Therapeutic drug monitoring of children and adolescents treated with aripiprazole: observational results from routine patient care.

Although aripiprazole is one of the most used antipsychotics, knowledge about serum concentrations in children and adolescents is scarce and age-specific therapeutic ranges have not been established yet. Data of a routine therapeutic drug monitoring service were analyzed in order to evaluate the relationship between dose and serum concentration of aripiprazole in children and adolescents. The study also aimed to evaluate whether the therapeutic reference range defined for adults with schizophrenia (100-350 ng/ml) is applicable for minors. Data from 130 patients (aged 7-19 years) treated with aripiprazole for different indications in doses of 2-30 mg/day were evaluated. Patient characteristics, doses, serum concentrations and therapeutic outcome were assessed by standardized measures. A positive mean correlation between body weight-corrected daily dose and aripiprazole concentration was found (rp = 0.59, p < 0.001) with variation in dose explaining 35% of the variability in serum concentrations. Girls had on average 41% higher dose-corrected concentrations than boys (244.9 versus 173.4 mg/l; p = 0.006). Aripiprazole concentrations did not vary with co-medication (p = 0.22). About 70% of all measured serum concentrations were within the recommended therapeutic range for adults. Using a calculation method in all responding patients with an ICD-10 F2 diagnosis for a rough estimation of a preliminary therapeutic window also demonstrated a similar therapeutic range of aripiprazole in minors (105.9-375.3 ng/ml) than for adults. If confirmed in larger samples and more controlled study designs, these data may contribute to the definition of a therapeutic range of aripiprazole concentrations in children and adolescents.

[Polypharmacy of psychotropic drugs in child and adolescent psychiatry in Germany - rather the rule than the exception]. / Polypharmazie in der Anwendung von Psychopharmaka in der deutschen Kinder- und Jugendpsychiatrie ­ häufiger Regel als Ausnahme.

Polypharmacy of psychotropic drugs in child and adolescent psychiatry in Germany - rather the rule than the exception Abstract. Background: Polypharmacy increases the risk of interactions and enhances the chance of adverse drug reactions (ADRs). Hence, child and adolescent psychiatrists generally try to avoid polypharmacy with psychotropic drugs. However, only little data regarding the frequency of polypharmacy in child and adolescent psychiatry are available. This study analyzes clinical data on polypharmacy and the possible association with a higher risk of ADRs in Germany, with a focus on antidepressants and antipsychotics. Methods: We investigated a total of 940 datasets from descriptive studies on therapeutic drug monitoring (TDM) of pediatric patients treated with different psychotropic drugs. Results: The frequency of polypharmacy ranged up to 45.6 % (escitalopram) and 72.1 % (olanzapine). In 17.4 % of the cases, polypharmacy consisted of four or more psycho-/neuropharmacological substances. No increased incidence of ADRs was reported with polypharmacy of antipsychotics compared to monotherapy. Polypharmacy with sertraline was associated with a higher number of ADRs. Discussion and Conclusion: There is a high prevalence of polypharmacy with psychotropic drugs in child and adolescent psychiatry in Germany. Conclusions concerning individual drugs should be drawn with care since the subsample sizes were relatively small. However, our results do provide an indication of the prevalence of polypharmacy, although the validity of the data is limited. There is an urgent need to analyze data from larger and more homogeneous groups under more controlled conditions.

Relationship Between Daily Dose, Serum Concentration, and Clinical Response to Quetiapine in Children and Adolescents with Psychotic and Mood Disorders.

