Petr Šilhán

Liquid chromatography-tandem mass spectrometry method for determination of five antidepressants and four atypical antipsychotics and their main metabolites in human serum.

The rapid and simple ultra performance liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous determination parent drugs: sertraline, fluoxetine, citalopram, paroxetine, venlafaxine, clozapine, olanzapine, quetiapine, risperidone, and their active and nonactive metabolites N-desmethylsertraline, norfluoxetine, desmethylcitalopram, didemethylcitalopram, N-desmethylvenlafaxine, O-desmethylvenlafaxine, N-desmethylclozapine, N-desmethylolanzapine, 2-hydroxyolanzapine and 9-hydroxyrisperidone in human serum. Precipitation of serum proteins was performed with a precipitation reagent consisting of 0.05% solution of ZnSO(4)·7H(2)O in acetonitrile/methanol (40:60, v/v). Alprenolol was used as an internal standard. Chromatographic separation was carried out on a BEH C18 column using gradient elution mobile phase A (2 mmol/L ammonium acetate, 0.1% formic acid in 5% acetonitrile, v/v/v) and B (2 mmol/L ammonium acetate, 0.1% formic acid in 95% acetonitrile, v/v/v). Electrospray in positive mode was used for ionization. Detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring. Analysis time was 5 min. Drugs were separated into three groups with low, medium and high levels. Correlation coefficients of calibration curves were in the range 0.995-1.000. Coefficients of variation were 4.2-9.5% for intra-assay and 3.0-11.9% for inter-assay. Recoveries were 87.1-110% for intra-assay and 88.1-108.2% for inter-assay. The method was fully validated and can be successfully applied for routine analyses.

Genome‑Wide Association Studies in Schizophrenia, and Potential Etiological and Functional Implications of Their Results

BACKGROUND Despite the fact that the genetic basis of schizophrenia has been intensively studied for more than two decades, our contemporary knowledge in this field is rather fractional, and a substantial part of it is still missing. The aim of this review article is to sum up the data coming from genome-wide association genetic studies in schizophrenia, and indicate prospective directions of further scientific endeavour. METHODS We searched the National Human Genome Research Institutes Catalog of genome-wide association studies for schizophrenia to identify all papers related to this topic. In consequence, we looked up the possible relevancy of these findings for etiology and pathogenesis of schizophrenia using the computer gene and PubMed databases. RESULTS Eighteen genome-wide association studies in schizophrenia have been published till now, referring to fifty-seven genes supposedly involved into schizophrenias etiopathogenesis. Most of these genes are related to neurodevelopment, neuroendocrinology, and immunology. CONCLUSIONS It is reasonable to predict that complex studies of sufficiently large samples, involving detection of copy number variants and assessment of endophenotypes, will produce definitive discoveries of genetic risk factors for schizophrenia in the future.

Fast simultaneous LC/MS/MS determination of 10 active compounds in human serum for therapeutic drug monitoring in psychiatric medication

A UPLC/MS/MS method with simple protein precipitation has been validated for the fast simultaneous analysis of agomelatine, asenapine, amisulpride, iloperidone, zotepine, melperone, ziprasidone, vilazodone, aripiprazole and its metabolite dehydro-aripiprazole in human serum. Alprenolol was applied as an internal standard. A BEH C18 (2.1 × 50 mm, 1.7 µm) column provided chromatographic separation of analytes using a binary mobile phase gradient (A, 2 mmol/L ammonium acetate, 0.1% formic acid in 5% acetonitrile, v/v/v; B, 2 mmol/L ammonium acetate, 0.1% formic acid in 95% acetonitrile, v/v/v). Mass spectrometric detection was performed in the positive electrospray ionization mode and ion suppression owing to matrix effects was evaluated. The validation criteria were determined: linearity, precision, accuracy, recovery, limit of detection, limit of quantification, reproducibility and matrix effect. The concentration range was as follows: 0.25-1000 ng/mL for agomelatine; 0.25-100 ng/mL for asenapine and iloperidone; 2.5-1000 ng/mL for amisulpride, aripiprazole, vilazodone and zotepine; 2.3-924.6 ng/mL for dehydroaripiprazole; 2.2-878.4 ng/mL for melperone; and 2.2-883.5 ng/mL for ziprasidone. Limits of quantitation below a therapeutic reference range were achieved for all analytes. Intra-run precision of 0.4-5.5 %, inter-run precision of 0.6-8.2% and overall recovery of 87.9-114.1% were obtained. The validated method was successfully implemented into routine practice for therapeutic drug monitoring in our hospital.

A Comparative Study of Tower of London Scoring Systems and Normative Data

Objective Tower of London (ToL) is a planning ability task that includes multiple versions. The original ToL was developed by Shallice together with two scoring systems (ToL-SS). Another two ToL-SS were proposed by Anderson et al. and Krikorian et al. The purpose of this study is to provide normative data for four ToL-SS and explore the effects of demographic variables on ToL performance. Furthermore, we aimed to determine the discriminative validity of these ToL-SS in clinical samples. Method Four groups were included in the study: a normative sample of healthy adults (HC; n = 298); patients with Parkinsons disease with mild cognitive impairment (PD-MCI; n = 52) and without cognitive impairment (PD-ND; n = 57); and patients with schizophrenia (SCH; n = 28). The effects of demographic variables on ToL-SS were examined in the HC group. Between-groups comparisons of ToL-SS were conducted using regression analysis with dummy codes. Results All four ToL-SS were not significantly affected by age, whereas the effect of gender and education is not consistent. ToL-SS significantly (p < .05) differentiate HC from PD-MCI and SCH. Cohens effect size coefficients d range from 0.68 to 1.29. Internal consistency coefficients (Cronbachs α) of ToL-SS range from 0.33 to 0.60. Conclusions Despite poor to questionable internal consistency of ToL-SS, the discriminative validity and clinical utility for assessing planning deficits in PD-MCI and SCH are high. This study provides normative standards for all four ToL-SS on an adult population for use in clinical practice.

