Objects: to compare the efficacy of Sinemet CR4 (CR4), a slow release levodopa preparation, with that of standard Sinemet in patients with Parkinson's disease and motor fluctuations.
Methods: forty-five patients with Parkinson's disease of mild to moderate severity and motor fluctuations were entered into the 12 month trial. After a four week baseline period of optimal therapy, standard Sinemet was completely substituted by CR4 over 12 weeks, and clinical status monitored regularly over another 36 weeks. Evaluation was based on standard rating scales and patient's and physician's opinion ratings.
Results: forty-two patients completed the study. The mean optimum total daily dosage of Sinemet CR4 was 702 mg, significantly greater than the mean optimum daily dose of standard Sinemet--496 mg (p less than 0.01). Median number of doses per day was less, being 3 and 4 respectively (p less than 0.01). There was reduction in tremor (p less than 0.01) and rigidity (p less than 0.05) with Sinemet CR4 therapy compared with standard Sinemet, but no difference in disability scores, bradykinesia, gait, or postural instability. Twenty-five patients rated the change to Sinemet CR4 from standard Sinemet as "more helpful", 15 "about the same", and two "less helpful". There were no serious or unexpected adverse effects.
Conclusions: it was concluded that Sinemet CR4 was at least as effective as standard Sinemet, and it seemed particularly helpful in those patients with wearing-off who require frequent doses of standard Sinemet throughout the day.