Pharmacokinetic comparison of Sinemet and Atamet (generic carbidopa/levodopa): a single-dose study

We compared the pharmacokinetic and motor responses of Sinemet and Atamet (generic carbidopa/levodopa) in patients with Parkinson's disease. Thirty Parkinson's disease patients (10 previously untreated, 10 with early disease, and 10 with motor fluctuations/dyskinesia) participated in a single-dose double-blind study. Following administration of an equivalent oral dose of Sinemet and Atamet on two separate days, we compared the peak plasma concentration, time to peak plasma concentration, area under the curve, total motor score, tapping score, and walking time. The mean time to peak plasma concentrations was 49 min with Sinemet and 47 min with Atamet, the mean peak plasma concentration was 1,273 ng/ml with Sinemet and 1,153 ng/ml with Atamet, and the mean area under the curve was 2,295 micrograms/ml/h with Sinemet and 2,330 micrograms/ml/h with Atamet. Similarly, there was no significant difference between total motor score, tapping score, or walking time. In this single-dose study, there were no significant differences in pharmacokinetic and motor responses between Sinemet and Atamet.