Slower progression of Parkinson's disease with ropinirole versus levodopa: The REAL-PET study.
Preclinical studies suggest ropinirole (a D2/D3 dopamine agonist) may be neuroprotective in Parkinson's disease (PD), and a pilot clinical study using (18)F-dopa positron emission tomography (PET) suggested a slower loss of striatal dopamine storage with ropinirole compared with levodopa. This prospective, 2-year, randomized, double-blind, multinational study compared the rates of loss of dopamine-terminal function in de novo patients with clinical and (18)F-dopa PET evidence of early PD, randomized 1 to 1 to receive either ropinirole or levodopa. The primary outcome measure was reduction in putamen (18)F-dopa uptake (Ki) between baseline and 2-year PET. Of 186, 162 randomized patients were eligible for analysis. A blinded, central, region-of-interest analysis showed a significantly lower reduction (p = 0.022) in putamen Ki over 2 years with ropinirole (-13.4%; n = 68) compared with levodopa (-20.3%; n = 59; 95% confidence interval [CI], 0.65-13.06). Statistical parametric mapping localized lesser reductions in (18)F-dopa uptake in the putamen and substantia nigra with ropinirole. The greatest Ki decrease in each group was in the putamen (ropinirole, -14.1%; levodopa, -22.9%; 95% CI, 4.24-13.3), but the decrease was significantly lower with ropinirole compared with levodopa (p < 0.001). Ropinirole is associated with slower progression of PD than levodopa as assessed by (18)F-dopa PET.
Whone
Alan L
AL
Faculty of Medicine, Imperial College, Hammersmith Hospital, London, United Kingdom.
Watts
Ray L
RL
Stoessl
A Jon
AJ
Davis
Margaret
M
Reske
Sven
S
Nahmias
Claude
C
Lang
Anthony E
AE
Rascol
Olivier
O
Ribeiro
Maria J
MJ
Remy
Philippe
P
Poewe
Werner H
WH
Hauser
Robert A
RA
Brooks
David J
DJ
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism; D018450:Disease Progression; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics; D006801:Humans; D007211:Indoles / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D007980:Levodopa / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D011446:Prospective Studies; D011699:Putamen / Q000000981:diagnostic imaging / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000187:drug effects*; D012720:Severity of Illness Index; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000378:metabolism; D014055:Tomography, Emission-Computed
D018491:Dopamine Agonists; D005462:Fluorine Radioisotopes; D007211:Indoles; D017448:Receptors, Dopamine D2; C046649:ropinirole; D007980:Levodopa; D004298:Dopamine