A randomized, double-blind, placebo-controlled, cross-over, multi-center study concerning the efficacy and safety of amantadine hydrochloride in treatment of dyskinesias in Parkinson's disease

INTERVENTION: An observation period (2 to 3 weeks) An administration of amantadine hydrochloride (27 days) A wash out period (15 days) An administration of placebo (27 days) An observation period (2 to 3 weeks) An administration of placebo (27 days) A wash out period (15 days) An administration of amantadine hydrochloride (27 days) CONDITION: Parkinson's disease PRIMARY OUTCOME: 1) UPDRS (parts 3 and 4) and Goetz score (measurements after amantadine hydrochloride and after placebo administration); 2) Incidence of adverse events SECONDARY OUTCOME: 1) Correlation between blood concentrations of amantadine hydrochloride and the UPDRS (parts 3 and 4) and Goetz score changes; 2) UPDRS (parts 3 and 4) and Goetz score changes stratified by the types of dyskinesias INCLUSION CRITERIA: Eligible patients are 20 to 75 years‐old, diagnosed as Parkinson disease (according to steps 1 and 2 of U.K. Parkinson's disease Society brain bank diagnostic criteria), and with dyskinesias of the limbs and the trunk