Clozapine for early developmental delays with childhood-onset schizophrenia: protocol and 15-month outcome

Tardive Dyskinesia with Antipsychotic Medication in Children and Adolescents: A Systematic Literature Review

BACKGROUND

Tardive dyskinesia (TD) is a persisting, and potentially irreversible, movement disorder associated with treatment with dopamine receptor antagonists. Few data are available on the risk of TD in children and adolescents treated with antipsychotic medication.

OBJECTIVE

To review the literature on incidence, risk factors, and treatment options for antipsychotic-associated TD in children and adolescents (aged < 18 years).

METHODS

Relevant articles were identified through a systematic search of Embase and Medline performed in January 2024. Methodological quality was assessed using the Newcastle-Ottawa Scale and Joanna Briggs Institute Critical Appraisal tools.

RESULTS

Thirteen studies were identified. The reported TD point prevalence was 5-20%, with higher rates in studies involving typical antipsychotics. Lower estimates (around 1%) emerged from analyses of clinical database data suggesting underdiagnosis in clinical practice. Risk factors included treatment with typical antipsychotics, higher doses, longer duration of exposure, older age, female gender, higher baseline Abnormal Involuntary Movements Scale (AIMS) scores, intellectual impairment, and perinatal complications.

CONCLUSION

Although relatively few cases have been reported in children and adolescents, TD remains a risk in this population. Individuals receiving antipsychotics should be monitored carefully for the emergence of abnormal movements. Other than dose reduction, discontinuation, or switch to a lower-risk antipsychotic, few interventions have demonstrated efficacy. The strongest evidence for pharmacological treatment is for VMAT-2 inhibitors (valbenazine and deutetrabenazine), but these drugs are not licensed for use in children. To reduce risk, antipsychotics should be prescribed only if necessary, at the minimum effective dose and for the minimum necessary duration.

Clozapine-associated pericarditis and pancreatitis in children and adolescents: A systematic literature review and pharmacovigilance study using the VigiBase database

BACKGROUND

The literature has paid very little attention to pericarditis, pericardial effusion and pancreatitis during clozapine treatment in children and adolescents.

METHODS

Cases of clozapine-associated pericarditis and pancreatitis in children were studied using searches in: 1) PubMed (June 16, 2023), and 2) the World Health Organization's pharmacovigilance database (June 1, 2022), VigiBase. VigiBase uses a logarithmic measure of disproportionality called the information component (IC).

RESULTS

The PubMed search yielded 3 clozapine-associated pericarditis cases, 1 pancreatitis case and 1 with both. VigiBase provided a significant clozapine-associated pericarditis IC = 3.6 with an IC025 = 2.9 (only 3 cases were expected while 22 were observed). VigiBase provided a significant clozapine-associated pancreatitis IC = 2.2 with an IC025 = 1.4 (only 3 cases were expected while 16 were observed). In VigiBase clozapine-associated pericarditis and pericardial effusion in youth looked similar and on a continuum with myocarditis, as myocarditis, pericarditis and pancreatitis appeared to occur mainly during clozapine titration. Combining PubMed and VigiBase we identified: 1) 29 cases of at least possible clozapine-associated pericarditis/pericardial effusion (6 probable and 23 possible) including 7 cases with and 22 without myocarditis, and 2) 17 cases of clozapine-associated pancreatitis (1 definite and 16 possible). Two of the pancreatitis cases occurred during overdoses. No fatal outcomes were found in any clozapine-associated pericarditis and pancreatitis cases.

CONCLUSIONS

Despite the lack of attention in the literature to clozapine-associated pericarditis and pancreatitis, results demonstrate that they can happen in youth, particularly during titration. Pericarditis and pancreatitis appear to be forms of clozapine-associated inflammation during dose titration.

A Systematic Review of Clozapine Concentration-Dose Ratio from Therapeutic Drug Monitoring Studies in Children and Adolescents Treated with Clozapine for Mental Disorders

BACKGROUND

Therapeutic drug monitoring of clozapine in children and adolescents has received insufficient attention. Calculation of concentration-to-dose (C/D) ratios from trough steady-state concentrations estimate drug clearance.

METHODS

A systematic electronic literature search was conducted in 3 article databases from inception until January 10, 2023, and articles reporting clozapine concentrations in children and adolescents were retrieved. The pharmacokinetic quality of the studies was assessed, and clozapine C/D ratios were calculated using the sample mean clozapine dose and concentration.

