Hetrazepine PAF antagonists.

Hetrazepines such as WEB-2086 or WEB-2170 are potent, specific, competitive PAF antagonists binding at the same site as the PAF molecule. Despite their structural similarity to known hypnotic drugs they lack hypnotic actions. They almost certainly bind not only cell-surface but also intracellular PAF receptors, which may explain their activity in disease models in which adherence of neutrophils or other cell types to the vascular endothelium plays a role.