The relevance of prolonged QTc measurement to pediatric psychopharmacology

Potential drug-drug interactions with psychotropic drugs in paediatric inpatients: A cross-sectional study

AIMS

Polypharmacy and drug-drug interactions (DDIs) are important problems that necessitate more attention in paediatric inpatients. This study aimed to determine and evaluate DDIs in paediatric inpatients using psychotropic drugs.

METHODS

It was conducted as a retrospective cross-sectional study. Inpatients consulted by child and adolescent psychiatrists (CAPs) and had at least one psychotropic drug-using between January 2016 and September 2017 were retrospectively included. To determine the clinical significance of DDIs by Micromedex^® and DDI Predictor online databases. DDIs between psychotropic and other drugs, the type, severity, and duration of potential DDIs were evaluated.

RESULTS

During the study period, 564 patients' records were reviewed and 200 patients were considered eligible and included in the study. The median (min-max) age was 13.70 (1.5-17.83) years. The mean (SD) number of psychotropics used during hospitalisation was 1.29 (0.55) and the total number of drugs was 7.39 (4.45). A total of 336 potential DDIs were detected (2.19 DDIs/patient) in all patients. The most common potential outcome of psychotropic DDIs was drug-induced QTc prolongation (67.56%). While 92.85% of the potential DDIs were "contraindicated" or "major," only 18.46% had a "good" or "excellent" strength of evidence. The risk of psychotropic polypharmacy (OR:0.73, 95% CI 0.59-0.92; p:0.006) and DDIs (OR:0.69, 95% CI 0.35-0.76; p:0.033) was significantly higher in patients without primary psychiatric disorders. When the total number of drugs and the total number of potential DDIs were compared amongst all inpatient units, significant differences were found between paediatric hematology-general paediatrics (mean difference: 2.002; P < .001) and paediatric hematology-paediatric ICU (mean difference: 1.650; P = .012), respectively.

CONCLUSION

Psychotropic drug-related DDI is a major problem in the paediatric population and the clinical significance of the potential DDIs' risk should be determined in patient-centred care and managed by the multidisciplinary team.

Evaluation of the use of chlorpromazine for agitation in pediatric patients

Introduction

Chlorpromazine is a first-generation antipsychotic used for behavioral problems in pediatric patients. However, other therapies may demonstrate both improved outcomes and fewer side effects. Within our institution, chlorpromazine has been the standard medication used for treatment of pediatric agitation. The study objective was to evaluate the appropriateness of chlorpromazine use (including efficacy, appropriate dosing, drug interactions, and tolerability) to optimize the treatment of pediatric agitation.

Methods

Data regarding drug interactions, patient behavior, dosing, and side effects was collected for each patient administered chlorpromazine from January 2019 through June 2019. Data were analyzed using descriptive statistics assessing the incidence of drug-drug interactions (DDIs), incidences of inefficacy, inappropriate dosing, and side effects.

Results

A total of 70 patients and 130 administrations of oral or intramuscular chlorpromazine were evaluated. Of these administrations, 49 (38%) resulted in a DDI. Eighteen (14%) administrations were ineffective for managing symptoms of agitation. Eleven (8%) administrations were dosed inappropriately, and 46 (35%) administrations resulted in side effects possibly caused by chlorpromazine.

Discussion

Results from this study demonstrate opportunities for improvement in patient care due to instances of drug interactions, inefficacy, inappropriate dosing, and side effects with the use of chlorpromazine.

Evaluation of QTc Interval Effects of Antipsychotic Medications for Intensive Care Unit Delirium in Pediatric Patients

OBJECTIVE

Intensive care unit delirium is an increasingly recognized problem in pediatric patients. Controversy exists regarding the safety and efficacy of antipsychotic medications for this indication. The objective of this study was to determine the incidence of and risk factors for QTc interval prolongation in pediatric patients treated with antipsychotics for ICU delirium.

METHODS

Retrospective chart review of pediatric patients admitted to the pediatric ICU or pediatric cardiac ICU and diagnosed with ICU delirium between October 1, 2014, and October 31, 2015. Patients were included if they received at least 1 dose of an antipsychotic for the treatment of delirium after a positive screen using the Cornell Assessment of Pediatric Delirium scoring tool.

RESULTS

For the 26 patients included, the median change in QTc interval on treatment was -4 msecs. Two patients (8%) had QTc interval prolongation while on antipsychotic therapy. No risk factors were identified in these 2 patients that put them at increased risk for QTc interval prolongation.

CONCLUSIONS

The incidence of QTc interval prolongation in pediatric patients who were treated with antipsychotics for ICU delirium was low. There is need for future research to determine which pediatric patients are at risk for QTc interval prolongation when antipsychotic medications are used for the treatment of ICU delirium.

