Prescribing Patterns and the Use of Therapeutic Drug Monitoring of Psychotropic Medication in a Psychiatric High-Security Unit

Abstract

The aim of this study was to investigate the use of psychotropic medication and therapeutic drug monitoring in a high-security psychiatric unit and to compare the doses and serum concentrations both with the recommended intervals and with the doses and serum concentrations in a control group. One hundred thirty-two patients were admitted in the period from January 2000 to December 2005. All available samples were used when comparing serum concentrations and doses with the recommended ranges. For the comparison of doses and serum concentration-to-dose (C:D) ratios with the control group only 1 sample from each patient was used. A total of 459 analyses of 27 different drugs in samples from 8 women and 73 men were included. The median number of therapeutic drug monitoring analyses per patient was 4 (range 1-29). Thirty-seven of the 81 patients (46%) used 2 or more antipsychotics at the same time. Clozapine, lamotrigine, olanzapine, quetiapine, ziprasidone, and zuclopenthixol were often given in doses above the recommended. The serum levels were frequently above those recommended for clozapine, olanzapine, quetiapine, risperidone, ziprasidone, and zuclopenthixol. The serum levels were significantly higher in the study group than in the control group for clozapine, lamotrigine, quetiapine, and zuclopenthixol. The given dose was significantly higher in the study group than in the control group for clozapine, lamotrigine and zuclopenthixol. The C:D ratio was significantly lower in the study group than in the control group for olanzapine but higher for quetiapine. The non-evidence based practice of high-dose polypharmacy with several antipsychotics is widely used in this unit. The use of higher doses in the study group than in the control group was not due to differences in metabolism or adherence to treatment between the 2 groups. The frequent use of therapeutic drug monitoring did not seem to have a great impact on the prescribed doses.

Prevalence and correlates of antipsychotic polypharmacy: A systematic review and meta-regression of global and regional trends from the 1970s to 2009

“…Consistent with prior reports (Biancosino et al, 2005; Brunot et al, 2002; Castberg and Spigset, 2008; Fourrier et al, 2000; Kreyenbuhl et al, 2007b; Lelliott et al, 2002; Millier et al, 2011; Morrato et al, 2007; Stroup et al, 2009; Tibaldi et al, 1997), APP was associated with variables that indicate patients had higher illness severity and, possibly refractoriness (Barbui et al, 2006b; Tomasi et al, 2006), including schizophrenia diagnosis, inpatient status, greater LAI use and shorter follow-up. Moreover, the fact that cross-sectional studies and those with shorter follow-up tended to have higher APP rates, suggests that at least some of the APP was either part of cross-titration or transient.…”

Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017

“…To achieve these goals, adherence to medication, mostly consisting of antipsychotic drugs, is essential, since most forensic psychiatric patients disapprove of pharmacotherapy [824,825]. Castberg and Spigset [184] analyzed data of a high security forensic unit and found higher prescribed doses in forensic patients than in a control group, whereas the dose-related concentrations were significantly lower for olanzapine but higher for quetiapine in the forensic patients. TDM is highly recommended for this group of patients especially when supervised as outpatients.…”

Prevalence and correlates of antipsychotic polypharmacy in children and adolescents receiving antipsychotic treatment

“…Although a strong association between schizophrenia and APP has been demonstrated in adults (Biancosino et al 2006; Castberg & Spigset 2008; Fourrier et al 2000; Morrato et al 2007) and in two paediatric studies (Constantine et al 2010; dosReis et al 2011), schizophrenia-spectrum disorders were not correlated with APP in the overall reviewed database. This may be a problem of sample size or related to the different indications of use of APP in younger populations.…”