Introduction In child and adolescent psychiatry, therapeutic drug monitoring (TDM) is strongly recommended. However, therapeutic ranges (TR) are defined only for adults. The objectives of this naturalistic study were to assess the relationships between serum quetiapine concentration, daily dose, and clinical outcomes as well as the determinants of pharmacokinetic variability. Furthermore, it was elucidated whether the recommended TR for adult patients with psychotic disorders is valid for children and adolescents. Methods TDM was performed in 180 pediatric patients treated with quetiapine. Psychopathological changes were assessed by the Clinical Global Impression - Improvement scale (CGI-I). Adverse drug reactions (ADRs) were assessed by using a short form of the Udvalg for Kliniske Undersogelser (UKU) side effect rating scale. Results A weak positive linear relationship between daily dose (mean 349.9±248.9 mg/day) and serum concentration of quetiapine (rs=0.496, p<0.001) was found (mean age 15.6±1.9 years, 45.6% male, 31.1% monotherapy), but no relationship between serum concentration and clinical outcome was found. Dose variation accounted for only 12.5% (rs2=0.125) of the variability of serum concentrations. No effects by gender, age, body weight, smoking habits, and co-medication were found. The majority of patients with psychotic (67.8%) and mood disorders (74.5%) showed a serum concentration below the suggested lower limit (100 ng/mL) of the TR for adults. Discussion There are several limitations of this study because of the naturalistic design, and our results should therefore be interpreted with caution. Notwithstanding, our data suggest that the lower limit of the TR for quetiapine is lower than the limit in adult patients.

Therapeutic Drug Monitoring in Children and Adolescents Under Pharmacotherapy With Olanzapine in Daily Clinical Practice.

BACKGROUND: The relationship between daily dose, serum concentrations, and clinical outcomes of olanzapine as well as the influencing factors thereof in children and adolescents treated for different psychiatric disorders were investigated in daily clinical practice. In addition, it was examined whether the current recommended therapeutic range (TR) for adult patients with psychotic disorders is valid for minors. METHODS: The Competence Network for Therapeutic Drug Monitoring (www.tdm-kjp.com) routinely collects demographic and clinical outcome data as well as serum concentrations of children and adolescents treated with psychotropics. The therapeutic effect is documented using the Clinical Global Impression Scale subscale for Global Improvement. Adverse drug reactions (ADRs) are assessed using the Udvalg for Kliniske Undersogelser-Side Effect Rating Scale. RESULTS: One hundred fifteen patients (mean age = 15.9 years; range = 10.4-18.8 years; 40.9% male) were included. The majority (72.1%) was cotreated with other psychotropic drugs. A positive medium linear relationship (r = 0.619; P < 0.001) between olanzapine dose (mean = 11.64 mg/d) and serum concentration (mean = 35.65 ng/mL) was found with a marked interindividual variability of serum concentrations. Neither relationship between olanzapine serum concentration and treatment response (clinical benefit documented in 80%) nor ADRs (documented in 53.3%, in 7.5% judged as severe) was detected. Most of the patients with psychotic and eating disorders (68.8% and 71.8%, respectively) had an olanzapine serum concentration within the TR suggested for adults. CONCLUSIONS: There are several limitations of this study because of the naturalistic design, and our results should therefore be interpreted with caution. As most of the patients showed a clinical benefit under olanzapine concentrations within the TR for adults and only a minority had severe ADRs, it is reasonable to conclude a similar TR for children, adolescents, and adults.

Therapeutic drug monitoring as a measure of proactive pharmacovigilance in child and adolescent psychiatry.

INTRODUCTION: Off-label or unlicensed use of psychotropic drugs is common rather than the exception in child and adolescent psychiatry. This use exposes patients to an unknown additional risk of ineffective or even harmful treatment. In addition, treatment with psychotropic drugs during a period of life when the patient undergoes marked developmental hormonal and neurobiological changes often requires different dosing regimes in later life and may result in adverse drug reactions, which are either not seen in adults at all or not in the same frequency. Areas covered: Given these critical safety issues, efficient pharmacovigilance methods as part of routine practice are essential for the improvement of patient care. The purpose of this article is to introduce methods to increase the safety of psychotropic drug use in youngsters. In particular, therapeutic drug monitoring (TDM) as a routine measure of proactive pharmacovigilance is discussed. Expert opinion: Given the special features of psychopharmacological therapy in children and adolescents in day-to-day clinical practise, proactive surveillance by using a close standardized 'patient monitoring' and long-term follow-up with TDM is very important. This approach could minimize the risk of exposing paediatric patients to ineffective treatments of uncertain or unknown risks.

