2005 Volume 51 Issue 2 Pages 257-262
Cetraxate hydrochloride (cetraxate), an antiulcer drug, produces a dose related increase in mucosal blood flow. We have reported that cetraxate increases plasma calcitonin gene-related peptide (CGRP) and substance P in healthy human subjects (J. Pharm. Pharmacol., 56, p. 557, 2004). Cetraxate is rapidly metabolized to tranexamic acid in plasma. We investigated the effect of tranexamic acid on human plasma CGRP, substance P, gastrin and somatostatin. Tranexamic acid at a dose of 500 mg or placebo was orally administered in five healthy male volunteers. The blood samples were taken before and at 20, 40, 60, 90, 120, 180 and 240 min after administrations, followed by the extracting procedure, and submitted to the high sensitive enzyme immunoassay system for CGRP and substance P as previously developed. Single administration of tranexamic acid caused significant increases of plasma CGRP concentration at 60-90 min compared with placebo, but the level-time profile was a little different from that of cetraxate. Tranexamic acid had no significant effect on plasma gastrin, somatostatin and substance P levels compared with placebo. In this study, we thought that the gastroprotective effect of cetraxate might not be due to plasma metabolite, tranexamic acid, but direct stimulation of gastric mucosa.