Sudden cardiac death and antipsychotics Part 2: Monitoring and prevention

Cardiac safety of antipsychotic drugs continues to be a concern for both typical and atypical antipsychotics. Risk appears greatest in those with pre-existing cardiac disease but many patients may have occult cardiovascular disease. In addition, several drugs appear to increase the likelihood of diabetes and weight gain, which may have an additive adverse effect. On the basis of risk of sudden cardiac death and risk of QTc prolongation we suggest considering antipsychotics in two categories – higher and lower risk. Of most concern is the use of large cumulative doses of antipsychotics that are sometimes given inadvertently by different prescribers. Clinicians need to be aware how to read an ECG, and how to monitor physical parameters and interpret the significance of QTc prolongation in relation to antipsychotic prescribing. We suggest provisional guidance on antipsychotic monitoring in relation to cardiac safety but acknowledge that future studies will help clarify which antipsychotic drugs and which concomitant risk factors are most important for those with and without established cardiac disease.

Impact of Pharmacist Intervention on Electrocardiogram Monitoring of Pediatric Patients on Multiple QTc Interval-Prolonging Medications

OBJECTIVES

To determine whether dedicated pharmacy services improve the rate of electrocardiogram (ECG) monitoring in patients at risk for medication-induced QTc interval prolongation. In addition, determine how pediatric institutions currently monitor patients at risk for medication-induced QTc interval prolongation.

METHODS

A pharmacist-driven monitoring protocol to detect medication-induced QTc interval prolongation was developed using published literature. If patients were prescribed 3 or more medications known to prolong the QTc interval, they were recommended to have a baseline ECG to assess the QTc interval. If 3 or more QTc interval-prolonging medications were administered for 5 or more days, a follow-up ECG was recommended. Patients prescribed medications known to prolong the QTc interval were identified. Prior to pharmacist intervention, electronic medical records were reviewed to determine if baseline and follow-up ECGs were obtained in patients meeting criteria for monitoring. A dedicated pharmacist then prospectively reviewed charts and recommended monitoring. The rate of monitoring during the intervention and baseline period was compared. To determine current practice at pediatric institutions, a survey was distributed to pharmacists.

RESULTS

Pharmacist intervention improved the rate of ECG monitoring in patients at risk for medication-induced QTc interval prolongation from 47.8% to 100% (p = 0.0009). Of the 55 survey participants, 6 stated their institution had QTc interval monitoring procedures in place, 35 did not have any, and 3 had procedures in process.

CONCLUSIONS

Targeted pharmacist intervention improved the rate of ECG monitoring in patients at risk for medication-induced prolonged QTc interval. Our research and survey data reveal that institutions could benefit from targeted pharmacist intervention to monitor patients for medication-induced QTc interval prolongation.

Domperidone-Associated QT Interval Prolongation in Non-oncologic Pediatric Patients: A Review of the Literature

BACKGROUND

Domperidone is a prokinetic agent used to treat pediatric gastroesophageal reflux disease. Health Canada has issued warnings about an increased risk of domperidone-associated ventricular arrhythmias and sudden cardiac death. However, the supporting data referred only to adult patients; therefore, extrapolating the safety risks to pediatric patients is difficult.

OBJECTIVE

To summarize and evaluate the evidence for domperidone-associated QT interval prolongation, ventricular arrhythmias, and sudden cardiac death to determine the safety of this drug for pediatric patients.

DATA SOURCES

Two databases (MEDLINE [1946 to August 2015] and Embase [1980 to August 2015]) were searched with the following Medical Subject Headings and keywords: "domperidone", "arrhythmias, cardiac", "death, sudden, cardiac", "electrocardiography", "heart diseases", "long QT syndrome", "tachycardia, ventricular", "torsades de pointes", and "ventricular fibrillation". The search was limited to studies conducted in humans under 18 years of age and published in English.

STUDY SELECTION AND DATA EXTRACTION

Original research included in this review reported on the cardiac-related safety of domperidone in nononcologic patients under 18 years of age.

DATA SYNTHESIS

Of the 5 studies meeting the inclusion criteria (n = 137 patients), one reported a statistically significant change in the corrected QT (QTc) interval, but the clinical significance was unclear. Most of the studies reported rare occurrences of pathological QTc intervals in a limited number of patients. However, confounding factors (e.g., abnormal electrolyte level or concurrent medications) were not consistently considered. Potential bias might have been alleviated by blinding of electrocardiogram (ECG) assessors; however, this was not consistently implemented. The designs of the included studies did not allow assessment of causality. The results should be interpreted with caution.

CONCLUSIONS

Although the available evidence is limited, pathological QTc intervals were noted among a small number of infants, which supports the possibility of domperidone-associated risk of prolonged QTc interval. Because of the potential severity of QT interval prolongation, individual assessment and routine ECG monitoring should be implemented for patients receiving domperidone.

Absence of Change in Corrected QT Interval in Children and Adolescents Receiving Antipsychotic Treatment: A 12 Month Study

BACKGROUND

Prescriptions of antipsychotic drugs (AP) in children and adolescents have significantly increased in Europe as well as in the United States. However, there is limited evidence of the cardiac safety of second-generation antipsychotics (SGA) in the pediatric population.

OBJECTIVE

The aim of the study is to evaluate the cardiac side effects of SGA in children and adolescents, and how they are influenced by clinical, demographic, and treatment factors.

METHODS

This article presents a naturalistic, longitudinal, multicenter study conducted in 216 treatment-naïve or quasi-naïve children and adolescents receiving AP treatment. It analyzed the possible influence of AP treatment on variables such as corrected QT (QTc) intervals and heart rate for a period of 12 months (baseline, 3 months, 6 months, and 12 months). Differences among the three main prescribed drugs used in the sample (risperidone, quetiapine, and olanzapine) were assessed.