Relationship between clozapine dose, serum concentration, and clinical outcome in children and adolescents in clinical practice.

Information on dose- and concentration-related clinical effects of clozapine treatment in children and adolescents is scarce. This study aimed to examine the relationship between dose, serum concentration, and clinical outcome as well as the influencing factors thereof in paediatric patients treated with clozapine. Data from a routine Therapeutic Drug Monitoring (TDM) service between 2004 and 2014 were studied in 68 patients, aged 11-18 years. Severity of illness, therapeutic effectiveness and adverse drug reactions (ADRs) were assessed by standardized means. A relationship between the daily dose (mean 319 mg, 4.9 mg/kg) and serum concentration (mean 387 ng/ml) of clozapine was found with the variation in dose explaining 30 % of the variability in clozapine serum concentrations. Also gender contributed to the variability, however, no influence of age or concomitant medications was detected. Furthermore, a significant association was found between clozapine serum concentration and the occurrence of ADRs. Patients without ADRs had a lower mean serum concentration than those with mild (261.4 vs 407.3 ng/ml, P = 0.018) and moderate ADRs (261.4 vs 416.3 ng/ml, P = 0.028). As clozapine was estimated to be effective in lower blood concentrations, guidance on a possibly lower therapeutic range of clozapine serum levels in paediatric patients is provided. With ADRs increasing under higher concentrations, TDM is strongly recommended in paediatric clozapine therapy for individualized dosing. Dose adjustment in females also might be reasonable according to gender-related differences in serum concentrations. However, regarding the limitations of this study results should be validated in larger studies with more standardized designs.

[Pharmacovigilance in child and adolescent psychiatry]. / Pharmakovigilanz in der kinder- und jugendpsychiatrie.

Rational pharmacotherapy is a challenging task in child and adolescent psychiatry. Increasing prescription numbers contrast with the uncertainties of safety and efficacy issues. The lack of clinical (authorization) trials often implies a non- age-specific use of drugs. However, young patients show particular metabolic conditions and a higher vulnerability for adverse drug reactions. Thus it seems mandatory to create age-specific pharmacological data about efficacy and safety of psychotropic drug use in minors. Legislation authorities became aware of this situation and introduced European and national scientific pharmacovigilance regulations and programmes accordingly in order to continuously evaluate the benefit-risk-ratio, detect, collect, minimize, and prevent adverse effects of drugs by appropriate measures, e.g., therapeutic drug monitoring. In this paper the principles and needs of pharmacovigilance in child and adolescent psychiatry are discussed. Furthermore a large multicenter clinical trial («TDM-VIGIL¼), funded by the German Federal Institute for Drugs and Medical Devices, is presented, which appeals to collect epidemiological prescription and safety data of psychotropic drugs in children and adolescents using an internet-based data infrastructure (patient registry).

The relation between dosage, serum concentrations, and clinical outcome in children and adolescents treated with sertraline: a naturalistic study.

