment revealed that ebrotidine at doses of 50mg and higher/kg body weight effectively prevented mucosal injury, and that the maximal protective effect was achieved by 1h. Physicochemical analysis established that ebrotidine evoked 30% increase in mucus gel dimension, and showed 20% increase in phospholipids, and the content of sulfo- (18%) and sialomucins (21%) [4].