Biochem/physiol Actions

BIBN4096BS (Olcegepant) is a potent calcitonin gene-related peptide (CGRP) receptor antagonist with higher affinity/potency toward human over rat & mouse receptor (human/rat Ki = 14.4 pM/3.4 nM by binding assay; human/mouse Kb = 8 pM//7.711 nM by cellular cAMP assay). BIBN4096BS inhibits facial blood flow by electrical stimulation of marmoset monkey trigeminal ganglion (IC50 = 3 µg/kg i.v.) without any intrinsic cardiovascular effects. Studies using anaesthetized rats reveals that BIBN4096BS antagonism against trigeminal nociceptive stimulation by capsaicin is limited to the spinal trigeminal nucleus, but not trigeminal ganglion. Also widely employed for in vivo studies in mice.