Clozapine-induced neutropenia in children: management with lithium carbonate

Risks and benefits of clozapine and lithium co-prescribing: A systematic review and expert recommendations

OBJECTIVES

To identify the risks and benefits of clozapine‑lithium co-prescription.

METHODS

Articles published in English or French were identified with a MEDLINE, Web of Sciences and PsycINFO search, from inception through January 2023, using the term 'clozapine' in combination with 'lithium'. Data were synthesized narratively.

RESULTS

Of the 67 articles included in the review, more than half (n = 38, 56.7 %) were focused on clozapine-related blood dyscrasia. A body of evidence drawn from case reports and retrospective chart studies highlights the potential benefits of lithium prescription for clozapine-related neutropenia, since this strategy may avoid clozapine discontinuation or allow its rechallenge. The most documented adverse drug reactions (ADRs) associated with clozapine‑lithium co-prescription are neurotoxic events, which may be prevented or detected early by clinical, electroencephalographic and therapeutic drug monitoring. Causality assessment cannot be established for other reported ADRs occurring during clozapine‑lithium co-prescription. The benefits of the combined prescription on psychotic and/or mood symptoms are poorly documented.

CONCLUSION

The risks and benefits of clozapine‑lithium co-prescription require further exploration as the combination might significantly contribute to reducing underprescription or premature discontinuation of clozapine.

Long-Term Effects of Lithium Use on Children and Adolescents: A Retrospective Study from Turkey

Background: The aim of this study was to evaluate the long-term effects of lithium treatment on white blood cell (WBC) count, serum creatinine, and thyroid-stimulating hormone (TSH) levels in children and adolescents with bipolar disorder (BD) and non-BD in a Turkish children and adolescent sample. Methods: The study is based on retrospective chart review. Children and adolescent patients with BD and non-BD prescribed lithium in a mental health and neurological disorders hospital between 2012 and 2017 were included in the study. Data were collected from the electronic medical files. Laboratory values for WBC count, serum creatinine, and TSH levels at baseline within the week before the onset of lithium, and at 1st, 3rd, 6^th, and 12th month of treatment were recorded. Results: A total of 143 patients (82 females, 61 males; 100 BD, 43 non-BD) aged 9-18 were included. Non-BD diagnoses were psychotic and schizoaffective disorders, unipolar depression, attention-deficit/hyperactivity disorder, conduct disorder, severe mood dysregulation syndrome, borderline personality disorder, and autism. Mean age of the participants were 15.90 ± 1.16 years for the bipolar group and 14.88 ± 1.79 years for the nonbipolar group. Patients with BD reported more adverse effects. There was a statistically significant increase in WBC counts and TSH levels at any time point. A statistically significant elevation in serum creatinine was found at 3rd and 12th month of treatment. During the course of lithium treatment, WBC counts exceeded 13,000 in 14 (9.8%) patients, and TSH levels exceeded 5.5 mU/L in 41 patients (28.6%). Twenty-one (14.68%) patients were started on thyroxin replacement. Basal TSH levels and duration of the lithium treatment were higher in the participants with TSH levels exceeding 5.5 mU/L. Lithium maximum dose, lithium blood level, basal TSH level, and duration of treatment were higher in the participants receiving thyroxin replacement. No patients had serum creatinine levels exceeding the normal reference values. Conclusion: Our study suggests that lithium is a generally safe and tolerable agent for children and adolescents with BD and non-BD; however, close monitoring of thyroid functions particularly in patients with a higher basal TSH level and longer duration of lithium use is important.

Clozapine-associated severe eosinophilia following lithium rebound neutropenia: A case report

Background

Clozapine use is complicated by an increased risk of hematological adverse effects such as neutropenia and, rarely, eosinophilia.

Case presentation

We present the case of a 48‐year‐old man with treatment‐resistant schizophrenia. On day 12 after clozapine initiation, he had a cough with a temperature of 39.8°C. On day 16, his leukocyte count had increased to 9320 cells/mm³ (neutrophils 7550 cells/mm³ and eosinophils 680 cells/mm³). We discontinued lithium because of neutrophilia and damage to renal function on day 20. His eosinophil count increased until day 29, reaching 6750 cells/mm³. We suspected a drug‐induced reaction and discontinued clozapine on day 30. His eosinophil count gradually decreased, reaching the normal range by day 40. However, his leukocyte and neutrophil counts also gradually decreased to below than the normal range by day 40. His leukocytes and neutrophil counts had recovered by day 55.

