Russ H, Müller T, Woitalla D, Rahbar A, Hahn J, Kuhn W
Department of Neurology, University of Regensburg, Germany.
Naunyn Schmiedebergs Arch Pharmacol. 1999 Dec;360(6):719-20. doi: 10.1007/s002109900168.
The cerebral availability of the peripherally and centrally acting catechol-O-methyltransferase (COMT) inhibitor tolcapone is not known in humans. Therefore, we determined the concentration of tolcapone in cerebrospinal fluid (CSF) of 12 parkinsonian subjects 1-4 h after oral application of 200 mg of the drug. The mean concentration was 56.4+/-35.5 nmol/l (mean +/- SD). This concentration was calculated to cause 75.2+/-15% (mean +/- SD) inhibition of COMT in CSF. Thus, tolcapone efficiently inhibits COMT after crossing the blood-brain barrier in humans.
