Development and progression of motor fluctuations and side effects in Parkinson's disease: comparison of Sinemet CR versus carbidopa/levodopa.

We compared the chronic (2-year) effect of substitution with Sinemet CR with the effect of continued administration of standard Sinemet on motor fluctuations and drug-induced side effects in Parkinson's disease (PD). Twelve patients in each treatment group were pair-matched for age, PD duration, duration of levodopa therapy, dosage of Sinemet, PD disability, and side-effect prevalence at study entry. After 2 years, both groups were more disabled from their PD than at baseline; the disability scores were equivalent for the 2 treatments. The Sinemet CR group had fewer fluctuations and fewer side effects. Compared with the standard Sinemet group, Sinemet CR patients had more "on" time (mean 83% versus 62%, p less than 0.001), and had a lower prevalence of disabling chorea (p less than 0.007), dystonia (p less than 0.003) and sleep disruption (p less than 0.002). Prevalence of hallucinations was equivalent for the 2 groups. These results suggest that Sinemet CR is beneficial in ameliorating and preventing the high frequency of some side effects of standard Sinemet treatment.