Conclusion

We concluded that this patient had clozapine‐associated severe eosinophilia following lithium rebound neutropenia.

The eosinophil count increased reaching 6750 cells/mm³ with bronchitis and hepatitis during clozapine treatment. The leukocyte and neutrophil counts gradually decreased to below than the normal range by day 40 after discontinuation of lithium.

Factors related to lithium blood concentrations in Chinese Han patients with bipolar disorder

Background: The goal of this study was to identify the physiological factors related to the blood concentration of lithium in Chinese Han patients with bipolar disorder (BD). Materials and methods: A total of 186 Chinese Han patients with BD were assessed. Patients were recruited from the Anhui Mental Health Center. The concentrations of serum lithium were measured by a Dimension RxL Max biochemistry analyzer. Physiological factors, including body weight, body mass index (BMI), and routine laboratory parameters, were collected. Relationships between the serum lithium concentration and relevant clinical data were analyzed by Pearson correlation tests, and the independent relationships were determined by multivariate linear regression analysis. Results: Pearson correlation analysis showed that serum lithium concentrations were positively correlated with creatinine concentrations (r=0.147, P=0.046), Mg²⁺ concentrations (r=0.151, P=0.04), and the percentage of neutrophils (r=0.178, P=0.015) and negatively correlated with high-density lipoprotein (HDL) concentrations (r=-0.142, P=0.05), apolipoprotein A1 concentrations (r=-0.169, P=0.02), and Na⁺ concentrations (r=-0.148, P=0.046) in 186 patients with BD. Furthermore, multivariate linear regression analysis showed that serum lithium concentrations were negatively associated with Na⁺ concentrations and positively associated with the percentage of neutrophils. Conclusion: These results suggest that physiological factors, including creatinine, HDL, apolipoprotein A1, Na⁺, and Mg²⁺ concentrations and percentage of neutrophils, might be related to serum lithium concentrations and provide a basis for parameter selection of lithium population pharmacokinetics in Chinese Han patients with BD.

Management of common adverse effects of antipsychotic medications

The benefits of antipsychotic medications are sometimes obscured by their adverse effects. These effects range from relatively minor tolerability issues (e.g., mild sedation or dry mouth) to very unpleasant (e.g., constipation, akathisia, sexual dysfunction) to painful (e.g., acute dystonias) to disfiguring (e.g., weight gain, tardive dyskinesia) to life-threatening (e.g., myocarditis, agranulocytosis). Importantly, adverse effect profiles are specific to each antipsychotic medication and do not neatly fit into first- and second-generation classifications. This paper reviews management strategies for the most frequent side effects and identifies common principles intended to optimize net antipsychotic benefits. Only use antipsychotics if the indication is clear; only continue antipsychotics if a benefit is discernible. If an antipsychotic is providing substantial benefit, and the adverse effect is not life-threatening, then the first management choice is to lower the dose or adjust the dosing schedule. The next option is to change the antipsychotic; this is often reasonable unless the risk of relapse is high. In some instances, behavioral interventions can be tried. Finally, concomitant medications, though generally not desirable, are necessary in many instances and can provide considerable relief. Among concomitant medication strategies, anticholinergic medications for dystonias and parkinsonism are often effective; beta-blockers and anticholinergic medications are useful for akathisia; and metformin may lead to slight to moderate weight loss. Anticholinergic drops applied sublingually reduce sialorrhea. Usual medications are effective for constipation or dyslipidemias. The clinical utility of recently approved treatments for tardive dyskinesia, valbenazine and deutetrabenazine, is unclear.

Managing clozapine-induced neutropenia with lithium

Aims and Method

To review the efficacy and safety of lithium augmentation for the management of clozapine-induced neutropenia. Medline search January 1966 to March 2004.

Results

The ability of lithium to increase the white cell count (WBC) is well documented. A small number of published case reports of the successful treatment of clozapine-induced neutropenia with lithium were identified. Lithium does not protect against agranulocytosis.

Clinical Implications

Lithium may be useful in raising the WBC in patients whose baseline count is too low to allow treatment with clozapine to start and to protect against clozapine-induced neutropenia, thus allowing more patients to benefit from treatment with clozapine. It does not protect against agranulocytosis. There is no way of identifying patients whose neutropenia will progress to agranulocytosis. Careful monitoring is essential. Lithium is not licensed to increase WBC. Psychiatrists should be aware of the medicolegal implications of prescribing off-label.

