Preliminary experience with Madopar HBS: clinical observations and plasma levodopa concentrations.

The therapeutic efficacy of Madopar HBS was investigated in 5 patients with advanced parkinsonism. They were under treatment with standard Madopar and suffered from marked fluctuations, mainly end-of-dose akinesia. All patients were abruptly switched from standard Madopar to the HBS formulation. For the first few days (up to 1 week) dosage and number of daily intakes of HBS were the same as those of the standard formulation. Under this treatment there was some deterioration of the clinical state. The dosage was then gradually increased, on average to about twice the daily amount. After 4 weeks therapy with Madopar HBS there was an improvement of akinesia and rigidity. End-of-dose akinesia was also improved, but all patients reported prolonged periods of early-morning akinesia; tremor remained unchanged. Hourly measurements of plasma levodopa and 3-O-methyldopa concentrations showed markedly increased values under Madopar HBS. The concentrations still were found to fluctuate in a similar extent as before and did not closely correlate with the actual stage of mobility. In contrast to the initial benefit, follow-up observation up to 40 weeks revealed a marked deterioration, either with permanent akinesia, or reappearance of fluctuations with a tendency from predictable to unpredictable forms.