Influence of the Dopamine Agonist α-Dihydroergocryptine on the Pharmacokinetics of Levodopa in Patients with Parkinson's DiseaseMinea, Dan*; Varga, Ioana*; Falup-Pěcurariu, Christian*; de Mey, Christian†; Retzow, Angelika; Althaus, Michael§Clinical Neuropharmacology: July-August 2001 - Volume 24 - Issue 4 - p 235-238 Brief Reports Buy Abstract Author InformationAuthors This study investigated whether chronic coadministration of α-dihydroergocryptine (DHEC) altered the plasma pharmacokinetics of individualized treatments with levodopa in 12 patients with Parkinson's disease. Steady-state pharmacokinetics of plasma levodopa (L-Dopa) under combined treatment were compared with those under treatment with L-Dopa alone. There was no evidence of increased exposure to L-Dopa caused by concomitant treatment with DHEC. In contrast, additional treatment with DHEC reduced the overall exposure to L-Dopa (17.5% reduction in area under the curve; 95% CI: 23%–6%). This effect was small but statistically significant for the area under the plasma concentration–time curve, whereas t max (time of maximum plasma concentration) and peak-to-trough fluctuation were not affected. C max (maximum plasma concentration), on average, was reduced to a similar extent (−14.5%; 95% CI: 38% to −17%), albeit not significantly. The magnitude of the interaction does not suggest changing the current clinical practice of up-titrating DHEC and subsequently adapting L-Dopa to the individual needs of patients. *Department of Neurology, University of Transsilvania, Braşov, Romania; †Applied Clinical Pharmacology Services, Meinz-kastel; and §Desitin Arzneimittel GmbH, Hamburg, Germany Address correspondence and reprint requests to Michael Althaus, Desitin Arzneimittel GmbH Weg beim Jäger 214, 22335 Hamburg, Germany. © 2001 Lippincott Williams & Wilkins, Inc.