Prescribing antipsychotics for children and adolescents

The prescription of antipsychotic medication in children and adolescents (<18 years of age) has increased immensely for a wide range of disorders including psychoses, bipolar disorder, conduct disorder, pervasive developmental disorder and obsessive–compulsive disorder. This has led to some concerns particularly as the evidence base in some areas is not strong, and antipsychotic medication – both first generation (FGA) and second generation (SGA) – is associated with considerable side-effects. Evidence from an increasing number of randomised controlled trials (RCTs) points to therapeutic efficacy with moderate to large effect sizes. However, some RCTs have a small number of participants, are of short duration, and many are industry funded. The use of antipsychotics alongside psychosocial interventions can be recommended in certain disorders, provided there is continued, careful monitoring. It is important to note, however, that for many conditions the use of antipsychotics is not licensed in the UK.

Lithium carbonate as a treatment for paliperidone extended-release-induced leukopenia and neutropenia in a patient with schizoaffective disorder; a case report

BACKGROUND

Antipsychotic drug treatment can potentially lead to adverse events such as leukopenia and neutropenia. Although these events are rare, they represent serious and life-threatening hematological side effects.

CASE PRESENTATION

We present a case study of a patient with schizoaffective disorder in a 50-year-old woman. We report a case of paliperidone extended-release (ER)-induced leukopenia and neutropenia in a female patient with schizoaffective disorder. Initiating lithium carbonate treatment and decreasing the dose of valproic acid improved the observed leukopenia and neutropenia. This treatment did not influence psychotic symptoms.

CONCLUSION

The combination of paliperidone ER and valproic acid induces increased paliperidone ER plasma levels. Lithium carbonate was successfully used to treat paliperidone ER-induced leukopenia and neutropenia.

The use of antipsychotics in preschoolers: a veto or a sensible last option?

Recent reports have illustrated a dramatic rise in the use of antipsychotics in preschool children, medications originally designed and licensed for the treatment of adult psychotic disorders. Within this context, the current usage and the associated diagnoses are reviewed and compared with official guidelines and licensing for such use, highlighting a controversial challenge for clinicians. A review of the evidence base of the relative efficacy of such medications for a range of disorders is given. Associated safety and side effects are discussed, with compelling evidence for increased adverse events associated with use of antipsychotics in preschoolers, and neurodevelopmental hypotheses are used to guide predictions of long-term risk. An apparent gap in the literature and evidence base supporting such use and elucidating the risks and benefits leaves a challenge for clinicians and researchers and hinders the development of appropriate guidelines. Pragmatism in clinical practice, mindful of the limited evidence base that does exist and the propensity for harm, is necessary; far more research is required in this important area.

Psychopharmacologic treatment of psychosis in children and adolescents: efficacy and management

The efficacy of antipsychotic use in children and adolescents with psychosis has been shown in an increasing number of randomized controlled trials. Chronic use of second-generation and third-generation antipsychotics has the potential for significant side effects, especially metabolic syndrome. A review of the literature on side effect profiles of antipsychotic medications used in children and adolescents is provided to help clinicians develop treatment plans for their patients. Clozapine has the best efficacy of all antipsychotic medications in adults as well as children and adolescents who are treatment resistant. Guidance is provided for the management of clozapine side effects.

Treatments in context: transcranial direct current brain stimulation as a potential treatment in pediatric psychosis

Childhood-onset schizophrenia is a chronic, severe form of schizophrenia, and is typically treatment resistant. Even after optimized pharmacotherapy, a majority (over 70%) of these pediatric patients present lasting psychotic symptoms and impaired cognition, necessitating the need for novel treatment modalities. Recent work in transcranial magnetic stimulation suggests moderate efficacy in symptom reduction in adult patients with schizophrenia; however, the transcranial magnetic stimulation treatment is cumbersome for this severely ill population. Transcranial direct current stimulation may provide a safe and effective adjuvant treatment for continued residual symptoms of schizophrenia.

Risk factors for neutropenia in clozapine-treated children and adolescents with childhood-onset schizophrenia

OBJECTIVE

The purpose of this study was to retrospectively analyze rates of neutropenia and risk factors for neutropenia in hospitalized children and adolescents treated with clozapine.

