FRG8701 is a new Histamine H2-receptor antagonist with an IC50 of ranging from 0.25 to 0.43 μM.

The inhibitory potency of FRG8701 is almost the same as that of famotidine and approximately 33 times greater than that of cimetidine.Positive chronotropic response to histamine at 10-5 M is dose dependently inhibited by FRG8701 (FRG-8701) famotidine or cimetidine;?and the IC50 values of FRG8701, famotidine and cimetidine are 3.3, 3.0 and 108.6 (×10-7M), respectively.

FRG8701 effectively inhibits the formation of gastric lesions induced by various necrotizing agents, demonstrating its protective effects on the gastrointestinal tract. Oral administration of FRG8701 produces a dose-dependent reduction in the development of gastric lesions caused by stress, indomethacin, and the formation of duodenal ulcers due to mepirizole, with ED50 values ranging from 1.1 to 9.4 mg/kg for gastric lesions and 1.7 to 6.9 mg/kg for each ulcer model. Additionally, in pylorus-ligated rats, intraduodenal delivery of FRG8701 dose-dependently decreases total acid output. Furthermore, FRG8701, whether administered orally or intraperitoneally at doses of 10 or 30 mg/kg, significantly prevents gastric mucosal lesions induced by 0.4 N HCl+50% ethanol, underscoring its potential as a protective agent against gastrointestinal damage.