Prevention of clozapine-induced neutropenia by pretreatment with lithium

Combination of strategies to initiate clozapine for refractory schizophrenia in a patient with low neutrophil levels

Clozapine is the only drug with confirmed efficacy for refractory schizophrenia; however, its use is restricted due to the risk of potentially life-threatening side effects, such as agranulocytosis. Although this restriction ensures safety against haematological risks, some patients with refractory schizophrenia who have low neutrophil levels may miss the opportunity to receive clozapine treatment. We herein report the case of a patient with refractory schizophrenia and low neutrophil levels who was successfully initiated on clozapine treatment after the use of several methods for increasing neutrophil levels. These strategies consisted of discontinuation of antipsychotics, treatment with lithium carbonate and adenine, and light exercise before blood testing. Combining these procedures may be an effective option in the treatment of patients with refractory schizophrenia whose neutrophil levels are not sufficient to initiate clozapine.

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.

[Clozapine rechallenge after neutropenia in resistant schizophrenia: A review]

INTRODUCTION

Clozapine is an atypical antipsychotic known for its efficacy in refractory schizophrenia. One of the adverse effects is neutropenia. This dysplasia is a rare but major side effect which leads to a discontinuation and constitutes further contraindication. Thereafter, therapeutic options decrease dramatically. Mechanisms involved are not well known at this time and can be combined. A toxic hypothesis may be more likely than an immune-allergic one.

METHODS

We have reviewed publications on Medline describing procedures that allowed clozapine rechallenge after blood dyscrasia in refractory schizophrenia. Three different procedures were found: simple rechallenge, rechallenge with lithium and rechallenge with Granulocyte - colony stimulating factor (G-CSF). Rechallenge could be simple or multiple.

RESULTS

These past years, clozapine have been rechallenged successfully after neutropenia thanks to different procedures, the different options being simple rechallenge, rechallenge with lithium and/or rechallenge with G-CSF. Lithium as G-CSF are used to increase neutrophil blood rate and prevent neutropenia recurrence after clozapine rechallenge. G-CSF was first used within the context of chemotherapy and extends now to clozapine-induced neutropenia. Both for lithium and G-CSF, numerous procedures are reviewed and cannot be compared.

DISCUSSION

Publications are limited but increasing, and they point out that a careful rechallenge can be successful. However, interesting data can be extracted. First, clozapine is more likely to be incriminated in neutropenia when patients receive many drugs, but a careful study could prevent some discontinuation. Indeed, other drugs or a hematologic disease could be involved. Moreover, several contributing factors have been found such as HLA group and drug interaction. Ethnic origin also affects neutrophil rate. That is why, in Great Britain, a subgroup of patients "benign ethnic neutropenia" has been introduced to enlarge threshold and allow these patients to access clozapine despite lower blood counts. Then, rechallenge choice has to be done on a case-by-case basis and only after considering the benefits and risks of such a treatment. Most of the time, clinical advice of rechallenge arises from the inefficiency of other antipsychotics and even sismotherapy failure. Patients and sometimes families have to be informed and give their consent. Preventive measures have been found such as taking a hematologic recommendation and doing twice-a-week blood sample monitoring. With regards lithium and G-CSF, some efficient doses are assumed (lithium: 0,4-1,1 mEq/L and G-CSF>0,3 mg/week). Lithium as G-CSF may have other adverse effects which need to be considered. There is no successful rechallenge reported after agranulocytosis. Some publications highlight that if neutropenia occurs on rechallenge, it will do so more quickly and more severe than at the time of initial trial of clozapine.

CONCLUSION

There is emerging evidence of successful clozapine rechallenging. However, further investigations are required as randomized controlled trials to reassess guidelines and establish the safety and effectiveness of the different procedures. Because of the practical and ethical difficulties of designing such studies, referral hospitals could be elected, and common background writing proposed in order to ease data comparison.

Making clozapine safer: current perspectives on improving its tolerability

ABSTRACT: 

Clozapine is the gold standard treatment for refractory schizophrenia and its benefits are supported by an evidence base. Yet, it remains largely underused in clinical practice. This is because of low acceptability from patients and reluctance in initiating, and delays in prescribing by clinicians. A major deterrent is often the common adverse reactions, which clinicians are apt to disregard, focusing instead on the severe but rare complications of clozapine, such as agranulocytosis. We will review recent evidence on increasing the prescription of clozapine, focusing particularly on improving the safety and tolerability of the drug, by effective management of its adverse effects. The adverse effects considered in our review include sedation, seizures, myoclonus, hypersalivation, nausea, constipation, hypotension, hypertension, tachycardia, myocarditis, cardiomyopathy, weight gain, diabetes, dyslipidemia, neutropenia, agranulocytosis, fever, nocturnal enuresis and obsessive–compulsive symptoms. We will also discuss strategies to enable successful clozapine rechallenge after severe cardiac and hematological adverse reactions, thus aiming to offer patients their best chance at recovery.

Management and prevention of agranulocytosis in patients receiving clozapine

Clozapine is an antipsychotic associated with superior efficacy compared to other atypical antipsychotics in the treatment of schizophrenia. However, clozapine use is limited due to its association with a rare but potentially fatal adverse effect, agranulocytosis. Patients receiving clozapine therapy require frequent monitoring of white blood cell (WBC) and absolute neutrophil counts (ANC). This article reviews the monitoring parameters for patients receiving clozapine therapy, and the management and prevention of clozapine-associated agranulocytosis.

Clozapine: key discussion points for prescribers

Clozapine is the most effective antipsychotic medication for treatment-refractory schizophrenia and is also approved for suicidality in schizophrenia patients. However, it can cause significant medical morbidity and requires intensive medical monitoring once prescribed. Perhaps due to lack of familiarity with its use, it is underused in clinical practice and its initiation often delayed. This article reviews the literature on clozapine in order to measure its potential effectiveness against its adverse effects and ultimately aims to serve as a useful summary for clinicians in their everyday prescribing.

