dextrorphan and Parkinson-Disease

In animal models of Parkinson's disease (PD), glutamate antagonists diminish levodopa (LD)-associated motor fluctuations and dyskinesias. We sought to investigate if these preclinical observations can be extended to the human disease, by evaluating the effects of three non-competitive NMDA antagonists (dextrorphan, dextromethorphan and amantadine) on the motor response to LD in patients with advanced PD. In four separate trials, adjuvant therapy with these drugs reduced LD-induced dyskinesias and motor fluctuations. These findings support the view that drugs acting to inhibit glutamatergic transmission at the NMDA receptor can ameliorate LD associated motor response complications.

Topics: Amantadine; Clinical Trials as Topic; Controlled Clinical Trials as Topic; Dextromethorphan; Dextrorphan; Excitatory Amino Acid Antagonists; Glutamic Acid; Humans; Levodopa; Movement Disorders; Parkinson Disease; Psychomotor Performance; Receptors, N-Methyl-D-Aspartate

Topics: Dextrorphan; Double-Blind Method; Drug Therapy, Combination; Excitatory Amino Acid Antagonists; Humans; Levodopa; Middle Aged; Movement Disorders; Parkinson Disease; Placebos; Severity of Illness Index