OBJECTIVE: This naturalistic therapeutic drug monitoring (TDM) study aimed to evaluate the relationship between dosage, serum concentration, and clinical outcome in children and adolescents treated with the serotonin reuptake inhibitor sertraline for different indications. METHODS: Steady-state trough serum concentrations were analyzed in 90 subjects, treated with 25-200 mg sertraline per day. Therapeutic efficacy was assessed by the Clinical Global Impression Improvement subscale and side effects by the Udvalg for Kliniske Undersogelser-Side Effect Rating Scale. RESULTS: In the study population, children were administered higher body weight normalized daily doses than adolescents. The relationships between sertraline daily dosage and serum concentrations (rs = 0.67, P < 0.0001) as well as between body weight normalized daily doses and serum concentrations (r = 0.62, P < 0.0001) were linear. In the whole patient group, no correlation between serum concentrations and either the therapeutic effect or side effects could be observed, neither significant effects of gender, age, concomitant medications, or smoking habits. When analyzing just the patients with depression, those with side effects had significantly higher sertraline serum concentrations than those without (44.8 ng/mL versus 22.3 ng/mL, P = 0.01). In general, occurrence of side effects was significantly more frequent in patients with psychiatric comedication (37.9%) than those without (11.5%, P = 0.002). DISCUSSION: As this study has the typical limitations of naturalistic studies, the results should be interpreted cautiously. From the data, it is not possible to suggest an age-specific therapeutic window for children and adolescents. However, as the intraindividual variability of sertraline serum concentrations is known to be low, TDM may certainly help to predict serum concentrations after dose adjustment, to assess pharmacokinetic drug-drug interactions influencing serum concentrations and the patient's compliance, finally allowing for personalizing dose through TDM.

Bone mineral density in partially recovered early onset anorexic patients - a follow-up investigation.

BACKGROUND AND AIMS: There still is a lack of prospective studies on bone mineral development in patients with a history of early onset Anorexia nervosa (AN). Therefore we assessed associations between bone mass accrual and clinical outcomes in a former clinical sample. In addition to an expected influence of regular physical activity and hormone replacement therapy, we explored correlations with nutritionally dependent hormones. METHODS: 3-9 years (mean 5.2 +/- 1.7) after hospital discharge, we re-investigated 52 female subjects with a history of early onset AN. By means of a standardized approach, we evaluated the general outcome of AN. Moreover, bone mineral content (BMC) and bone mineral density (BMD) as well as lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). In a substudy, we measured the serum concentrations of leptin and insulin-like growth factor-I (IGF-I). RESULTS: The general outcome of anorexia nervosa was good in 50% of the subjects (BMI >/= 17.5 kg/m2, resumption of menses). Clinical improvement was correlated with BMC and BMD accrual (chi2 = 5.62/chi2 = 6.65, p = 0.06 / p = 0.036). The duration of amenorrhea had a negative correlation with BMD (r = -.362; p < 0.01), but not with BMC. Regular physical activity tended to show a positive effect on bone recovery, but the effect of hormone replacement therapy was not significant. Using age-related standards, the post-discharge sample for the substudy presented IGF-I levels below the 5th percentile. IGF-I serum concentrations corresponded to the general outcome of AN. By contrast, leptin serum concentrations showed great variability. They correlated with BMC and current body composition parameters. CONCLUSIONS: Our results from the main study indicate a certain adaptability of bone mineral accrual which is dependent on a speedy and ongoing recovery. While leptin levels in the substudy tended to respond immediately to current nutritional status, IGF-I serum concentrations corresponded to the individual's age and general outcome of AN.

Structural abnormality of the substantia nigra in children with attention-deficit hyperactivity disorder.

BACKGROUND: Structural abnormality of the substantia nigra can be detected by transcranial sonography in neuropsychiatric disorders such as Parkinson disease and restless legs syndrome. We investigated echogenicity of the substantia nigra as a potential structural marker for dysfunction of the nigrostriatal dopamine system in children with attention-deficit hyperactivity disorder (ADHD). METHODS: We used a blinded design and determined echogenicity of the substantia nigra by use of transcranial sonography in 22 children with ADHD and 22 healthy controls matched for age and sex. RESULTS: The echogenic substantia nigra area was significantly larger in ADHD patients than in healthy controls (F(1,42) = 9.298, p = 0.004, effect size = 0.92). We found no effects of age or sex. LIMITATIONS: Owing to a lack of dimensional assessment, we could not analyze the correlation between echogenicity and clinical symptoms. CONCLUSION: Our results support the hypothesis that the nigrostriatal dopaminergic system is abnormal in children with ADHD.