RESULTS

A total of 211 received one of the three most prescribed AP (quetiapine, risperidone or olanzapine). There were no significant QTc variations in the sample during follow-up (p = 0.54). There were no differences in QTc rates between the different SGA (risperidone-olanzapine p = 0.43; risperidone-quetiapine p = 0.42; olanzapine-quetiapine p = 0.23). When demographic, clinical, or concomitant treatment variables were considered, only baseline overweight correlated with QTc prolongation (p = 0.003). The heart rate in the whole sample tended to decrease during follow-up (p = 0.054). However, patients on quetiapine showed increased heart rate compared with those on risperidone (p = 0.04).

CONCLUSIONS

In this sample, SGA seem to have a safe heart side effect profile in the child and adolescent population. There was no observed mean increase in QTc or in heart rate.

Update on the safety of second generation antipsychotics in youths: a call for collaboration among paediatricians and child psychiatrists

During the past decade, a substantial increase in the use of second generation antipsychotics (SGAs) has occurred for a number of juvenile psychiatric disorders, often as off-label prescriptions. Although they were thought to be safer than older, first generation antipsychotics, mainly due to a lower risk of neurological adverse reactions, recent studies have raised significant concerns regarding their safety regarding metabolic, endocrinological and cardiovascular side effects. Aim of this paper is to update with a narrative review, the latest findings on safety of SGAs in youths. Results suggest that different SGAs may present different safety profiles. Metabolic adverse events are the most frequent and troublesome, with increasing evidences of heightened risk for type II diabetes mellitus. Results are discussed with specific emphasis on possible strategies of an active monitoring, which could enable both paediatricians and child psychiatrists to a possible prevention, early detection, and a timely management of such effects.

The In Vitro Pharmacological Profile of Drugs as a Proxy Indicator of Potential In Vivo Organ Toxicities

The potential of a drug to cause certain organ toxicities is somehow implicitly contained in its full pharmacological profile, provided the drug reaches and accumulates at the various organs where the different interacting proteins in its profile, both targets and off-targets, are expressed. Under this assumption, a computational approach was implemented to obtain a projected anatomical profile of a drug from its in vitro pharmacological profile linked to protein expression data across 47 organs. It was observed that the anatomical profiles obtained when using only the known primary targets of the drugs reflected roughly the intended organ targets. However, when both known and predicted secondary pharmacology was considered, the projected anatomical profiles of the drugs were able to clearly highlight potential organ off-targets. Accordingly, when applied to sets of drugs known to cause cardiotoxicity and hepatotoxicity, the approach is able to identify heart and liver, respectively, as the organs where the proteins in the pharmacological profile of the corresponding drugs are specifically expressed. When applied to a set of drugs linked to a risk of Torsades de Pointes, heart is again the organ clearly standing out from the rest and a potential protein profile hazard is proposed. The approach can be used as a proxy indicator of potential in vivo organ toxicities.

Canadian guidelines on pharmacotherapy for disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder, oppositional defiant disorder, or conduct disorder

OBJECTIVE

To develop evidence-based guidelines on pharmacotherapy for severe disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), or conduct disorder (CD). The guidelines assume that psychosocial interventions have been pursued but did not achieve sufficient improvement.

METHOD

A multidisciplinary consensus group used the Grading of Recommendations Assessment, Development and Evaluation approach for rating evidence quality and for grading recommendations. We conducted a systematic review of medications studied in placebo-controlled trials for treating disruptive and aggressive behaviour in children and adolescents with ADHD, ODD, or CD. We followed consensus procedures to make 1 of 4 recommendations for each medication: strong, in favour (↑↑); conditional, in favour (↑?); conditional, against (↓?); and strong, against (↓↓).

RESULTS

For children and adolescents with disruptive or aggressive behaviour associated with ADHD, psychostimulants received a strong recommendation in favour of use, while atomoxetine and alpha-2 agonists received a conditional recommendation in favour of use. If these patients do poorly with ADHD medications, the medication with the most evidence is risperidone. Risperidone also has the most evidence for treating disruptive or aggressive behaviour in the absence of ADHD. However, given risperidone's major adverse effects, it received only a conditional recommendation in favour of use. We recommended against using quetiapine, haloperidol, lithium, or carbamazepine because of the poor quality of evidence and their major adverse effects.

CONCLUSION

When severe disruptive or aggressive behaviour occurs with ADHD, medications for ADHD should be used first. Other medications have major adverse effects and, with the exception of risperidone, very limited evidence to support their use.

