Amantadine for dyskinesia in patients affected by severe Parkinson's disease.

20 patients (12 men and 8 women, mean age 65 years) affected by severe Parkinson's disease (PD) with peak-dose and/or diphasic dyskinesias or painful dyskinesia were treated with amantadine (300 mg/day) as adjunctive therapy to current levodopa, carbidopa and dopaminoagonist. UPDRS (Unified Parkinson's disease rating scale), dyskinesias rating scale (DRS) and IGA (investigator global assessment) scale were used to evaluate the severity of PD symptoms during follow-up. After 15 days with amantadine treatment all patients improved with an average 38% reduction in dyskinesias (p<0.001). After 2-8 months. amantadine was withdrawn in all patients. After amantadine withdrawal, 2 patients experienced severe hyperthermia (39 degrees C and 40 degrees C). No difference was found between end of treatment dyskinesia scores and final withdrawal scores (p<0.5). In the two patients with hyperthemia amantadine was reintroduced; after four days hyperthermia subsided and amantadine was finally tapered over 15 days without further adverse reactions.