Double-blind comparison of standard Sinemet and Sinemet CR in patients with mild-to-moderate Parkinson's disease.

The combination of carbidopa and levodopa (Sinemet) is a highly effective treatment for the symptoms of Parkinson's disease. However, side effects, such as abnormal involuntary movements, fluctuations in motor performance, and "wearing off" phenomena limit its long-term usefulness in some patients. Open-label studies show that controlled-release Sinemet CR is effective in reducing motor fluctuations. This report discusses the results of a 14-week double-blind crossover study comparing the efficacy and tolerability of standard Sinemet with controlled-release Sinemet CR. Overall, there were no statistically significant differences in efficacy between Sinemet CR and standard Sinemet on any of the major efficacy measures, suggesting a clinical equivalence in terms of treating the symptoms of Parkinson's disease. The study also supports the tolerability of Sinemet CR. In summary, Sinemet CR holds the promise of reducing some disturbing side effects of long-term levodopa therapy, thus achieving optimal control of parkinsonian symptoms.