In an open label study 63 patients with idiopathic Parkinson's disease suffering 
from end-of-dose akinesia were switched from a treatment with a L-DOPA standard 
formulation to a combined therapy of L-DOPA standard in the morning and L-DOPA 
slow release (levodopa, benserazide, Madopar Depot) at the remaining single 
doses. Substitution of L-DOPA standard by L-DOPA slow release took on average 
2-4 weeks. Patients were subsequently treated for 6 months. Due to a lower 
bioavailability of the slow release formulation--the latter is based on the 
"hydrodynamically balanced system" (HBS)--, the patients remained initially on 
their time schedule of drug intake but received a higher dose of L-DOPA slow 
release compared to the preceding L-DOPA standard therapy. In 20 centers 37 men 
and 26 women were included into the study. 27 males and 20 females completed the 
6 month treatment period. Before switching, the patients received 438 +/- 213 mg 
a day L-DOPA standard, after conversion, the average dose was 617 +/- 323 mg 
L-DOPA slow release and 107 +/- 95 mg L-DOPA standard a day. Fluctuations during 
the day and at night which were rated according to a newly developed clinical 
5-point rating scale were significantly improved by the treatment regimen from 
2.8 +/- 0.9 to 1.4 +/- 1.2. Additionally, parkinsonian symptoms were 
significantly reduced during the ON-phase as there was a significant decrease of 
the Webster rating score from 12.0 +/- 4.6 to 7.1 +/- 4.0. Quality of life as 
measured by subjective ratings of the patients improved. The tolerability of the 
new formulation of L-DOPA was rated to be good in 51.1% and very good in 48.9%. 
The results of this open label study suggest that the combination of L-DOPA 
standard in the morning and L-DOPA slow release formulation at the following 
time points can be an efficient therapy in parkinsonian patients who suffer form 
L-DOPA related end-of-dose motor akinesia.