Table 3 Continuous dopamine receptor stimulation to prevent motor complications: clinical evidence from controlled trials in early PD patients

StrategyDrugsDuration of treatment (yr)Efficacy
Prolonged levodopa absorption16,17Levodopa/carbidopa CR5Failure
Levodopa/benserazide HBS5Failure
COMT inhibitionEntacaponeTo be tested
TolcaponeTrial interruptedTo be tested
MAO-B inhibition20Selegeline5Failure
Levodopa + dopamine agonist21Levodopa + bromocriptine5Effective
Direct dopamine-receptor stimulationPramipexole2–4Effective
(dopamine-agonist monotherapy)22-26Ropinirole5Effective
Cabergoline3–5Effective
Pergolide3Effective