Novel treatment options in depression and psychosis

In spite of tremendous development in central nervous system research, current treatment is suboptimal, especially in severe mental disorders. In medicine, there are two main methods of improving the health care provided: seeking new treatment procedures and perfecting (optimizing) the existing ones. Optimization of treatment includes not only practical tools such as therapeutic drug monitoring but also implementation of general trends in the clinical practice. New pharmacological options include new more sophisticated forms of monoaminergic drugs, old drugs rediscovered on the base of a better understanding of pathophysiology of mental illnesses, and drugs aimed at new treatment targets. In depression, treatment resistance to antidepressive pharmacotherapy represents one of the most important clinical challenges. Switching to monotherapy with new multimodal/multifunctional antidepressants and augmentation with new atypical antipsychotics (aripiprazole and brexpiprazole) may be promising options. Further, current evidence supports utility and safety of adjunctive treatment of nutraceuticals. Novel approaches being studied include ketamine and opioids. Recent advances in technology and emerging knowledge about dysfunctional brain circuits and neuroplasticity have led to the development of different new neuromodulation techniques usually used as add-on therapy. Antipsychotics are still the cornerstone of the current treatment of schizophrenia. Two new partial dopamine agonists, brexpiprazole and cariprazine, are now available in addition to aripiprazole. Although the mechanisms of action are similar, the two agents differ in terms of their pharmacodynamic profiles. Further, two new formulations of long-acting injections of second-generation antipsychotics (aripiprazole lauroxil and 3-month paliperidone palmitate) were introduced into clinical practice. New treatment options not yet available include cannabidiol, glutamate modulators, and nicotine receptors agonists.

A Case Report of Clonazepam Dependence: Utilization of Therapeutic Drug Monitoring During Withdrawal Period

AbstractClonazepam is long-acting benzodiazepine agonist used in short-acting benzodiazepine withdrawal; however, recent observations suggest the existence of its abuse.We demonstrate a 40-year-old man with a 20-year history of psychiatric care with recently benzodiazepine dependence (daily intake of ∼60 mg of clonazepam and 10 mg of alprazolam). High serum levels of both drugs were analyzed 3 weeks before admission to hospitalization (clonazepam 543.9 ng/mL, alprazolam 110 ng/mL) and at the time of admission (clonazepam 286.2 ng/mL, alprazolam 140 ng/mL) without any signs of benzodiazepine intoxication. Gradual withdrawal of clonazepam with monitoring of its serum levels and increase of gabapentin dose were used to minimize physical signs and symptoms of clonazepam withdrawal. Alprazolam was discontinued promptly. Clinical consequences of the treatment were controllable tension, intermittent headache, and rarely insomia.It is the first case report showing utilization of therapeutic drug monitoring during withdrawal period in the patient with extreme toleration to severe benzodiazepine dependence.

What Does Antidepressant Drug level Monitoring Reveal About Outpatient Treatment and Patient Adherence

INTRODUCTION The evaluation of plasma levels of antidepressants may improve the treatment outcome. The aim was to verify adherence and adequacy of administered doses of antidepressants among patients hospitalized for inadequate outpatient therapeutic response. METHODS Selective serotonin reuptake inhibitors or venlafaxine plasma levels were assessed on the first day of hospitalization and after 3 days of controlled administration. The patients were considered adherent if the plasma level on admission was within the interval of the minimum and maximum plasma level on the fourth day, expanded by 30%. The adequacy of antidepressant doses used during the outpatient treatment was assessed by comparing the plasma level on the fourth day with the therapeutic reference range. RESULTS Out of 83 patients, 52 (62.7%) were adherent. The plasma levels of antidepressants on the fourth day were found to be within the therapeutic reference range in 35 (43.2%) patients. The same number manifested levels below the therapeutic reference range. In 11 (13.6%) patients, the levels were higher than recommended. No significant difference in rate of adherence was found among individual antidepressants. CONCLUSION The results show that antidepressant nonresponders are frequently under-dosed or nonadherent.

Relationship between rapheal echogenicity and personality as possible markers of a disposition to develop depressive and anxiety disorders

Early diagnosis of anxiety and depression may be facilitated by the use of neurobiological markers. In depression and panic disorder, transcranial sonography (TCS) has revealed decreased echogenicity of the brainstem raphe (BR). The aim of the present study was to detect whether decreased echogenicity of the BR correlates with personality features described in the five-dimension model, especially neuroticism. We examined 100 healthy volunteers using quantitative and qualitative TCS, the five-dimension revised NEO Personality Inventory, Beck´s scales of anxiety and depression, and the Social Re-adjustment Rating Scale (SRRS). Visual BR anechogenicity was found in 11 subjects, BR hypoechogenicity in 29 subjects, and normal BR echogenicity in 60 subjects. The visual assessment correlated with the digital assessment. Comparing the groups with visual BR anechogenicity and BR normoechogenicity, only increased SRRS score and increased agreeableness z-score were significant. Our hypothesis that BR hypoechogenicity reflects an inclination for depression and anxiety characterized by the personality dimension neuroticism was not supported. However, this disposition may be present in a different state, such as stress.