Controlled-release levodopa/carbidopa. III: Sinemet CR5 treatment of response fluctuations in Parkinson's disease.

Five patients with advanced Parkinson's disease and fluctuations in therapeutic response to levodopa participated in, and four completed, an open label study of the efficacy of Sinemet CR5. Reductions in the number of daily doses and "off" periods as well as the increase in interdose interval and percent "on" time versus standard Sinemet were comparable to those achieved with Sinemet CR4 in these same patients. As compared with Sinemet CR4, there was a greater delay in the occurrence of peak plasma levodopa concentrations, and relative bioavailability was reduced. Sinemet CR5 appears to offer no advantages over Sinemet CR4 in the treatment of response fluctuations in Parkinson's disease.