RESULTS

Of the 37 articles of potential interest, only 7 reported clozapine trough and steady-state concentrations. After excluding case reports and a study confounded by fluvoxamine, 4 studies on psychosis from Europe and the United States were included. The clozapine C/D ratios were similar to published adult values and ranged from 0.82 to 1.24 with a weighted mean of 1.08 ng/mL per mg/d. The weighted means were 334 mg/d for the dose and 380 ng/mL for the concentration. The stratified analysis of the weighted mean clozapine C/D ratios from 2 studies showed lower values in 52 male (1.05 ng/mL per mg/d) than in 46 female (1.46 ng/mL per mg/d) children and adolescents, with values similar to those reported for European adult nonsmokers. Two female adolescents had high clozapine C/D ratios (2.54 ng/mL per mg/d), an Asian American patient with borderline obesity and a patient with intellectual disability with low dosage (mean = 102 mg/d) and concentration (mean = 55 ng/mL).

CONCLUSIONS

Reports on clozapine therapeutic drug monitoring in children and adolescents are limited in number and quality. Future studies should focus on basic pharmacokinetic issues, such as stratification by sex, smoking, and relevant comedications with inductive or inhibitory properties.

Clozapine-induced myocarditis in children and adolescents: a pharmacovigilance study using VigiBase and a systematic literature review

INTRODUCTION

Clozapine-induced myocarditis in children (age ≤18 yo) was studied from a PubMed search (18 July 2022) (9 cases) and from the World Health Organization's pharmacovigilance database, called Vigibase, of adverse drug reaction (ADR) reports (72 non-duplicated cases). VigiBase uses a logarithmic measure of disproportionality called the information component (IC). A logistic regression model of presence/absence (40/32) of seriousness in VigiBase was developed.

AREAS COVERED

VigiBase provided a significant myocarditis IC = 4.2 with an IC₀₂₅ = 3.8; only 4 clozapine-induced myocarditis cases were expected, while 72 were observed. The PubMed search identified 9 cases, while VigiBase identified 72 cases (of which 67 did not overlap with published cases). These 76 combined cases included 35 doubtful (most with missing information on the day of diagnosis), 19 possible and 22 probable, according to the ADR scale. After adjusting for confounders, quetiapine increased the risk of seriousness with an odds ratio (OR) of 17.6 (95% confidence interval CI, 1.56 to 198.6), while Australian origin decreased it with an OR = 0.13 (CI, 0.04 to 0.47).

EXPERT OPINION

These 41 cases of at least possible clozapine-induced myocarditis indicated that this ADR can definitively occur in children, particularly in the first 30 days of up-titration. Children's and adult cases appeared similar.

Clozapine for Management of Childhood and Adolescent-Onset Schizophrenia: A Systematic Review and Meta-Analysis

Background: Schizophrenia at a young age deserves investigation because of the greater severity and burden of illness on individuals and health care than its adult onset. For this study, we included both childhood-onset schizophrenia and early-onset schizophrenia. We used the common term "childhood and adolescent-onset schizophrenia (CAOS)" for either type. This systematic review provides an overview of the clinical use, efficacy, and safety of clozapine treatment in managing CAOS. Methods: We conducted a systematic literature search in PubMed, Embase, and PsycINFO databases. We searched for randomized controlled trials (RCTs), open-label studies (OLSs), review articles, meta-analytic and observational studies. Our literature search resulted in 1242 search results. After the title, abstract, and full article review, 18 studies qualified (double-blind RCTs n = 4; OLS n = 4; observational studies n = 7; case reports n = 3). Results: Clozapine use in CAOS was generally well tolerated and not associated with any fatalities. Clozapine use in the short term (6 weeks) and long term (2-9 years) was superior in efficacy than other antipsychotics in CAOS management. Improvement in overall symptoms was maintained during long-term follow-up over the years in OLSs. Clozapine appeared to have a favorable clinical response and shorter hospital stays. Sedation and hypersalivation were commonly reported (90%), constipation was next in frequency (13%-50%). Neutropenia was seen in 6%-15% of cases and agranulocytosis (<0.1%). Although weight gain was common (up to 64%), followed by metabolic changes (8%-22%), treatment-onset diabetes was less frequent (<6%). Akathisia, tachycardia, and blood pressure changes were less commonly seen. Conclusions: Limited studies indicate that clozapine is a safe and efficacious option for CAOS management. We need large-scale and well-designed long-term RCTs for the use of clozapine in the management of CAOS.

