Dexanabinol: a novel cannabinoid with neuroprotective properties.

Dexanabinol was developed as a synthetic analog of the cannabinoid tetrahydrocannabinol, however, the action of the drug is as a weak, uncompetitive antagonist at the N-methyl-D-aspartate (NMDA) receptor. Dexanabinol is an effective neuroprotectant in animal models of hypoxemia/ischemia, neurotoxin exposure and nerve crush. Unlike some other uncompetitive NMDA receptor antagonists, dexanabinol does not produce psychotrophic effects and is generally well tolerated in humans. In this respect it is similar to the uncompetitive NMDA receptor antagonist memantine. Dexanabinol is currently in phase III clinical trials for severe head injury. It is a promising drug that appears to be able to provide the therapeutic benefits of uncompetitive NMDA-receptor antagonists without the adverse side effects associated with some of the earlier drugs of this type.