Serum protein profiling and proteomics in autistic spectrum disorder using magnetic bead-assisted mass spectrometry.

The pathophysiology of autistic spectrum disorder (ASD) is not fully understood and there are no diagnostic or predictive biomarkers. Proteomic profiling has been used in the past for biomarker research in several non-psychiatric and psychiatric disorders and could provide new insights, potentially presenting a useful tool for generating such biomarkers in autism. Serum protein pre-fractionation with C8-magnetic beads and protein profiling by matrix-assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDI-ToF-MS) were used to identify possible differences in protein profiles in patients and controls. Serum was obtained from 16 patients (aged 8-18) and age-matched controls. Three peaks in the MALDI-ToF-MS significantly differentiated the ASD sample from the control group. Sub-grouping the ASD patients into children with and without comorbid Attention Deficit and Hyperactivity Disorder, ADHD (ASD/ADHD+ patients, n = 9; ASD/ADHD- patients, n = 7), one peak distinguished the ASD/ADHD+ patients from controls and ASD/ADHD- patients. Our results suggest that altered protein levels in peripheral blood of patients with ASD might represent useful biomarkers for this devastating psychiatric disorder.

Expression analyses of the mitochondrial complex I 75-kDa subunit in early onset schizophrenia and autism spectrum disorder: increased levels as a potential biomarker for early onset schizophrenia.

Searching for a peripheral biological marker for schizophrenia, we previously reported on elevated mitochondrial complex I 75-kDa subunit mRNA-blood concentrations in early onset schizophrenia (EOS). The aim of this study was to further evaluate the utility of this gene as a potential marker for schizophrenia. Both-schizophrenia and autism-are suggested to be neuronal maldevelopmental disorders with reports of mitochondrial dysfunction and increased oxidative stress. Therefore we have investigated the expression levels of mitochondrial complex I 75-kDa subunit mRNA in whole blood of children with autistic spectrum disorder (ASD) and a group of adolescent acute first-episode EOS patients in comparison to matched controls. We have found that compared to the respective controls only the group of EOS patients-and not the ASD group-showed a significantly altered expression of the complex I 75-kDa subunit mRNA. Although further studies are necessary to test for the specificity of this marker, our findings point to the potential use of the mitochondrial complex I as a biomarker for schizophrenia.

Drug monitoring in child and adolescent psychiatry for improved efficacy and safety of psychopharmacotherapy.

Most psychotropic drugs used in the treatment of children and adolescents are applied "off label" with a direct risk of under- or overdosing and a delayed risk of long-term side effects. The selection of doses in paediatric psychiatric patients requires a consideration of pharmacokinetic parameters and the development of central nervous system, and warrants specific studies in children and adolescents. Because these are lacking for most of the psychotropic drugs applied in the Child and Adolescent and Psychiatry, therapeutic drug monitoring (TDM) is a valid tool to optimise pharmacotherapy and to enable to adjust the dosage of drugs according to the characteristics of the individual patient. Multi-centre TDM studies enable the identification of age- and development-dependent therapeutic ranges of blood concentrations and facilitate a highly qualified standardized documentation in the child and adolescent health care system. In addition, they will provide data for future research on psychopharmacological treatment in children and adolescents, as a baseline for example for clinically relevant interactions with various co-medications. Therefore, a German-Austrian-Swiss "Competence Network on Therapeutic Drug Monitoring in Child and Adolescent Psychiatry" was founded 1 introducing a comprehensive internet data base for the collection of demographic, safety and efficacy data as well as blood concentrations of psychotropic drugs in children and adolescents.

Weight gain in children and adolescents during 45 weeks treatment with clozapine, olanzapine and risperidone.

