Simpson K H, Murphy P, Colthup P V, Whelan P
University Department of Anaesthesia, St. James's University Hospital, Leeds, UK.
Psychopharmacology (Berl). 1992;109(4):497-8. doi: 10.1007/BF02247730.
This study measured the concentrations of ondansetron in plasma and cerebrospinal fluid (CSF) in six volunteers after oral dosing to steady state. Ondansetron concentrations ranged from 39.5-147 ng ml-1 in plasma and from 2.6-15.4 ng ml-1 in CSF. There was good correlation between plasma and CSF concentrations (r = 0.89, p = 0.017). CSF concentrations were less than 15% of plasma concentrations in all cases, indicating that the rate of penetration of the blood brain barrier by ondansetron is low.