Determination of mesoridazine by liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic study in rats

The object of the present study was to develop and validate an assay method of mesoridazine in rat plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma samples from rats were prepared by simple protein precipitation and injected onto the LC-MS/MS system for quantification. Mesoridazine and chlorpromazine as an internal standard (IS) were separated by a reversed phase C18 column. A mobile phase was composed of 10mM ammonium formate in water and acetonitrile (ACN) (v/v) by a linear gradient system, increasing the percentage of ACN from 2% at 0.4min to 98% at 2.5min with 4min total run time. The ion transitions monitored in positive-ion mode [M+H](+) of multiple-reaction monitoring (MRM) were m/z 387>126 for mesoridazine and m/z 319>86 for IS. The detector response was specific and linear for mesoridazine at concentrations within the range 0.001-4μg/ml and the correlation coefficient (R(2)) was greater than 0.999 and the signal-to-noise ratios for the samples were ≥10. The intra- and inter-day precision and accuracy of the method were determined to be within the acceptance criteria for assay validation guidelines. The matrix effects were approximately 101 and 99.5% from rat plasma for mesoridazine and chlorpromazine, respectively. Mesoridazine was stable under various processing and/or handling conditions. Mesoridazine concentrations were readily measured in rat plasma samples after intravenous and oral administration. This assay method can be practically useful to the pharmacokinetic and/or toxicokinetic studies of mesoridazine.

Safety and pharmacokinetics of atypical antipsychotics in children and adolescents

Pediatric behavioral and affective disorders often require antipsychotic therapy, in combination with psychotherapeutic interventions, for their treatment and stabilization. Although pharmacotherapy can include either typical or atypical antipsychotics, the latter are generally preferred because of their apparently lower risk of adverse effects. Recent controlled trials have demonstrated the efficacy of some of these agents (including aripiprazole, clozapine, olanzapine, paliperidone, quetiapine, risperidone, ziprasidone) in adolescent schizophrenia and children or adolescent bipolar mania, or to treat severe aggression and self-injury in the context of autism in children and adolescents. Although few studies have systematically monitored their short- and, more importantly, long-term safety, current evidence indicates that sedation, hyperprolactinemia, and metabolic abnormalities such as excess weight gain, diabetes, and related cardiovascular effects were clinically relevant adverse effects in young patients, with the individual agents differing in their propensity to induce these effects. When prescribing antipsychotics for children and adolescents, physicians should therefore be aware of the specific adverse effect profiles and patients should be closely monitored for the short- and long-term development of adverse events. In pediatric patients, the starting dose, titration plan, and maintenance dose of antipsychotics must be based on their pharmacokinetics and metabolism, as in adults. Because there are significant individual differences in drug and active metabolite(s) pharmacokinetics and metabolism, which may be further affected by a number of confounding factors (including demographic variables, phenotype and drug interactions), therapeutic drug monitoring may be a valid tool for individualizing dosage, but its interpretation should also take account of changes in pharmacodynamic sensitivity with the development during childhood and adolescence.

Pharmacotherapy challenges in patients with first-episode psychosis

The first episode of a psychotic disorder typically occurs in late adolescence or young adulthood, a critical time of development with respect to personality, social role, education, and vocation. The first few years of psychosis appear to be a critical period during which intervention needs to be initiated before the consequences of psychosis become more severe. Early intervention is therefore crucial in maximizing outcomes. Although response rates to antipsychotic medication in first-episode psychosis (FEP) are good, there is a relatively high risk of relapse. The greatest challenges that physicians face in treating FEP and preventing relapse are engaging patients in treatment and preventing non-adherence to therapy. Overall rates of non-adherence to antipsychotic medications for FEP patients are estimated to be at or higher than 50% within the first year of treatment, suggesting that malleable factors linked to non-adherence need to be targeted in interventions provided. Factors influencing adherence can be categorized into four groups: (1) environment-related, (2) patient-related, (3) medication-related, and (4) illness-related. This paper will review the factors associated with adherence and discuss solutions to optimize engagement, adherence to medication, and treatment in order to prevent relapse. Factors like social and family support, therapeutic alliance, attitudes and beliefs toward illness and medication, insight, substance use disorders, medication efficacy, tolerability, and accessibility will be discussed. Solutions, such as early psychosis specialized services integrating psychosocial therapies and careful selection of appropriate antipsychotic medication, will be proposed.

Cardiovascular considerations of attention deficit hyperactivity disorder medications: a report of the European Network on Hyperactivity Disorders work group, European Attention Deficit Hyperactivity Disorder Guidelines Group on attention deficit hyperactivity disorder drug safety meeting

Regulatory decisions regarding attention deficit hyperactivity disorder drug licensing and labelling, along with recent statements from professional associations, raise questions of practice regarding the evaluation and treatment of patients with attention deficit hyperactivity disorder. To address these issues for the European community, the European Network for Hyperkinetic Disorders, through its European Attention Deficit Hyperactivity Disorder Guidelines Group, organised a meeting between attention deficit hyperactivity disorder specialists, paediatric cardiovascular specialists, and representatives of the major market authorisation holders for attention deficit hyperactivity disorder medications. This manuscript represents their consensus on cardiovascular aspects of attention deficit hyperactivity disorder medications. Although sudden death has been identified in multiple young individuals on attention deficit hyperactivity disorder medication causing regulatory concern, when analysed for exposure using currently available data, sudden death does not appear to exceed that of the general population. There is no current evidence to suggest an incremental benefit to electrocardiography assessment of the general attention deficit hyperactivity disorder patient. Congenital heart disease patients have an increased prevalence of attention deficit hyperactivity disorder, and can benefit from attention deficit hyperactivity disorder therapies, including medication. The attention deficit hyperactivity disorder specialist is the appropriate individual to evaluate benefit and risk and recommend therapy in all patients, although discussion with a heart specialist is reasonable for congenital heart disease patients. For attention deficit hyperactivity disorder patients with suspected heart disease or risk factor/s for sudden death, assessment by a heart specialist is recommended, as would also be the case for a non-attention deficit hyperactivity disorder patient. The identification of risk factors for sudden death should not automatically exclude the use of attention deficit hyperactivity disorder medication.

