Pobilukast is the Leukotriene D4 receptor antagonist. Pobilukast significantly attenuated the Salmonella enteritidis endotoxin-induced thrombocytopenia but had no effect on either the endotoxin-induced early leukopenia or late leukocytosis. Additionally, Pobilukast significantly reduced the endotoxin-induced hemoconcentration and improved survival to 30% at 48 hr. Pobilukast dose-dependently inhibited the immediate hemodynamic changes after leukotriene D4 (LTD4) injections. Pobilukast also attenuated the increase in vascular permeability and the prolonged decrease in CO, suggesting that the observed cardiac and vascular effects of LTs were mediated by stimulation of LT receptors. A shift toward the right of the dose-response curves to histamine with pobilukast compared to that with placebo in three subjects was demonstrated, whereas the active compound did not exhibit any protective effect against histamine in the remaining nine subjects. It was concluded that there is a leukotriene component to the bronchial responses to histamine in some, but not all, subjects. Pobilukast had been in phase II clinical trial for the treatment of asthma. However, this development was discontinued.