5-Hydroxy-tryptophan for the treatment of l-DOPA-induced dyskinesia in the rat Parkinson's disease model

Importantly, the antidyskinetic effect of 5-HTP 24 mg/kg does not appear to be due to a competition with l-DOPA for crossing the blood-brain barrier; in fact, similar l-DOPA striatal levels were found in l-DOPA only and l-DOPA plus 5-HTP 24 mg/kg treated animals. These data further confirm the involvement of the serotonin system in the appearance of LID, and suggest that 5-HTP may be useful to counteract the appearance of dyskinesia in Parkinson's disease patients.