METHODS

A retrospective chart review was conducted for all patients who received clozapine at any time during a hospitalization at the National Institute of Mental Health (NIMH) between 1990 and 2011. All patients satisfied screening criteria for the NIMH childhood-onset schizophrenia study, including onset of psychosis before the age of 13 years. Absolute neutrophil count (ANC) values recorded during inpatient hospitalization were extracted for 87 eligible patients with a mean age of 13.35±2.46 years at hospitalization and a mean length of stay of 117±43 days.

RESULTS

Mild neutropenia only (lowest ANC<2000/mm3 but>1500/mm3) was observed in 27 (31%) patients and moderate neutropenia (any ANC<1500/mm3) was observed in 17 (20%) patients. There were no cases of agranulocytosis or severe infection. Significant risk factors for mild neutropenia compared with no hematologic adverse effects (HAEs) were male gender (p=0.012) and younger age (p<0.001). Male gender was also a significant risk factor for moderate neutropenia compared with no HAEs (p=0.003). If a child of African American ethnicity developed neutropenia during hospitalization at all that child was significantly more likely to develop moderate neutropenia than mild neutropenia only (p=0.017). African American boys had the highest rate of moderate neutropenia at 47%. Sixteen of the 17 patients exhibiting moderate neutropenia were successfully treated with clozapine by the time of discharge; 8 of these 16 required adjunctive lithium carbonate administration to maintain ANC>2000/mm3.

CONCLUSIONS

Our study shows that the rates of neutropenia in clozapine-treated children and adolescents are considerably higher than in the adult population. Younger age, African American ethnicity, and male gender were significant risk factors. These are also risk factors for benign neutropenia in healthy children and adolescents. Despite these high rates of neutropenia, all but one of the patients with neutropenia during hospitalization were successfully discharged on clozapine.

Empirical evidence for psychopharmacologic treatment in early-onset psychosis and schizophrenia

Psychotic symptoms presenting in youth can be clinically complex and require that a child and adolescent psychiatrist use significant skill in making a diagnosis and initiating treatment. There are a number of illnesses to rule out before making a diagnosis of early-onset schizophrenia in particular. Psychosis in youth has significant associated morbidity and places high demands not only on families but also on the medical and educational systems. More effective pharmacologic and nonpharmacologic treatments for psychosis are needed. Nonpharmacologic therapies targeting relatively treatment-resistant domains of dysfunction such as neurocognition are also necessary as adjunctive treatments to our extant pharmacologic agents.

Lithium in the treatment of neutropenia

PURPOSE OF REVIEW

The capacity of lithium to induce neutrophilia and increase circulating CD34(+) cells of marrow origin has long been known. Lithium has been the object of hematological investigations for many years, but no definitive use in hematology has yet emerged.

RECENT FINDINGS

We review the evidence that lithium increases granulocyte colony-stimulating factor (G-CSF) and augments G-CSF effects, showing its potential use in stem cell mobilization and engraftment of stem cell transplantation.

SUMMARY

We suggest possible therapeutic uses of lithium in neutropenia. In bone marrow transplantation, preharvest lithium-assisted hematopoietic stem cell mobilization may be useful as well.

Age-grouped differences in adverse drug events from psychotropic medication

OBJECTIVE

This review aims to detail specific psychotropic medication treatment differences in adverse drug events (ADEs) between children, adolescents, and adults.

METHOD

A thorough data-based search of ADEs was made, augmented by findings from approved and updated U.S. Food and Drug Administration (FDA) drug labels, controlled clinical trial reports, and from FDA information on ADEs at scheduled public hearings.

RESULTS

Children were found to generally exhibit more ADEs to psychotropic medication than adolescents and adults. These ADEs primarily include altered growth velocity, rash, vomiting, dystonia, tics, affect lability, activation, metabolic blood test abnormalities, sedation, sialorrhea, and electrocardiogram irregularities.

CONCLUSION

Children have more biological vulnerabilities than older individuals, which could account for their greater rate of ADEs to psychotropic medication treatment.

Haematological toxicity of clozapine and some other drugs used in psychiatry

OBJECTIVE

To review recent work on the haematological toxicity of clozapine and some other drugs used in psychiatry concerning especially (i) the mechanism of antipsychotic-induced neutropenia/agranulocytosis, (ii) criteria for clozapine prescribing in benign ethnic neutropenia, (iii) options in the event of worrying falls in white cell count (WCC), including measures to boost WCC with or without continued clozapine administration, (iv) criteria for clozapine rechallenge in the event that treatment was suspended because of a fall in WCC and (v) safety concerns regarding clozapine in children/adolescents.

