Investigation of the impact of sarizotan on the pharmacokinetics of levodopa.
OBJECTIVE
To investigate the effect of sarizotan on the pharmacokinetics of levodopa in fixed combination with carbidopa or benserazide.


METHODS
In this open-label, randomized, crossover study, healthy male subjects (n=16) received levodopa 100 mg t.i.d. over two 5-day periods, alone or in combination with sarizotan 5 mg b.i.d. Levodopa was administered with a dopa-decarboxylase inhibitor (carbidopa 25 mg, n=8 or benserazide 25 mg, n=8). Pharmacokinetic parameters of levodopa were obtained on days 1 and 5.


RESULTS
ANOVA showed the C(max) values for levodopa were not significantly different with or without sarizotan after single doses (1001 vs 1082 ng/ml; point estimate [PE] 1.10, 90% confidence intervals [CI] 0.83-1.45) or at steady-state (1549 vs 1663 ng/ml; PE 1.06, 90% CI 0.89-1.27); nor were AUC values for single doses (1661 vs 1665 ng h/ml; PE 1.01, 90% CI 0.91-1.11) or at steady-state (2462 vs 2482 ng h/ml; PE 1.01, 90% CI 0.97-1.05). Seven subjects reported adverse events of mild-to-moderate intensity; the most frequent were headaches and dizziness.


CONCLUSIONS
Coadministration of sarizotan with levodopa, in combination with a dopa-decarboxylase inhibitor had no effect on the pharmacokinetics or adverse event profile of levodopa.
Krösser
Sonja
S
Department of Clinical Pharmacology and Pharmacokinetics, Merck KGaA, Darmstadt, Germany. Sonja.Kroesser@merck.de
Neugebauer
Roland
R
Chassard
Didier
D
Kovar
Andreas
A
D000328:Adult; D018592:Cross-Over Studies; D004347:Drug Interactions; D006801:Humans; D007980:Levodopa / Q000493:pharmacokinetics*; D008297:Male; D009930:Organic Chemicals / Q000494:pharmacology
D009930:Organic Chemicals; D007980:Levodopa; C443959:sarizotan