Clozapine for psychotic disorders in adults with intellectual disabilities

BACKGROUND

Psychosis is three times more common in people with an intellectual disability than in those without an intellectual disability. A low intelligence quotient (IQ) is a defining characteristic for intellectual disability and a risk factor for poor outcome in psychosis. Clozapine is recommended for treatment-resistant psychosis. The effect of psychotropic medication can be different in people with intellectual disability; for example, they may be more prone to side effects. People with an intellectual disability and psychosis form a special subgroup and we wanted to examine if there is randomised controlled trial (RCT) data in this population to support the use of clozapine.

OBJECTIVES

To determine the effects of clozapine for treating adults with a dual diagnosis of intellectual disability and psychosis.

SEARCH METHODS

We searched CENTRAL, Ovid MEDLINE, Embase and eight other databases up to December 2014. We also searched two trials registers, the Cochrane Schizophrenia Group's Register of Trials, and contacted the manufacturers of clozapine.

SELECTION CRITERIA

RCTs that assessed the effects of clozapine, at any dose, for treating adults (aged 18 years and over) with a dual diagnosis of intellectual disability and psychotic disorder, compared with placebo or another antipsychotic medication.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened all titles, abstracts and any relevant full-text reports against the inclusion criteria.

MAIN RESULTS

Of the 1224 titles and abstracts screened, we shortlisted 38 full-text articles, which we subsequently excluded as they did not meet the inclusion criteria. These studies were not RCTs. Consequently, no studies are included in this Cochrane review.

AUTHORS' CONCLUSIONS

There are currently no RCTs that assess the efficacy and side effects of clozapine in people with intellectual disabilities and psychoses. Given the use of clozapine in this vulnerable population, there is an urgent need for a RCT of clozapine in people with a dual diagnosis of intellectual disability and psychosis to fill the evidence gap.

Clozapine and tardive movement disorders: a review

BACKGROUND

Tardive syndromes (TS) arise from long term exposure to dopamine receptor blocking agents. Clozapine has been considered to have low risk of causing new onset TS and is considered as a treatment option in patients with TS.

AIM

This review evaluates the usefulness of clozapine in patients with TS and occasional reports of clozapine causing TS.

METHODOLOGY

Electronic searches were carried out using the search engines of PUBMED, Science direct and Google Scholar databases. All reports describing use of clozapine in management of TS, monitoring of TS while on clozapine and onset of TS after initiation of clozapine were identified.

RESULTS

Fifteen trials and 28 case series/case reports describe the use of clozapine in TS. Most of these reports show that clozapine is useful in patients with TS, in the dose range of 200-300 mg/day and the beneficial effect is seen within 4-12 weeks of initiation. One case series and two case reports described clozapine withdrawal emergent dyskinesias suggesting a masking role of clozapine. One trial, three case series and two case reports describe beneficial effects of clozapine on long standing neurological syndromes. There is relatively less literature (2 trials and 15 case series/reports) describing the emergence of TS with clozapine.

CONCLUSION

Evidence of beneficial effects of clozapine in TS is greater than its role in causation/worsening of TS. Hence, clozapine should be considered in symptomatic patients who develop TS while receiving other antipsychotics. Further research on mechanism of TS and clozapine effect on TS is required.

Treatment of early onset schizophrenia: recent trends, challenges and future considerations

Early onset schizophrenia (onset before adulthood) is a rare, severe, and chronic form of schizophrenia. The clinical presentation of schizophrenia at this unusually early age of onset has been associated with premorbid developmental abnormalities, poor response to neuroleptic treatment, greater admission rates, and poor prognosis. This is a brief, condensed review of current treatment strategies for the early onset population highlighting the need for novel treatment strategies for these generally treatment-refractory cases. Based on the current literature, second-generation antipsychotics remain the mainstay of treatment, although current medications provide suboptimal response at best. Based on the adult literature, combining antipsychotic treatment with psychotherapeutic intervention may be a more comprehensive treatment strategy. Indeed, early detection, identification of relevant biomarkers, coupled with advancing knowledge of the neurochemical and neuroanatomic pathways may help design informed and novel treatment strategies.

Clozapine use in children and adolescents

BACKGROUND

Although the role of clozapine is well established for treatment-resistant schizophrenia, it is rarely used in pediatric populations, mainly due to its potentially serious adverse effects.

