title: Elevated risperidone serum concentrations during acute inflammation, two cases.
abstract: Inflammation-mediated changes in drug metabolism may lead to alterations in the absorption, distribution, and clearance of psychotropic drugs and thus elevate drug levels in blood and lead to intoxications. We report about two patients who developed an up to threefold increase of dose-related serum concentrations of risperidone's active moiety (risperidone plus 9-hydroxyrisperidone) during acute inflammation indicated by elevated C-reactive protein. The two female patients (aged 56 and 38 years, respectively) had the diagnoses of paranoid schizophrenia and schizoaffective disorder. For both patients, there was a close time-dependent parallel fluctuation of drug levels and C-reactive protein. Since elevated drug levels could not be attributed to prescribed comedications, it seemed likely that high-serum concentrations of risperidone were due to inflammation. It is concluded that elevated C-reactive protein should be considered as an indication to control blood levels of risperidone and possibly dose adaption.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center, Mainz, Germany Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center, Mainz, Germany gudrun.hefner@unimedizin-mainz.de.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Hefner
authors.affiliation: Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center, Mainz, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Falter
authors.affiliation: Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center, Mainz, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Bruns
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center, Mainz, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hiemke
mesh_terms: D000208:Acute Disease; D000328:Adult; D014150:Antipsychotic Agents / Q000097:blood* / Q000493:pharmacokinetics; D002097:C-Reactive Protein / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D008875:Middle Aged; D011618:Psychotic Disorders / Q000188:drug therapy*; D018967:Risperidone / Q000097:blood*; D012563:Schizophrenia, Paranoid / Q000188:drug therapy*
chemical_list: D014150:Antipsychotic Agents; D002097:C-Reactive Protein; D018967:Risperidone
keywords: Inflammation; cytochrome P450; intoxication; pharmacokinetics; risperidone