Rupatadine D4 fumarate (UR-12592 D4 fumarate) is a deuterium labeled Rupatadine fumarate. Rupatadine Fumarate (UR-12592 Fumarate) is a potent dual PAF/H1 antagonist with Ki of 0.55/0.1 μM(rabbit platelet membranes/guinea pig cerebellum membranes)[1][2][3].
[1]. Merlos M, et al. Rupatadine, a new potent, orally active dual antagonist of histamine and platelet-activating factor (PAF). J Pharmacol Exp Ther. 1997 Jan;280(1):114-21. [2]. Queralt M, et al. In vitro inhibitory effect of rupatadine on histamine and TNF-alpha release from dispersed canine skin mast cells and the human mast cell line HMC-1. Inflamm Res. 2000 Jul;49(7):355-60. [3]. Lv XX, et al. Rupatadine protects against pulmonary fibrosis by attenuating PAF-mediated senescence in rodents. PLoS One. 2013 Jul 15;8(7):e68631.