OBJECTIVE

To summarize practical aspects of use of clozapine in treating children with schizophrenia and management of associated adverse effects.

METHODS

Available studies in the literature using clozapine in the pediatric population are summarized and the NIMH experience in treating refractory childhood-onset schizophrenia cases with clozapine is discussed.

CONCLUSION

Despite a higher incidence of adverse effects in children, clozapine appears to be a uniquely beneficial second-line agent for treating children with refractory schizophrenia.

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.

Second-generation antipsychotic medications in children and adolescents

OBJECTIVE

We reviewed available pediatric literature on second-generation antipsychotic medications to assess current evidence of efficacy and safety.

METHOD

An English language MEDLINE search (1974-2003) was conducted using key words-atypical antipsychotics, children and adolescents, toxicity, clozapine, risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole. Additional efficacy and safety data were obtained from drug manufacturers.

RESULTS

We identified 176 reports, including 15 double-blind, controlled trials, 58 openlabel studies, 18 retrospective chart reviews, and 85 case series/reports. The majority of these studies (43%) were of risperidone. Evidence suggests that second-generation antipsychotics are efficacious in the treatment of psychosis, bipolar disorders, pervasive developmental disorders, and Tourette's Disorder, and are potentially useful in mental retardation, conduct disorder, and severe attention deficit hyperactivity disorder (ADHD). The most frequently reported side effects included cardiovascular effects, weight gain, sedation, sialorrhea, extrapyramidal signs, and hyperprolactinemia, although the relative frequencies of these untoward effects vary among medications.

CONCLUSION

Although the evidence base for pediatric use of second-generation antipsychotics is expanding, the majority of available studies are anecdotal, or short-term, openlabel trials. Reports suggest that these compounds are effective for a variety of psychiatric disorders in children and adolescents, but additional double-blind, controlled studies are required to establish definitive efficacy. Although these medications appear to be well tolerated in short-term studies, long-term follow-up investigations and ongoing clinical monitoring are necessary to confirm their safety in this age group.

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.

Tolerability profile of atypical antipsychotics in children and adolescents

Antipsychotics are frequently used in the treatment of a variety of neuropsychiatric conditions in children and adolescents. Atypical antipsychotics have come to the forefront in child psychiatry due largely to their tolerability profiles as well as their efficacy. Potential treatment options include clozapine, risperidone, olanzapine, quetiapine and ziprasidone. A number of studies investigating the use of clozapine have been published in children; however, owing to the frequent monitoring required for agranulocytosis, the use of clozapine may be restricted to patients with treatment-refractory disease. With accumulating data on the development of glucose intolerance in adults receiving clozapine, closer monitoring of bodyweight and fasting blood glucose is imperative. Clozapine also has an increased seizure risk, therefore a baseline electroencephalogram should be performed, as well as continued vigilance for this adverse effect. Risperidone is an atypical antipsychotic that is generally well tolerated and numerous studies have been published investigating this drug in children. Unlike clozapine, its receptor interaction profile lends itself toward increased risk of extrapyramidal symptoms (EPS) and hyperprolactinaemia. Bodyweight gain is a common adverse effect, although somewhat less than that reported with olanzapine. Baseline liver function studies prior to initiation of this medication are recommended. Risperidone-induced mania has been reported in adults and, therefore, increased caution should be used when deciding to treat children and adolescents with risperidone, particularly in those with a predisposition toward mania. Olanzapine, like risperidone, has also been associated with onset of mania in adults. Olanzapine has a receptor profile that results in significant risk for bodyweight gain and sedation. Furthermore, this drug has been linked to the development of glucose intolerance; thus, it is important to monitor bodyweight and fasting blood glucose on a frequent basis. Less information is known about quetiapine in children and adolescents. Reports about its efficacy and tolerability vary. Quetiapine appears to have increased risk for sedation and bodyweight gain, albeit less than that of olanzapine. The compound appears to be less likely to induce EPS. Finally, ziprasidone has recently been approved for use in the adult population. This compound, in terms of its receptor profile, has more in common with risperidone. This suggests a potential for increased risk of EPS and hyperprolactinaemia. It also has an increased risk of QTc prolongation; thus, a baseline electrocardiogram is suggested, particularly in those patients with a history of cardiovascular illness. Lack of evidence for bodyweight gain with ziprasidone is a considerable advantage.