Pharmacologic management of acutely agitated pediatric patients

Acute agitation is a state of behavioral dyscontrol that requires intervention. Medications available in rapid delivery formats are frequently administered to treat acute agitation, either as a chemical restraint or on a voluntary basis. Prior to initiating treatment, the etiology of agitation must be evaluated. In choosing a medication, general pharmacologic principles should be followed. Medication should be selected based on the underlying cause in conjunction with weighing the risks, benefits, and side effects of medications. There are three classes of medications administered to children and adolescents to treat agitation: antihistamines, benzodiazepines, and antipsychotics. The most concerning short-term side effects of antipsychotics are their adverse neurologic effects, neuroleptic malignant syndrome, and prolonged corrected QT interval. Compared with typical antipsychotics, atypical antipsychotics have a more favorable short-term side effect profile.

Atypical antipsychotics for acute manic and mixed episodes in children and adolescents with bipolar disorder: efficacy and tolerability

The diagnosis of bipolar disorder (BD) in children is increasing, and often requires a comprehensive treatment plan to address a complex array of symptoms and associated morbidities. Pharmacotherapy, in combination with psychotherapeutic interventions, is essential for the treatment and stabilization of disrupted mood. Current evidence collectively demonstrates, by randomized controlled design, that atypical antipsychotics have efficacy for the treatment of acute manic or mixed symptoms in children and adolescents with BD. Additional longitudinal and biological studies are warranted to characterize the effects of atypical antipsychotics on all phases and stages of bipolar illness development in children and adolescents.

The International Society for Bipolar Disorders (ISBD) consensus guidelines for the safety monitoring of bipolar disorder treatments

OBJECTIVES

Safety monitoring is an important aspect of bipolar disorder treatment, as mood-stabilising medications have potentially serious side effects, some of which may also aggravate existing medical comorbidities. This paper sets out the International Society for Bipolar Disorders (ISBD) guidelines for the safety monitoring of widely used agents in the treatment of bipolar disorder. These guidelines aim to provide recommendations that take into consideration the balance between safety and cost-effectiveness, to highlight iatrogenic and preventive clinical issues, and to facilitate the broad implementation of therapeutic safety monitoring as a standard component of treatment for bipolar disorder.

METHODS

These guidelines were developed by an ISBD workgroup, headed by the senior author (MB), through an iterative process of serial consensus-based revisions. After this, feedback from a multidisciplinary group of health professionals on the applicability of these guidelines was sought to develop the final recommendations.

RESULTS

General safety monitoring recommendations for all bipolar disorder patients receiving treatment and specific monitoring recommendations for individual agents are outlined.

CONCLUSIONS

These guidelines are derived from evolving and often indirect data, with minimal empirical cost-effectiveness data available to provide guidance. These guidelines will therefore need to be modified to adapt to different clinical settings and health resources. Clinical acumen and vigilance remain critical ingredients for safe treatment practice.

[Pharmacotherapy in bipolar disorders during childhood and adolescence]

OBJECTIVE

Bipolar disorders during childhood and adolescence are rare, but serious and highly recurrent disorders, often associated with negative outcome. Pharmacotherapy, including Lithium, other mood stabilizers and typical antipsychotic agents, is the first-line treatment in bipolar disorders and often necessary for many months or years.

METHOD

A computerized medline-search (Pubmed) was made for prospective studies and reviews of bipolar disorder in this age-group published during the last 10 years, which were then reviewed for their relevance.

RESULTS

Despite the widespread use of substances whose efficacy for adults is well-established, there is a substantial lack of empirical data regarding the efficacy and safety in the treatment of bipolar disorder in children and adolescents. Placebo-controlled studies are very rare, and the interpretation of the existing data is complicated by the diagnostic controversy about bipolar disorder in children. Side-effects are more common in children and adolescents than in adults.

CONCLUSIONS

Combination therapy may be favoured in cases of severe and psychotic bipolar disorder. Needed are more placebo-controlled studies and long-term studies on the efficacy and safety of mood stabilizers and atypical antipsychotic agents in the treatment of children and adolescents with bipolar disorder.

Child and adolescent schizophrenia: pharmacological approaches

BACKGROUND

Childhood-onset schizophrenia is a serious, chronic and disabling illness that can significantly affect the quality of life of the affected individuals and their families. The affected children commonly show significant premorbid developmental impairment and social abnormalities that may provide an early clinical clue to pursue treatment. Until recent times, treatment approaches for childhood schizophrenia were derived from the adult population. However, given the unique developmental challenges in the pediatric population, this extrapolation may not hold true.

