The single- and repeated-dose pharmacokinetics of sabeluzole have been determined in six elderly patients with [senile] dementia of the Alzheimer type. After a single oral dose of 10 mg sabeluzole, the peak plasma concentration was attained at 1 to 4 h; it averaged 42 ng.ml-1. On repeated dosing (10 mg b.d.), steady-state was virtually attained after 3 days of treatment. Steady-state mean trough and peak plasma concentrations fluctuated between 53 and 94 ng.ml-1. The mean terminal half-life after a single dose and at steady-state was of the order of 33 h. Sabeluzole was well tolerated and at the end of treatment, no systematic changes in blood haematology, biochemistry or urinalysis were seen.