Paediatric uses of atypical antipsychotics

Antipsychotics are commonly prescribed to children and adolescents. With the relatively recent availability of the atypical antipsychotics, physicians have begun prescribing these agents to young people in the hope of finding safe, effective alternatives to the typical antipsychotics. This report reviews what is currently known about the use of the atypical antipsychotics in young people. Most of the currently available data are based on case reports and case series. The results of only a handful of prospective trials pertaining to the use of the atypical antipsychotics in youths have been reported. Based on the available information, it appears that clozapine has a role in juvenile treatment resistant schizophrenia. When considered as a group, the 'first-line' atypical antipsychotics risperidone, olanzapine and quetiapine appear to have promise as treatments for several neuropsychiatric disorders in young people. These conditions include psychotic, mood, disruptive, movement and pervasive developmental disorders. Unfortunately, as has historically been the case, the demand to address the clinical needs of young patients with neuropsychiatric disorders has outpaced empirically based information. This is particularly important because significant side effects can occur when children or adolescents are treated with atypical antipsychotics. Since there is a paucity of short-term and almost no long-term safety data pertaining to these agents in young people, careful consideration must be made prior to initiating atypical antipsychotic treatment for a child or teenager. Based upon what is known about these agents, a rational approach to the use of these drugs in juveniles is offered.

Management of schizophrenia in children and adolescents. The role of clozapine

Clozapine is a dibenzodiazepine derivative with established antipsychotic efficacy in adult patients with schizophrenic psychoses. There are more than 15 studies that have also demonstrated the antipsychotic efficacy of clozapine in childhood and adolescent schizophrenia. The main advantages of clozapine treatment in this age group in comparison with typical antipsychotics are: (i) high antipsychotic efficacy during an acute schizophrenic episode; (ii) better improvement in chronic cases with a high load of negative symptoms; and (iii) markedly fewer extrapyramidal adverse effects and, therefore, fairly good tolerability. However, because of its possible adverse effects on the haemopoetic system (granulocytopenia, agranulocytosis), clozapine should not be used as first-line antipsychotic medication. Other adverse effects are related to the cardiovascular system (hypotonia, tachycardia or arrhythmia), the central nervous system (epileptic seizures, fever) and liver function (transient increases in levels of hepatic transaminases). Two other frequent adverse effects are hypersalivation and body-weight gain, which may present a particular problem in adolescents and young adults. Careful monitoring of haematological parameters and other adverse effects are preconditions for a successful treatment programme.

Typical and atypical antipsychotics in adolescent schizophrenia: efficacy, tolerability, and differential sensitivity to extrapyramidal symptoms

OBJECTIVE

To review the existing literature on the efficacy and tolerability of antipsychotics for adolescent psychosis. The review focuses in particular on literature regarding adverse effects that are thought to have an increased incidence in young patients and on the possible neurobiological bases for such differential sensitivity.

METHOD

Pertinent studies were sought using Medline searches, supplemented by selected bibliographies, and reviewed.

RESULTS

There is a relative paucity of research in this area; in particular, well-controlled trails are lacking. The existing literature suggests fairly good efficacy of both typical and atypical antipsychotics in the treatment of psychotic disorders in children and adolescents. However, the incidence of certain side effects, particularly extrapyramidal symptoms (EPS). is found to be higher in younger patients compared with adults. Positron emission tomography (PET) receptor studies in adults have demonstrated that the incidence of EPS is related to dose-dependent dopamine type-2 (D2) receptor occupancy and that there is a significant relationship between the number of these receptors and age.

CONCLUSIONS

Improved tolerability is leading to the increasing us of atypical antipsychotics for adolescent patients, though these new drugs to have specific adverse effects of their own. There is a need for more controlled studies of atypical antipsychotics in children and adolescents. In particular, dose-finding studies are needed to determine the optimal dose range to produce the greatest improvement with the least side effects for each of these drugs.

Childhood-onset schizophrenia: an open-label study of olanzapine in adolescents

OBJECTIVE

Olanzapine, a potent 5-HT2a/2c, dopamine D1D2D4 antagonist with anticholinergic activity, has a profile of known receptor affinity similar to that of clozapine. This pilot study examined the efficacy of olanzapine for treatment-refractory childhood-onset schizophrenia in eight patients who had received 8-week open-label trials. For comparison, data are included from 15 patients who had received 6-week open-label clozapine trials using identical rating instruments (largely by the same raters) in the same treatment setting.

