The wearing-off phenomenon in Parkinson's disease refers to the recurrence of motor and non-motor symptoms before the next scheduled dose of levodopa.
Patient selection: Parkinson's disease on levodopa therapy
Risk factors for wearing-off phenomenon:
(1) earlier age at the onset of Parkinson's disease (age < 60 years)
(2) longer disease duration (7.9 years +/- 5.1 vs 5.6 +/- 3.1)
(3) longer duration of therapy with anti-Parkinsonian therapy (7.2 years +/- 5.1 vs 3.9 +/- 3.5)
(4) longer duration on levodopa treatment (6.9 +/- 4.9 vs 3.1 +/- 2.8)
It is important to exclude other explanations for the symptoms such as cerebrovascular disease or drug effect.
If the wearing-off phenomenon is identified then therapy is modified, which may involve:
(1) more frequent dosing of levodopa
(2) sustained release formulation
(3) addition of another agent
