Ethyl (3S,4aR,6S,8aR)-6-(4-ethoxycar- bonylimidazol-1-ylmethyl)decahydroiso-quinoline-3-carboxylic ester: a prodrug of a GluR5 kainate receptor antagonist active in two animal models of acute migraine.

Amino diacid 3, a highly selective competitive GluR5 kainate receptor antagonist, exhibited high GluR5 receptor affinity and selectivity over other glutamate receptors. Its diethyl ester prodrug 4 was orally active in two models of migraine:  the neurogenic dural plasma protein extravasation model and the nucleus caudalis c-fos expression model. These data suggest that a GluR5 kainate receptor antagonist might be an efficacious antimigraine therapy with a novel mechanism of action.