Introduction: Slow gastric emptying decreasing levodopa (LD) bioavailability contributes to motor fluctuations in Parkinson disease (PD). Melevodopa (LD methylester), ensuring rapid duodenal absorption, has been proposed as rescue therapy for afternoon off periods.
Objective: To assess daily motor fluctuations by multiple administrations of Sirio (Chiesi Farmaceutici SpA, Parma, Italy) (melevodopa/carbidopa) in PD patients.
Patients and methods: In this open-label naturalistic study, 75 PD patients (group A) completely switched standard LD (Sinemet or Madopar) with Sirio at an equivalent dosage (800-1000 mg/d). One hundred nineteen PD patients (group B) partially replaced their standard LD (Sinemet) with Sirio at an equivalent dosage (400-500 mg/d) while continuing Stalevo 100. In both groups, the observational period lasted 6 months. Assessments included an on/off diary, the Unified Parkinson's Disease Rating Scale (motor examination [UPDRS II] and activities of daily living [UPDRS III]), the dyskinesia scale, and an adverse event profile.
Results: Group A showed a significant reduction of afternoon off hours at 6 months (P < 0.05). Forty-five patients (69%) reported a subjective early onset of on motor response. Twelve patients (18.5%) reported its shorter duration. The dyskinesia scale score remained unchanged. Ten patients (13.3%) discontinued melevodopa for gastric intolerance. Group B showed at 6 months a significant reduction of total hours of daily off periods (P < 0.05), particularly in the morning (P < 0.01) and afternoon (P < 0.05). Seventy subjects (59%) expressed positive judgment on quickness of onset of on motor response. The dyskinesia scale score was unchanged. No significant adverse events were reported.
Conclusions: Switching PD patients with motor fluctuations to melevodopa, particularly in the presence of entacapone, could optimize critical periods of the day such as the morning delay on and afternoon off periods.