CONCLUSIONS

There remain several difficult areas, including the criteria for clozapine rechallenge. Experience has emphasised (i) the role of appropriate timing of WCC sample collection to ensure that clozapine is not withdrawn unnecessarily and (ii) the success of agents such as filgrastim in promoting rapid production of granulocytes if the situation so demands. On the other hand, the use of lithium to promote a leucocytosis has taken hold without a clear risk: benefit analysis. Be this as it may, should patients decide that they no longer wish to undergo WCC monitoring after 12 months on clozapine, cessation of monitoring is probably preferable to stopping the drug since overall mortality is decreased in patients treated with clozapine.

Treatment of early-onset schizophrenia

PURPOSE OF REVIEW

Treatment of children who develop schizophrenia in childhood and early adolescence presents unique considerations. There has been increasing attention to the importance of early intervention and whether treatment effects may be affected by brain development.

RECENT FINDINGS

Several recent trials support the use of antipsychotics for treatment of schizophrenia in children and adolescents. Clozapine shows greater efficacy in children and adolescents than it has in adults. A large-scale trial comparing a first-generation antipsychotic (molindone) with newer agents did not find significant differences in treatment response, although the newer antipsychotics were associated with more severe weight gain. Data regarding effects of antipsychotics on brain development in children and young adolescents with schizophrenia are sparse, although one report found no difference between effects of clozapine and olanzapine on cortical thickness.

SUMMARY

Although psychosocial interventions are an important adjunctive treatment, antipsychotic medications continue to be the mainstay of treatment. Careful monitoring of metabolic side effects and age-appropriate intervention is particularly important, as children and adolescents appear to be more likely to develop metabolic abnormalities such as pronounced weight gain, which may significantly impact adherence as well as lead to other health issues.

Incidence and risk for neutropenia/agranulocytosis among clozapine users: A retrospective cohort study

Abstract Objective. To estimate the incidence and the risk of neutropenia or agranulocytosis (the outcome) associated with clozapine use (the exposure), and to identify risk factors. Methods. All data were derived from the computerized hospital database. Adult psychiatric patients were identified, and 95 incident clozapine users and 884 non-clozapine users were included. Cox proportional hazards regression was used to estimate the hazards ratio (HR) of developing the outcome after clozapine use adjusted for confounders. The interaction between clozapine and valproic acid was assessed a posteriori. Results. Throughout the 24-month follow-up, the incidence of neutropenia was 6.3% in the clozapine group and 5.8% in the non-clozapine group. One agranulocytosis was found in the non-clozapine group. The HR (95% CI) for neutropenia were: clozapine 1.33 (0.54-3.25) and age . 45 years 2.99 (1.63-5.48). Lithium, as an independent protective factor, reduced the risk for neutropenia by 85% compared with patients who did not receive lithium, HR 0.15 (95% CI 0.02-1.09). Valproic acid might potentiate the clozapine-associated neutropenia (HR 5.10, 95% CI 0.70-37.12). Conclusion. Clozapine might slightly increase the risk of neutropenia in psychiatric patients. Concerning clozapine-associated neutropenia, older patients are at increased risk and use of valproic acid concurrently with clozapine should be avoided.

Adjunctive use of lithium carbonate for the management of neutropenia in clozapine-treated children

OBJECTIVE

Clozapine, a dibenzodiazepine antipsychotic, is the most effective medication for treatment-resistant schizophrenia. However, its use has been limited by the high risk of neutropenia. In children, the rate of neutropenia is higher when compared to adults. We decided to explore the use of lithium to manage neutropenia in childhood-onset schizophrenia (COS) through a systematic audit of COS cases.

METHODS

Medical records were reviewed for patients with COS who had been treated with the combination of clozapine and lithium carbonate.

RESULTS

Seven patients were found to have been treated with both clozapine and lithium. After initiation of lithium, ANC increased significantly in six out of seven subjects by 29 to 106% with a mean of 66%. In addition, six out of seven subjects continued using both clozapine and lithium for over 2 years (range: 2.0-7.2 years) and do not have immediate plans for discontinuation of either medications.