OBJECTIVE

This review encompasses and elaborates on the efficacy, safety and tolerability data available at present for both typical and atypical antipsychotics for treatment of childhood schizophrenia.

METHOD

A literature search was conducted on PUBMED with special emphasis on double-blind placebo-controlled studies in childhood schizophrenia. Data from similar studies presented in recent meetings were also added to the review.

CONCLUSIONS

Recent research in pediatric psychopharmacology has led to the Food and Drug Administration's approval of two atypical antipsychotics for the treatment of schizophrenia. Although data in this age group are still sparse, research in this unique population has grown over the years.

Baseline values from the electrocardiograms of children and adolescents with ADHD

BACKGROUND

An important issue in pediatric pharmacology is the determination of whether medications affect cardiac rhythm parameters, in particular the QT interval, which is a surrogate marker for the risk of adverse cardiac events and sudden death. To evaluate changes while on medication, it is useful to have a comparison of age appropriate values while off medication. The present meta-analysis provides baseline ECG values (i.e., off medication) from approximately 6000 children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Subjects were aged 6-18 years and participated in global trials within the atomoxetine registration program. Patients were administered a 12-lead ECG at study screening and cardiac rhythm parameters were recorded. Baseline QT intervals were corrected for heart rate using 3 different methods: Bazett's, Fridericia's, and a population data-derived formula.

RESULTS

ECG data were obtained from 5289 North American and 641 non-North American children and adolescents. Means and percentiles are presented for each ECG measure and QTc interval based on pubertal status as defined by age and sex. Prior treatment history with stimulants and racial origin (Caucasian) were each associated with significantly longer mean QTc values.

CONCLUSION

Baseline ECG and QTc data from almost 6000 children and adolescents presenting with ADHD are provided to contribute to the knowledge base regarding mean values for pediatric cardiac parameters. Consistent with other studies of QT interval in children and adolescents, Bazett correction formula appears to overestimate the prevalence of prolonged QTc in the pediatric population.

The QT interval and psychotropic medications in children: recommendations for clinicians

The use of psychotropic medications in children has increased significantly in the last few years. There have been several case reports of sudden death in children taking specific psychotropic medications. Fears that these deaths might have been caused by ventricular arrhythmias have been enhanced by reports of electrocardiographic abnormalities, including prolongation of the QTc interval, in patients taking these medications. Several factors including genetic susceptibility, pre-existing cardiac disease, abnormalities of drug clearance and concomitant use of other medications known to affect the QTc interval can increase the susceptibility of the heart to conduction abnormalities. This article discusses the potential of particular psychotropic drugs to prolong the QTc interval in children, and examines other factors that may contribute to conduction abnormalities. We aim to provide clear clinical recommendations for the prescription of these drugs and the monitoring of children taking them.

Psychopharmacology in pediatric critical care

Psychopharmacologic treatment in pediatric critical care requires a careful child or adolescent psychiatric evaluation, including a thorough review of the history of present illness or injury, any current or pre-existing psychiatric disorder, past history, and laboratory studies. Although there is limited evidence to guide psychopharmacologic practice in this setting, psychopharmacologic treatment is increasing in critical care, with known indications for treatment, benefits, and risks; initial dosing guidelines; and best practices. Treatment is guided by the knowledge bases in pediatric physiology, psycho-pharmacology, and treatment of critically ill adults. Pharmacologic considerations include pharmacokinetic and pharmcodynamic aspects of specific drugs and drug classes, in particular elimination half-life, developmental considerations, drug interactions, and adverse effects. Evaluation and management of pain is a key initial step, as pain may mimic psychiatric symptoms and its effective treatment can ameliorate them. Patient comfort and safety are primary objectives for children who are acutely ill and who will survive and for those who will not. Judicious use of psychopharmacolgic agents in pediatric critical care using the limited but growing evidence base and a clinical best practices collaborative approach can reduce anxiety,sadness, disorientation, and agitation; improve analgesia; and save lives of children who are suicidal or delirious. In addition to pain, other disorders or indications for psychopharmacologic treatment are affective disorders;PTSD; post-suicide attempt patients; disruptive behavior disorders (especially ADHD); and adjustment, developmental, and substance use disorders. Treating children who are critically ill with psychotropic drugs is an integral component of comprehensive pediatric critical care in relieving pain and delirium; reducing inattention or agitation or aggressive behavior;relieving acute stress, anxiety, or depression; and improving sleep and nutrition. In palliative care, psychopharmacology is integrated with psychologicapproaches to enhance children's comfort at the end of life. Defining how best to prevent the adverse consequences of suffering and stress in pediatric critical care is a goal for protocols and for new psychopharmacologic research [23,153].

Single-dose pharmacokinetics and safety of ziprasidone in children and adolescents

OBJECTIVE

The purpose of this study was to provide single-dose pharmacokinetic, safety, and tolerability data for ziprasidone in youths with tic disorder, for comparison to adult studies to discern whether ziprasidone pediatric dosing could be modeled from adult data.

