Pharmacopsychiatry 2003; 36 - 75
DOI: 10.1055/s-2003-825326

Therapeutic drug monitoring (TDM) of donepezil

A Fellgiebel 1, J Sachse 1, LG Schmidt 1, C Hiemke 1
  • 1Department of Psychiatry, University of Mainz

Donepezil improves cognitive and behaviourial symptoms of patients with mild or moderate dementia of Alzheimer’s type. We have established a new chromatographic method for determination of donepezil and analysed 12 serum samples of patients treated with donepezil. The method exhibited linearity for concentrations up to at least 90 ng/ml. Coefficients of variance were below 5%, and the limit of quantification was 5 ng/ml. Patients under 5mg donepezil daily (n=5; mean age: 71.8 years) showed mean serum levels of 25±8 ng/ ml (range: 17–38 ng/ ml). Under 10mg donepezil (n=7; mean age: 73.1 years) the mean donepezil concentration was 38±16 ng/ ml (range: 21–69 ng/ ml). In the natural setting of our pilot study only one patient reached donepezil concentrations between 50 and 70 ng/ml which are recommended for optimal response. It is concluded that TDM could be useful for optimisation of drug therapy.