The aim of this study was to evaluate long-term weight gain associated with clozapine, olanzapine, and risperidone treatment and its clinical risk factors in children and adolescents. At four child and adolescent psychiatric departments, the weight and body mass index of initially hospitalized patients (aged 9.0-21.3 years) treated with clozapine (n = 15), olanzapine (n = 8), and risperidone (n = 10) were prospectively monitored for 45 weeks. Clinical risk factors (age, gender, baseline weight, dosage, drug-naivety) were tested for their association with weight gain in the three groups. All three groups experienced significant weight gain between baseline and endpoint. The absolute and percentage average weight gains were significantly higher for the olanzapine group (16.2 +/- 8.8 kg; 30.1 +/- 18.9%) than for the clozapine (9.5 +/- 10.4 kg; 14.8 +/- 15.8%) and the risperidone (7.2 +/- 5.3 kg; 11.5 +/- 6.0%) groups. Olanzapine is associated with extreme long-term weight gain in children and adolescents that, in addition, is much higher than that expected in adults. Clozapine and risperidone are associated with a less marked weight gain in children and adolescents but also much higher than that expected in adults. These differences may affect compliance with medication and health risk.

[Genetic findings in schizophrenia]. / Genetische Befunde zu Schizophrenie.

Schizophrenia is characterized by a great heterogeneity of symptoms and functional deficits, especially of cognition. Different phenotypes are thought to result from the interaction of genetic predisposition and environmental factors. Pathophysiological models range from the dopamine and glutamate hypotheses to the hypothesis of free radicals and the hypotheses of neurodevelopment as opposed to neurodegeneration. In addition to the neurobiological approaches, linkage studies and subsequent finemappings deliver evidence with regard to genes potentially involved in schizophrenia. The most important candidate genes, such as dysbindin (DTNBP1), neuregulin (NRG1) and DISC-1 (disrupted-in schizophrenia-1), are thought to influence neurotransmission, as well as the development and maintenance of the structure of neuronal networks. The list of potential candidates includes numerous other genes as well. In conclusion, multiple genetic, neurobiological, and exogenous factors are assumed to interact in the pathogenesis of schizophrenia.

Effectiveness and tolerability of olanzapine in the treatment of adolescents with schizophrenia and related psychotic disorders: results from a large, prospective, open-label study.

OBJECTIVE: The aim of this study was to assess effectiveness and tolerability of oral olanzapine treatment of adolescents with schizophrenic disorders. METHOD: Adolescent patients (12-19 years) with schizophrenia, schizoaffective, or schizophreniform disorders according to the Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition (DSM-IV) were enrolled in a multicenter, prospective, open-label study. Following a 2- to 9-day washout period, patients initially received 10 mg/day olanzapine. Dose modification was allowed during week 2 (dose range 5-15 mg/day) and during weeks 3-6 (dose range, 5-20 mg/day). Responders (improvement > or =30% on the Brief Psychiatric Rating Scale, BPRS) continued olanzapine for additional 18 weeks. Psychopathology was assessed using BPRS and Clinical Global Impressions (CGI) scales; side effects were assessed by adverse event reporting. RESULTS: Out of 96 patients enrolled at 10 sites, 60 (62.5%) met response criteria at week 6. Mean BPRS total scores decreased significantly (p < 0.001) from baseline (39.2 +/- 13.4) to week 6 last observation carried forward (LOCF) (22.2 +/- 14.7). The rate of patients considered markedly ill or worse (CGI-S) decreased from 83.3% (baseline) to 37.5% (week 6, LOCF). The most common reported adverse event was weight gain (30.2%, 29/96). Three patients (3.1%) discontinued due to adverse events. CONCLUSIONS: In this study of young patients with schizophrenia, schizoaffective, or schizophreniform disorders, olanzapine treatment was associated with marked symptom improvement. As changes in weight and prolactin levels may be greater in adolescent than in adult patients, potential risks and benefits of olanzapine treatment in adolescents should be considered carefully.