CONCLUSIONS

Our study bolsters support for the use of lithium in the management of neutropenia in children treated with clozapine. Although the coadministration of lithium and clozapine appears effective in the management of neutropenia, it is not without its risks and clinicians must be diligent in their joint use of these medications.

Review of lithium effects on brain and blood

Clinicians have long used lithium to treat manic depression. They have also observed that lithium causes granulocytosis and lymphopenia while it enhances immunological activities of monocytes and lymphocytes. In fact, clinicians have long used lithium to treat granulocytopenia resulting from radiation and chemotherapy, to boost immunoglobulins after vaccination, and to enhance natural killer activity. Recent studies revealed a mechanism that ties together these disparate effects of lithium. Lithium acts through multiple pathways to inhibit glycogen synthetase kinase-3beta (GSK3 beta). This enzyme phosphorylates and inhibits nuclear factors that turn on cell growth and protection programs, including the nuclear factor of activated T cells (NFAT) and WNT/beta-catenin. In animals, lithium upregulates neurotrophins, including brain-derived neurotrophic factor (BDNF), nerve growth factor, neurotrophin-3 (NT3), as well as receptors to these growth factors in brain. Lithium also stimulates proliferation of stem cells, including bone marrow and neural stem cells in the subventricular zone, striatum, and forebrain. The stimulation of endogenous neural stem cells may explain why lithium increases brain cell density and volume in patients with bipolar disorders. Lithium also increases brain concentrations of the neuronal markers n-acetyl-aspartate and myoinositol. Lithium also remarkably protects neurons against glutamate, seizures, and apoptosis due to a wide variety of neurotoxins. The effective dose range for lithium is 0.6-1.0 mM in serum and >1.5 mM may be toxic. Serum lithium levels of 1.5-2.0 mM may have mild and reversible toxic effects on kidney, liver, heart, and glands. Serum levels of >2 mM may be associated with neurological symptoms, including cerebellar dysfunction. Prolonged lithium intoxication >2 mM can cause permanent brain damage. Lithium has low mutagenic and carcinogenic risk. Lithium is still the most effective therapy for depression. It "cures" a third of the patients with manic depression, improves the lives of about a third, and is ineffective in about a third. Recent studies suggest that some anticonvulsants (i.e., valproate, carbamapazine, and lamotrigene) may be useful in patients that do not respond to lithium. Lithium has been reported to be beneficial in animal models of brain injury, stroke, Alzheimer's, Huntington's, and Parkinson's diseases, amyotrophic lateral sclerosis (ALS), spinal cord injury, and other conditions. Clinical trials assessing the effects of lithium are under way. A recent clinical trial suggests that lithium stops the progression of ALS.

Long-term sustained benefits of clozapine treatment in refractory early onset schizophrenia: a retrospective study in Korean children and adolescents

OBJECTIVE

Treatment resistance in early onset schizophrenia (EOS) is one of the most challenging problems in child and adolescent psychiatry. We retrospectively examined the therapeutic dosage, clinical response, and side effect profiles of long-term clozapine treatment in Korean children and adolescents with refractory EOS or very early onset schizophrenia (VEOS).

METHOD

26 refractory patients treated with clozapine for more than 1 year were analyzed. Efficacy was determined by comparing hospitalization rate and duration, before and after clozapine treatment. Tolerability was assessed through review of documented adverse events.

RESULTS

A significant reduction in hospital days per year was observed in 25 (96.2%) patients after clozapine treatment compared to before clozapine. Long-term benefit of the treatment was supported by a further reduction of the hospitalization rate in 14 patients treated with clozapine for more than 3 years. Neutropenia developed in 26.9% patients at 1 year and there was no agranulocytosis. Overall, eight male patients (8/12, 66.7%) and one female patient (1/14, 7%) developed neutropenia and out of the nine patients, seven patients were maintained and two patients were successfully rechallenged on clozapine.

CONCLUSION

These findings suggest that long-term clozapine treatment may effectively reduce the amount of time Asian patients with refractory EOS or VEOS spend in the hospital. However careful monitoring of adverse events is required.

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.

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.

