Pharmacopsychiatry 2005; 38 - 31
DOI: 10.1055/s-2005-862644

Risperidone Plasma Levels in the Elderly with Dementia

M Fric 1, G Laux 1, ML Rao 2, R Schmidmeier 1, J Eberl 1, T Kirchmeier 1, F Betzl 1, A Brunnauer 1
  • 1District Hospital Gabersee, Wasserburg a. Inn, Germany
  • 2Department of Psychiatry, University of Bonn, Germany

The benefit of therapeutic drug monitoring (TDM) of neuroleptics is very critical discussed. For conventional antipsychotics like haloperidol, fluphenazine, trifluoperazine and perphenazine optimal blood level ranges were defined, data with regard to novel antipsychotics are not established so far.

Similarly an optimal blood level range of risperidone is not known. There were large variations in inter- and intraindividual values of plasma concentration of risperidone, due to a variety of physiologic, genetic and environmental factors. Blood level ranges from 14–58 resp. 23–46 ng/ml were reported.

The aim of our study was the determination of risperidone plasma levels in elderly patients. The results showed significant higher blood levels (Ø 58,1 ng/ml) in patients over 65 years despite treatment with low doses of risperidone (Ø 1,7mg/d).