Randomized Double-Blind Cross-Over Study of Sinemet-Controlled Release (CR4 50/200) versus Sinemet 25/100 in Parkinson’s Disease

Sinemet-controlled release (CR4) consisting of 50 mg carbidopa/200 mg levodopa was compared with Sinemet 25/100 in 24 Parkinson's disease (PD) patients during a 16-week double-blind cross-over study. The mean age of the patients was 66.2 years, their mean duration of PD was 9.3 years. All of the patients had response fluctuations consisting mainly of the 'wearing-off' phenomenon. Some of the patients also experienced the 'on-off' phenomenon. All patients were evaluated using the unified Parkinson disease rating scale. The following significant differences were noted on Sinemet CR4. More patients noted a decrease in dyskinesias and response fluctuations; more patients experienced a decrease in stage when 'on'; more patients were 'on' longer during the day, and more patients were globally improved. The mean number of doses per day were significantly less on Sinemet CR4 (mean 5.0, range 3–8) than on Sinemet 25/100 (mean 6.2, range 4–11 doses/day). The mean dose of levodopa in Sinemet CR4 was 1,186 ± 458 mg and the mean dose of carbidopa was 797 ± 115 mg. The mean dose of levodopa in Sinemet 25/100 was 873 ± 304 mg and the mean dose of carbidopa was 218 ± 76 mg. This study indicates that Sinemet CR4 is a useful addition for patients with response fluctuations.