METHOD

A single-dose, open-label study of ziprasidone was conducted in youths (ages 7-16 years) with Tourette's disorder or chronic tic disorder. Dosing of ziprasidone oral suspension (40 mg/mL) was weight adjusted: >60 kg, 20 mg (group 1, n = 8); 31 to 60 kg, 10 mg (group 2, n = 8); and 16 to 30 kg, 5 mg (group 3, n = 8). Patients were assessed for serum ziprasidone concentration, safety, tolerability, and electrocardiogram pre- and postdose.

RESULTS

Twenty-four patients were evaluated for safety and tolerability, and 23 were evaluated for pharmacokinetics. Regression analysis of AUC(0-infinity) and Cmax values versus weight-normalized dose showed linear, dose-related changes in ziprasidone exposure. Ziprasidone was well tolerated with frequent, although transient, somnolence. No clinically significant change from baseline was observed in Bazett's or Fridericia's corrected QT(c) interval, and change in QT(c) interval was not related to serum ziprasidone concentration.

CONCLUSIONS

Oral ziprasidone exhibited linear pharmacokinetics and dose-related exposure in youths with Tourette's disorder or chronic tic disorder, which are comparable to adult data. A single dose of ziprasidone was well tolerated without clinically significant effects on electrocardiograms collected around the time of maximum serum concentration.

Treatment-refractory schizophrenia in children and adolescents: an update on clozapine and other pharmacologic interventions

Treatment-refractory early-onset schizophrenia is a rare but severe form of the disorder associated with poor premorbid function and long-term disability. The currently available evidence suggests that clozapine remains the most efficacious treatment for the amelioration of both positive and negative symptoms of the disorder and problematic aggressive behaviors. Clozapine use in children and adolescents, however, is limited by its association with hematologic adverse events and an increased frequency of seizure activity. Further studies are needed to examine the usefulness of antipsychotic combinations and of augmentation therapies to antipsychotic medications in order to treat persistent residual psychotic symptoms in children and adolescents who have schizophrenia and who have not responded to several sequential trials of antipsychotic monotherapy.

A possible antienuretic effect of reboxetine in children and adolescents with attention deficit/hyperactivity disorder: case series

Reboxetine is a selective norepinephrine reuptake inhibitor.

OBJECTIVES

To evaluate the antienuretic effect of reboxetine in children with attention deficit and mood disorders.

METHODS

Six children aged 12-15 years with primary nocturnal enuresis and with attention deficit/hyperactivity disorder with or without other comorbid disorders were treated with reboxetine (4-8 mg/day). Monitoring of enuretic frequency was recorded at baseline and once a week for 6 weeks.

RESULTS

A statistically significant decrease in bedwetting was noted along the assessment points (p < 0.001), with the maximal change noted in the first week of treatment (p = 0.004). Reboxetine was well tolerated with minimal and transient side effects.

CONCLUSIONS

reboxetine may possess an antienuretic effect in some children with the attention deficit/hyperactivity disorder.

Six-week open-label reboxetine treatment in children and adolescents with attention-deficit/hyperactivity disorder

OBJECTIVE

This open-label study assessed the effectiveness of reboxetine, a selective norepinephrine reuptake inhibitor, in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) resistant to a previous methylphenidate trial.

METHOD

Thirty-one child and adolescent outpatients, aged 8 to 18 (mean age, 11.7; SD = 2.87) years, diagnosed with ADHD were enrolled in a 6-week open-label study. Assessments included rater-administered scales (DSM-IV ADHD Scale; Clinical Global Impressions Scale), parent-administered scales (the Abbreviated Conners Rating Scale), and self-administered-scales for the evaluation of depressive (Children's Depression Inventory) and anxiety (the Revised Children's Manifest Anxiety Scale) symptoms. Reboxetine was initiated and maintained at a dose of 4 mg/day.

RESULTS

A significant decrease in ADHD symptoms, on all scales measured, was noted. Adverse effects were relatively mild and transient. The most common adverse effects were drowsiness/sedation and gastrointestinal complaints.

CONCLUSIONS

The results of the current open-label study suggest the effectiveness of reboxetine in the treatment of ADHD in methylphenidate-resistant children and adolescents. Double-blind, placebo-, and active comparator-controlled studies are indicated to rigorously test the efficacy of reboxetine in ADHD.

Electrocardiographic changes in children and adolescents treated with ziprasidone: a prospective study

OBJECTIVE

To assess the electrocardiographic safety profile of low-dose ziprasidone (< or =40 mg/day) among pediatric outpatients treated for up to 6 months.

METHOD

This was a prospective, open-label trial involving 20 subjects with a mean age of 13.2 +/- 3.0 years. Subjects received a mean ziprasidone dose of 30 +/- 13 mg/day and were followed for 4.6 +/- 2.0 months, receiving a median of nine electrocardiograms each (range 2-11; total, 176).

RESULTS

There were statistically significant changes from baseline to peak values in heart rate, PR, and QTc intervals, but not in QRS complex width. The mean QTc prolongation was 28 +/- 26 milliseconds and not related to dose (r = 0.16, p = .07). The peak QTc of three subjects reached or exceeded 450 milliseconds; one subject experienced a 114-millisecond prolongation. There was poor agreement (kappa = 0.25) between automated and manual identification of long QTc intervals (> or =440 milliseconds).

