TY  - JOUR
A1  - Taurines, R.
A1  - Fekete, S.
A1  - Preuss-Wiedenhoff, A.
A1  - Warnke, A.
A1  - Wewetzer, C.
A1  - Plener, P.
A1  - Burger, R.
A1  - Gerlach, M.
A1  - Romanos, M.
A1  - Egberts, K. M.
T1  - Therapeutic drug monitoring in children and adolescents with schizophrenia and other psychotic disorders using risperidone
JF  - Journal of Neural Transmission
N2  - Risperidone is commonly used to treat different psychiatric disorders worldwide. Knowledge on dose–concentration relationships of risperidone treatment in children and adolescents with schizophrenia or other psychotic disorders is, however, scarce and no age-specific therapeutic ranges have been established yet. Multicenter data of a therapeutic drug monitoring service were analyzed to evaluate the relationship between risperidone dose and serum concentration of the active moiety (risperidone (RIS) plus its main metabolite 9-hydroxyrisperidone (9-OH-RIS)) in children and adolescents with psychotic disorders. Patient characteristics, doses, serum concentrations and therapeutic outcomes were assessed by standardized measures. The study also aimed to evaluate whether the therapeutic reference range for adults (20–60 ng/ml) is applicable for minors. In the 64 patients (aged 11–18 years) included, a positive correlation between daily dose and the active moiety (RIS\(_{am}\)) concentration was found (r\(_s\) = 0.49, p = 0.001) with variation in dose explaining 24% (r\(_s\)\(^2\) = 0.240) of the variability in serum concentrations. While the RIS\(_{am}\) concentration showed no difference, RIS as well 9-OH-RIS concentrations and the parent to metabolite ratio varied significantly in patients with co-medication of a CYP2D6 inhibitor. Patients with extrapyramidal symptoms (EPS) had on average higher RIS\(_{am}\) concentrations than patients without (p = 0.05). Considering EPS, the upper threshold of the therapeutic range of RIS\(_{am}\) was determined to be 33 ng/ml. A rough estimation method also indicated a possibly decreased lower limit of the preliminary therapeutic range in minors compared to adults. These preliminary data may contribute to the definition of a therapeutic window in children and adolescents with schizophrenic disorders treated with risperidone. TDM is recommended in this vulnerable population to prevent concentration-related adverse drug reactions.
KW  - risperidone
KW  - children
KW  - serum concentration
KW  - schizophrenia
KW  - therapeutic drug monitoring
KW  - pharmacovigilance
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324833
VL  - 129
IS  - 5-6
ER  - 
TY  - JOUR
A1  - Fekete, Stefanie
A1  - Egberts, K.
A1  - Preissler, T.
A1  - Wewetzer, C.
A1  - Mehler-Wex, C.
A1  - Romanos, M.
A1  - Gerlach, M.
T1  - Estimation of a preliminary therapeutic reference range for children and adolescents with tic disorders treated with tiapride
JF  - European Journal of Clinical Pharmacology
N2  - Purpose
Tiapride is commonly used in Europe for the treatment of tics. The aim of this study was to examine the relationship between dose and serum concentrations of tiapride and potential influential pharmacokinetic factors in children and adolescents. In addition, a preliminary therapeutic reference range for children and adolescents with tics treated with tiapride was calculated.

Methods
Children and adolescents treated with tiapride at three university hospitals and two departments of child and adolescents psychiatry in Germany and Austria were included in the study. Patient characteristics, doses, serum concentrations, and therapeutic outcome were assessed during clinical routine care using standardised measures.

Results
In the 49 paediatric patients (83.7% male, mean age = 12.5 years), a positive correlation was found between tiapride dose (median 6.9 mg/kg, range 0.97–19.35) and serum concentration with marked inter-individual variability. The variation in dose explained 57% of the inter-patient variability in tiapride serum concentrations; age, gender, and concomitant medication did not contribute to the variability. The symptoms improved in 83.3% of the patients. 27.1% of the patients had mild or moderate ADRs. No patient suffered from severe ADRs.

Conclusions
This study shows that tiapride treatment was effective and safe in most patients with tics. Compared with the therapeutic concentration range established for adults with Chorea Huntington, our data hinted at a lower lower limit (560 ng/ml) and similar upper limit (2000 ng/ml).
KW  - Tourette syndrome
KW  - therapeutic drug monitoring
KW  - serum concentration
KW  - paediatrics
KW  - pharmacokinetics
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-279893
VL  - 77
IS  - 2
ER  -