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.

Lithium, trifluperazine and idiopathic leucopenia: Author and reviewer perspectives on how to write a good case report

BACKGROUND

The Indian Journal of Psychiatry receives many reports which, despite obvious academic worth, are too poorly written to be publishable. Such submissions tax manuscript reviewers and increase the editorial office workload without benefiting the authors with a publication.

METHODS

We describe an authentic and previously unpublished case of idiopathic leucopenia and psychosis. Leucocyte levels in this patient dropped upon challenge with different atypical antipsychotic drugs. Lithium pretreatment, however, permitted the safe and successful use of trifluperazine. Readers are invited to use a roughly-prepared version of the case report to draft a submission-worthy manuscript.

RESULTS

Two versions of the manuscript are presented. The first version is generally satisfactory but will trigger several queries during peer review; these queries are indicated. The second version would be considered acceptable by most reviewers.

CONCLUSIONS

Readers who work through the exercise provided in this article will better understand how authors should prepare their report and how reviewers may scrutinize their manuscript.

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.

Adverse effects of atypical antipsychotics : differential risk and clinical implications

Antipsychotic drugs can be of great benefit in a range of psychiatric disorders, including schizophrenia and bipolar disorder, but all are associated with a wide range of potential adverse effects. These can impair quality of life, cause stigma, lead to poor adherence with medication, cause physical morbidity and, in extreme cases, be fatal. A comprehensive overview of tolerability requires a review of all available data, including randomised controlled trials (RCTs), observational studies and postmarketing surveillance studies. Assessing the relative tolerability of atypical antipsychotics is hampered by the paucity of RCTs that compare these drugs head-to-head, and limited and inconsistent reporting of adverse effect data that makes cross-study comparisons difficult. Despite methodological problems in assessment and interpretation of tolerability data, important differences exist between the atypical antipsychotics in the relative risk of acute extrapyramidal symptoms (highest risk: higher doses of risperidone), hyperglycaemia and dyslipidaemia (highest risk: clozapine and olanzapine), hyperprolactinaemia (highest risk: amisulpride and risperidone), prolongation of heart rate-corrected QT interval (QTc) [highest risk: ziprasidone and sertindole] and weight gain (highest risk: clozapine and olanzapine). Sedation, antimuscarinic symptoms, postural hypotension, agranulocytosis and seizures are more common with clozapine than with other atypical antipsychotics. The variation in their tolerability suggests that it is misleading to regard the atypical antipsychotics as a uniform drug class, and also means that the term 'atypical antipsychotic' has only limited usefulness. Differences between the atypical agents in terms of efficacy and pharmacodynamic profiles also support this view. As tolerability differs between specific conventional and atypical drugs, we conclude that broad statements comparing the relative risk of specific adverse effects between 'atypical' and 'conventional' antipsychotics are largely meaningless; rather, comparisons should be made between specific atypical and specific conventional drugs. Adverse effects are usually dose dependent and can be influenced by patient characteristics, including age and gender. These confounding factors should be considered in clinical practice and in the interpretation of research data. Selection of an antipsychotic should be on an individual patient basis. Patients should be involved in prescribing decisions and this should involve discussion about adverse effects.

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.

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.

Correction par le lithium des neutropénies induites par la clozapine (deux cas)

Despite the availability of new treatments, the antipsychotic effectiveness of clozapine has not been matched yet. Unfortunately, its regulation is limited by the side effects. The most detrimental is the hematologic toxicity (neutropenia and agranulocytosis) which requires a regular biological monitoring. Treatment with clozapine must be stopped in those cases of secondary granulocytopenia for about 3% of the patients. The current psychiatric drug lithium carbonate has an opposite effect: it can induce leukocytosis. Thus, lithium carbonate is administered in leukopenia, as well as in many hematologic and immunological diseases. However, few teams have used lithium in order to alleviate clozapine-induced granulocytopenia. We report here 2 patients who developed severe neutropenia (neutrophil count<1.5 yen 10 (9)/L) and for whom the use of lithium enabled us to continue the treatment by clozapine. The first patient had a granulocyte rate constitutionally low which rapidly decreased with clozapine. Thanks to the administration of lithium, he recovered quickly a normal blood cell count, which in fact was much higher than his normal rate. According to our research, it's the first time that lithium is reported to be so efficacious in a patient with such a low rate of granulocytes before treatment. It may be that clozapine is not used for those kinds of patients. The second patient developed granulocytopenia after one year of treatment with clozapine. The use of lithium increased so much the number of granulocytes that we continued the treatment with clozapine alone. After 4 months, there is no reappearance of granulocytopenia. We must take into account the partial and contradictory reports in the literature. However, if this result is confirmed, it could be of a high interest to extend the prescription of clozapine, the most effective current antipsychotic drug.

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.

Clozapine-induced neutropenia in children: management with lithium carbonate

Clozapine, an atypical antipsychotic, is the most effective medication for treatment-resistant schizophrenia, but its use is limited by the high risk of neutropenia and agranulocytosis. In children, the rate of clozapine-induced neutropenia is even higher than in adults. We report two cases of children 7- and 12-years old diagnosed with very early onset schizophrenia, who developed neutropenia when treated with clozapine. In both cases addition of lithium carbonate elevated the white blood count (WBC) allowing clozapine rechallenge. WBC and total neutrophil count remained stable long-term with coadministration of clozapine (400-425 mg per day) and lithium with the blood level of 0.8-1.1 microg/mL. This report supports the use of adjunct lithium for clozapine-induced neutropenia as a safe and successful strategy in children.