METHOD

Twenty-three children and adolescents with an onset of DSM-III-R schizophrenia by age 12 for whom at least two different typical neuroleptics had been ineffective participated in the two separate studies. Some of the patients were intolerant of clozapine, although it had been effective (n = 4). Patients receiving olanzapine were evaluated over 8 weeks with the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, and the Clinical Global Impressions Scale for Improvement.

RESULTS

For the eight patients who received olanzapine trials, at week 8 there was a 17% improvement in the BPRS total score, a 27% improvement in the Scale for the Assessment of Negative Symptoms, and a 1% improvement in the Scale for the Assessment of Positive Symptoms, relative to "ideal" admission status on typical neuroleptics. In contrast, the magnitude of the effect sizes for each of the clinical ratings was larger at week 6 of the previous clozapine trial than for an 8-week olanzapine trial, relative to admission status on typical neuroleptics. For the four children who had received both clozapine and olanzapine, BPRS total scores were significantly lower at week 6 of clozapine treatment compared with week 6 of olanzapine treatment (p = .03).

CONCLUSION

These data provide preliminary evidence for the efficacy of olanzapine for some children and adolescents with treatment-refractory schizophrenia, but they also suggest the need for a more rigorous double-blind comparison of these two atypical antipsychotics.

Blood biogenic amines during clozapine treatment of early-onset schizophrenia

The aims of this investigation were to evaluate long-term and short-term effects of clozapine-treatment on plasma biogenic amines and psychopathology measures in adolescents with schizophrenia (DSM-III-R criteria). The long-term study was conducted in a study sample of 40 young patients (age 14-22 years) following a mean of 3.4 years of neuroleptic treatment. During the study, 20 patients received clozapine, and the other 20 patients were treated with standard neuroleptic medications. At the beginning of the open clinical trials, the patients had already been receiving clozapine treatment for 24 +/- 15 months. Assessment of the biochemical and psychopathological measures was performed on six occasions at consecutive 6-week intervals during maintenance treatment with clozapine or conventional neuroleptics. Blood levels of serotonin, 3-methoxy-4-hydroxy-phenylglycol (MHPG), norepinephrine, and epinephrine were significantly higher in clozapine-treated patients than in conventionally treated patients. During long-term treatment, higher serotonin levels were associated with significantly fewer negative symptoms of schizophrenia, whereas higher MHPG levels were correlated with less depression. The short-term effects of clozapine were assessed in a second and independent study sample. After failing on conventional neuroleptics in clinical trials lasting a mean of 1.6 years, 15 inpatients (aged 11-20 years) received clozapine. Weekly ratings of psychopathological symptoms using standard rating scales were performed in parallel to blood samplings for measurements of biogenic amines and serum levels of clozapine. These measures were obtained for 6 weeks during conventional neuroleptic treatment and for 6 weeks during the open-label clozapine trial. Serum levels of serotonin and plasma norepinephrine levels were significantly higher during treatment with clozapine than during pretreatment with typical neuroleptics. A comparison of plasma epinephrine levels in responders (n = 7) and nonresponders (n = 8) to clozapine revealed that response to clozapine can be predicted by epinephrine levels prior to initiation of treatment with clozapine (responders ranging from 32.2 to 90.3 pg/ml; nonresponders ranging from 92.5 to 473.5 pg/ml). Additionally, subjects who responded to clozapine showed increased mean plasma concentrations of MHPG and epinephrine during treatment with this drug in comparison to the levels measured during pretreatment with typical neuroleptic medication. Nonresponders to clozapine failed to show this increase. Finally, in responders to clozapine a negative linear relationship between negative symptoms of schizophrenia and the concentrations of plasma norepinephrine and serum serotonin were observed. In conclusion, our results demonstrate that plasma epinephrine levels prior to initiation of clozapine therapy predict response to this atypical neuroleptic. Our findings derived from short-term and maintenance treatment with clozapine suggest involvement of norepinephrine, epinephrine and serotonin in the therapeutic actions of the atypical neuroleptic clozapine.

Clozapine in the treatment of a young adolescent with schizophrenia

Although recent reports have suggested that clozapine may be efficacious in the treatment of adolescents with schizophrenia, few studies have examined the use of clozapine in patients younger than 17 years of age. We describe highly successful trials of clozapine conducted in a 13-year-old girl and her cousin, both of whom developed severe symptoms of schizophrenia, which were refractory to neuroleptic medication, at the ages of 11 and 13 years, respectively. The pharmacology of and clinical experience with clozapine are reviewed.