Haematological toxicity of drugs used in psychiatry

Almost all classes of psychotropic agents have been reported to cause blood dyscrasias. Mechanisms include direct toxic effects upon the bone marrow, the formation of antibodies against haematopoietic precursors or involve peripheral destruction of cells. Agranulocytosis is probably the most important drug-related blood dyscrasia. The mortality from drug-induced agranulocytosis is 5-10% in Western countries. The manifestations of agranulocytosis are secondary to infection. Aggressive treatment with intravenous broad-spectrum antimicrobials and bone marrow stimulants may be required. Of drugs encountered in psychiatry, antipsychotics including clozapine (risk of agranulocytosis approximately 0.8%, predominantly in the first year of treatment) and phenothiazines (chlorpromazine agranulocytosis risk approximately 0.13%), and antiepileptics (notably carbamazepine, neutropenia risk approximately 0.5%) are the most common causes of drug-related neutropenia/agranulocytosis. Drugs known to cause neutropenia should not be used concomitantly with other drugs known to cause this problem. High temperature and other indicators of possible infection should be looked for routinely during treatment. Clozapine is well known as a drug that can cause blood dyscrasias, but olanzapine and other atypicals may also cause similar problems. In addition to genetic factors, there are likely to be dose-related and immunological components to these phenomena. Important lessons have been learnt from the haematological monitoring that is necessary with clozapine and the monitoring has been very successful in preventing deaths related to clozapine-induced agranulocytosis. Continuing research into the mechanisms of drug-induced neutropenia and agranulocytosis may serve to further enhance the safe use not only of clozapine, but also of other agents.

Clozapine-induced leukopenia successfully treated with lithium

PURPOSE

A case of clozapine-induced leukopenia successfully treated with lithium is reported.

SUMMARY

A 55-year-old man with paranoid schizophrenia who had been stable on clozapine for more than 10 years was admitted to an inpatient behavioral health unit with leukopenia associated with clozapine use. This patient's history was significant for four previous hospitalizations for psychiatric issues, none of which occurred while he was using clozapine. On admission, the patient's clozapine was discontinued and he was started on olanzapine. On hospital day 4, his white blood cell (WBC) count had risen to 3400/mm(3) and clozapine was resumed due to increasing auditory hallucinations and suicidal ideation. On hospital day 5, his WBC count decreased to 2900/mm(3) and clozapine was again stopped. The patient was given lithium carbonate 300 mg at bedtime, and olanzapine was discontinued. The next day, clozapine was restarted at 12.5 mg daily at bedtime. On hospital day 11, his WBC count had risen to 5400/mm(3). The patient was discharged on clozapine 25 mg at bedtime, with a WBC count of 3400/mm(3). The patient has not been rehospitalized and has not had significant changes in his WBC count or absolute neutrophil count (ANC) for more than 14 months.

CONCLUSION

A 55-year-old man with schizophrenia developed clozapine- induced leukopenia after more than 10 years of treatment. Lithium was used to stimulate leukocyte production, and clozapine was restarted successfully. The patient was maintained on clozapine and lithium without significant changes in his WBC count or ANC.

Restarting clozapine after neutropenia: evaluating the possibilities and practicalities

Clozapine remains the antipsychotic of choice for refractory schizophrenia despite its propensity for serious blood disorders. When neutropenia or agranulocytosis occur in people taking clozapine, cessation of treatment is mandated and relapse often results. Because such patients are usually unresponsive to other antipsychotics, many clinicians consider restarting clozapine, despite the risks involved. However, the risks of clozapine rechallenge vary according to the cause and nature of the blood dyscrasia. Neutropenia can arise because of factors unrelated or indirectly related to clozapine treatment. These include benign ethnic neutropenia, concomitant drug therapy, co-existing medical conditions and drug interactions. In such cases, clozapine may be restarted if non-clozapine causes of neutropenia are identified and eliminated, although concurrent treatment with lithium (to induce leukocytosis) is sometimes necessary. Close monitoring of the patient is essential because it is rarely possible to completely rule out the contribution of clozapine to the blood dyscrasia and because lithium does not protect against clozapine-related agranulocytosis. In cases of clozapine-induced neutropenia (as distinct from agranulocytosis, which may have a different pathology) rechallenge may also be considered and, again, lithium co-therapy may be required. Where clozapine is clearly the cause of agranulocytosis, rechallenge should not be considered or undertaken unless there are very exceptional circumstances (severe and prolonged relapse following clozapine discontinuation). In these cases, re-exposure to clozapine may rarely be attempted where there are facilities for very close and frequent monitoring. Granulocyte colony-stimulating factor is likely to be required as co-therapy, given the very high likelihood of recurrence. Uncertainty over the likely cause of blood dyscrasia in people taking clozapine, coupled with uncertainty over the mechanism by which clozapine causes both neutropenia and agranulocytosis, makes any attempt to restart clozapine a high-risk venture requiring the utmost caution.

