Modulation of excitatory amino acids pathway: a possible therapeutic approach to chronic daily headache associated with analgesic drugs abuse.

The use of antagonists of N-methyl-D-aspartate (NMDA) receptors, or the administration of inhibitors of the synthesis or of the release of excitatory amino acids, enables the analgesic drug-dependence associated with chronic daily migraine to be overcome without any physical abstinence sign. Follow-up period indicates that negative modulators of excitatory amino-acid function can induce a stable benefit. The persistent benefit is seemingly due to an inhibitory effect on the process underlying the hyperalgesia state which is a crucial feature of migraine. It can also be suggested that the antagonist activity at NMDA receptor might play a role in very severe non-opioid analgesic drug dependence.