CPPene

Overview
CPPene is a potent competitive antagonist at the NMDA receptor. It was originally designed as a potential therapy for excitotoxicity, epilepsy or neuropathic pain. It looked very promising in in vitro trials proving to be a potent competitive antagonist at the NMDA without affecting other receptors. It's promise continued through to in vitro tissue culture studies where it proved to limit damage after occluding the middle cerebral artery leading to ischaemia. It also blocked photosensitive epilepsies in Baboons.

CPPene has a pharmacokinetic profile suitable of progressing to clinical trials as it has no toxic by products, is excreted exclusively via the renal system and remains unchanged in the brain.

However CPPene was removed from clinical trials as it provided no suitable neuronal protection or beneficial treatment for epilepsy. The reasons behind this is the relatively short therapeutic time window following ischaemic damage and a small amount of glutamate helps neuronal survival. It is also believed that some "pro-survival" genes are activated by NMDA receptors.

Possible directions for future development is via specific AMPA, Kainate of mGlu R subunits leading to more specific responses.