Duration of amantadine benefit on dyskinesia of severe Parkinson's disease.
BACKGROUND
Recent short-term studies suggested that amantadine (Ama) might ameliorate dyskinesia in patients with Parkinson's disease. A double-blind study programmed over 12 months was designed to assess the duration of the antidyskinetic effect of amantadine on levodopa induced dyskinesia.


METHODS
40 patients treated for 7.5 (2.2) years with levodopa (729.3 (199.4) mg/day) and dopaminoagonists, having peak dose or dyphasic dyskinesia with or without pain, were assessed with the Unified Parkinson's Disease Rating Scale subscale IV, Items 32-34, the Dyskinesia Rating Scale and Investigator Global Assessment. Twenty patients received amantadine chloridrate (100 mg) and 20 received a placebo. The Ama or placebo could be withdrawn when scores indicated worsening of dyskinesia, after agreement with the patient.


RESULTS
After 15 days of amantadine treatment there was a reduction by 45% in the total dyskinesia scores. All patients in the placebo group were withdrawn in 1-3 months and all patients in the Ama group were withdrawn in 3-8 months (p = 0.01, p<0.001). Ama withdrawal induced a rebound with increase of dyskinesia by 10-20% in 11 patients.


CONCLUSIONS
300 mg amantadine reduces dyskinesia in Parkinson's disease by approximately 45% but the benefit lasted less than eight months.
Thomas
A
A
Neurophysiopathology, Movement Disorders Centre, Department of Oncology and Neuroscience, Università G. D'Annunzio, Chieti-Pescara, Pescara, Italy.
Iacono
D
D
Luciano
A L
AL
Armellino
K
K
Di Iorio
A
A
Onofrj
M
M
D000368:Aged; D000547:Amantadine / Q000494:pharmacology* / Q000627:therapeutic use*; D015259:Dopamine Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D004311:Double-Blind Method; D020820:Dyskinesias / Q000188:drug therapy* / Q000209:etiology*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
D015259:Dopamine Agents; D007980:Levodopa; D000547:Amantadine