CONCLUSIONS

These preliminary findings, occurring at doses low by current treatment standards, suggest that close electrocardiographic monitoring is warranted when prescribing ziprasidone to children, particularly at higher doses or when combined with other QTc-prolonging agents.

A review of the growing evidence base for pediatric psychopharmacology

This article provides an update of pediatric psychopharmacologic treatment evidence and focuses on six classes of medications in pediatric populations: psychostimulants, mood stabilizers, SSRIs, tricyclic antidepressants, antipsychotic agents, and other agents. The evidence is organized by disorder so that it is most useful to practicing clinicians. We begin each section with a brief introduction and summary of the findings published before January 1998. Priority is given to clinical trials that use random assignment and use of a comparison group (ie, placebo-control, head-to-head comparison, or cross-over design). Serious concerns remain about the efficacy and safety of many of these agents for use in children and adolescents. While a great progress is being made, there is clearly much work left to be done.

A Model for Evaluating Droperidol???s Effect on the Median QTc Interval

Controversy surrounds the use of the antiemetic droperidol, because of the Food and Drug Administration-imposed "black box" warning alleging that even small doses of the drug can lead to serious (even fatal) arrhythmias when it is used for antiemetic prophylaxis during the perioperative period. We used mathematical modeling of electrocardiographic QT interval data published in a peer-reviewed manuscript to evaluate the relationship between the dose of droperidol (0.1-0.25 mg/kg i.v.) and QT(c) prolongation. In comparing the calculated QT(c) values based on the logarithm model (27-63 ms), the linear model (27-67 ms) and the square-root model (36-57 ms) to the actual measured QT(c) values (37-59 ms), the square-root model provided the best simulation of the experimental findings. Other models that we evaluated included the polynomial model and various exponent models (e.g., quartic-root model, cubic-root model, square model, and cubic model). The estimated median prolongation of the median QT(c) interval produced by droperidol 0.625-1.25 mg i.v. would vary from 9 +/- 3 to 18 +/- 3 ms. Therefore, this regression analysis suggests that small "antiemetic" doses of droperidol (< or =1.25 mg) would be unlikely to produce proarrhythmogenic effects in the perioperative period.

IMPLICATIONS

Using a square-root curve fit model to evaluate the relationship between the dose of droperidol and QT(c) prolongation, small-dose droperidol (0.625-1.25 mg i.v.) would be expected to produce <30-ms prolongation of the QT(c) interval. Therefore, small "antiemetic" doses of droperidol would not be expected to produce proarrhythmogenic effects when used for prophylaxis in surgical patients.

Benefit-Risk Assessment of Atypical Antipsychotics in the Treatment of Schizophrenia and Comorbid Disorders in Children and Adolescents

Evidence on the efficacy and safety of atypical antipsychotics in children and adolescents with schizophrenia is limited. The purpose of this review is to assess the published data on the use of atypical antipsychotics in children and adolescents with schizophrenia alone and with comorbid disorders, and to establish benefit-risk guidelines for clinicians.Risperidone, olanzapine and clozapine were found to be effective in the treatment of aggression and mania. Risperidone, and possibly also olanzapine, may be the drugs of choice in children with comorbid tic disorders. Ziprasidone has some monoamine reuptake inhibition properties and may be administered as an augmenting agent in children and adolescents with schizophrenia and comorbid anxiety and mood disorders. Compared with the typical antipsychotics, the atypical drugs seem to be more effective, better tolerated and lead to better patient adherence. Importantly, the atypical antipsychotics have a lower propensity to induce extrapyramidal symptoms and a potential (shown so far only in adults) to improve cognitive function and inhibit suicidal behaviour (especially clozapine). Yet, the adverse effects associated with these agents, especially weight gain, which may also have long-term effects, can lead to non-compliance in the young population. In children and adolescents receiving clozapine, olanzapine and quetiapine (but not ziprasidone, which does not have a pro-appetite effect), particularly those with obesity or a family history of diabetes mellitus, fasting blood glucose and lipid levels must be monitored frequently. Weight gain might be better controlled when the children and their parents are properly informed about this adverse effect and diet is regulated. Another major disadvantage of the atypical antipsychotics, especially risperidone, is their association with hyperprolactinaemia, which can lead to hypogonadism-induced osteoporosis, galactorrhoea, gynaecomastia, irregular menstruation and sexual dysfunction, all seen also with typical antipsychotics. Other atypical antipsychotics, namely olanzapine and ziprasidone, have been reported to be prolactin sparing in adults, but may not be completely devoid of hyperprolactinaemic effects in children and adolescents. Thus, prolactin levels should be assessed routinely in young patients treated with atypical antipsychotics. Further, children and adolescents with hyperprolactinaemia-related effects should be switched to a prolactin-sparing agent, such as quetiapine. All atypical antipsychotics may induce sedation and they are not devoid of extrapyramidal symptoms (especially risperidone). The use of typical antipsychotics has been limited to patients who are resistant to atypical antipsychotics, intolerant to their adverse effects, or require injections or depot preparations. Further double-blind, placebo-controlled trials and long-term safety assessments are needed before definitive conclusions can be reached about the place of atypical antipsychotics in the therapeutic armamentarium of childhood-onset schizophrenia.