Somatic augmentation strategies in clozapine resistance--what facts?

BACKGROUND

Polypharmacy without evidence-based support is sometimes needed for patients treated with 40% to 70% clozapine who are clozapine nonresponders. Several somatic augmentation strategies are proposed in the scientific literature, with different levels of evidence for safety and efficacy.

OBJECTIVES

The purpose of the present study is to review the available literature on the efficacy and safety of clozapine augmentation with somatic agents other than antipsychotics. The following classes of agents are considered: (1) mood stabilizers, (2) antidepressants, (3) electroconvulsive therapy and repetitive transcranial magnetic stimulation, (4) glutamatergic agents, (5)fatty acids supplements, and (6) benzodiazepines.

RESULTS

Case controls and small-size clinical trials largely dominate the literature, limiting the power to draw conclusions concerning safety issues and the meaning of negative studies. Moreover, variable definitions of clozapine resistance, heterogeneous outcome measures, and short duration of treatment trials are additional limitations.

CONCLUSION

Generally, adjunctive strategies for clozapine-resistant patients remain based on scarce evidence of efficacy and significant safety concerns. Low-frequency repetitive transcranial magnetic stimulation, fatty acids supplements, and mirtazapine showed good tolerability and some efficacy, but the results need replication.

Recognizing and monitoring adverse events of second-generation antipsychotics in children and adolescents

Although second-generation antipsychotics (SGAs) are used increasingly in children and adolescents, data on the effectiveness and safety in pediatric populations are still sparse. Much of the safety information is derived from studies conducted in adults. This derivation is problematic because children and adolescents are exposed to SGAs during a phase of unparalleled physical and psychologic development that can affect pharmacokinetic and pharmacodynamic drug actions, efficacy, and side-effect patterns. This article presents an overview of SGA-related side effects in children and adolescents and strategies to monitor health outcomes effectively in youngsters receiving SGAs.

Hematological adverse events in clozapine-treated children and adolescents

OBJECTIVE

To retrospectively examine rates of hematological adverse events (HAEs) in psychiatrically ill, hospitalized children treated with clozapine.

METHOD

Clozapine treatment was administered in an open-label fashion using a flexible titration schedule, and data from weekly complete blood counts was obtained. The rate of neutropenia and agranulocytosis (HAEs) development was determined for 172 eligible patients (mean age at clozapine initiation, 15.03 +/- 2.13 years) with a median observation period of 8 months.

RESULTS

Neutropenia (absolute neutrophil count <1,500/mm) developed in 23 (13%) patients and agranulocytosis (absolute neutrophil count <500/mm) in one (0.6%) patient. The cumulative probability of developing an initial HAE at 1 year of clozapine treatment was 16.1% (95% confidence interval 9.7%-22.5%). Eleven (48%) of 24 patients who developed an HAE were successfully rechallenged on clozapine. Eight (5%) of 172 patients from this sample eventually discontinued clozapine because of an HAE (one agranulocytosis, seven neutropenia).

CONCLUSIONS

The occurrence of HAEs is a significant risk associated with the administration of clozapine. However, in this sample, few children actually discontinued therapy because of an HAE and the incidence of agranulocytosis does not appear higher than what has been reported in the adult literature.

Continuing clozapine treatment despite neutropenia

RATIONALE

Approximately 1-2% of patients treated with the atypical antipsychotic clozapine develop severe neutropenia and agranulocytosis. The usual recommendation is to discontinue treatment with the drug when the peripheral neutrophil count drops below 1,500/mm3.

METHODS

We have reviewed several reports describing procedures that allowed the patients to continue clozapine treatment despite the occurrence of these haematological side effects.

RESULTS

The therapeutic procedures described (symptomatic treatment of neutropenia by co-administration of lithium or granulopoiesis-stimulating factors, management of the adjunctive medication) seem to be efficient strategies that allow continuation of clozapine treatment despite the occurrence of neutropenia. However, these types of therapy have only been used in a limited number of cases, and the evidence supporting their use remains anecdotal.

CONCLUSION

Although the procedures adopted in the cases described in this review are uncommon, they potentially provide an alternative to the discontinuation of clozapine treatment in patients with complex symptomatologies for whom treatment with other antipsychotic medication is insufficient.