Olanzapine-induced neutropenia: mechanism and treatment

Haematological adverse effects associated with olanzapine in adolescents with anorexia nervosa: Three case reports

OBJECTIVES

To describe haematological adverse effects in adolescents with anorexia nervosa who are taking olanzapine.

METHODS

Case series report.

CASE REPORT

The reported cases (two female patients and one male) were found to have blood test abnormalities after starting olanzapine and to rapidly recover their platelet and neutrophil values after the drug was discontinued. Low haemoglobin values persisted longer than observed in other series. These abnormalities became more noticeable when the dose of olanzapine was increased to 5 mg/day (initial dose 2.5 mg/day). It should be noted that two of the patients already had values indicative of mild neutropenia before they started the antipsychotic drug, and that these worsened as they continued taking the drug. In one of the patients there was only a decrease in neutrophil values, as well as mild anaemia.

CONCLUSIONS

This first case series of haematological abnormalities in adolescents with anorexia nervosa who are taking olanzapine found values corresponding to pancytopenia in two of the three cases reported. It would be worthwhile to consider heightening haematological surveillance in this population when starting treatment with olanzapine and rethinking our knowledge regarding the frequency of these side effects.

Olanzapine-Induced Neutropenia

Olanzapine-induced neutropenia is a rare adverse effect that is currently poorly described in literature. Although neutropenia is a known adverse effect of clozapine, it has been associated with the use of other antipsychotic medications like olanzapine. This case report describes and reviews a case of olanzapine-induced neutropenia in a schizophrenic patient. Although the mechanism of antipsychotic-induced neutropenia is still debated, this report attempts to discuss current theories as well as supply evidence in literature of this rare but potentially dangerous adverse effect.

Quetiapine XR-induced neutropenia: is a clozapine trial still possible for treatment-resistant schizophrenia? A case report

AIM

Our case report addresses the use of clozapine in patients who have a history of quetiapine XR-induced neutropenia. There are no current guidelines for this situation.

METHODS

We present the case of a young woman treated with clozapine at a first-episode psychosis clinic after a moderate quetiapine XR-induced neutropenia (0,5-1,0 × 10(9)  L(-1) ).

RESULTS

The patient was successfully treated with clozapine and lithium, with less psychotic symptoms and a better level of functioning. The neutrophil count remained normal during the treatment period, which has been longer than a year.

CONCLUSION

The outcome of this case supports the notion that clinicians could consider introducing clozapine in treatment-refractory patients who have a history of quetiapine XR-induced neutropenia, with close blood monitoring. Lithium co-administration may play a role in maintaining a normal neutrophil count.

A case with neutropenia related with the use of various atypical antipsychotics

Herein, we report here a case of a 21-year-old patient with a conduct disorder, who had neutropenia associated with treatment with 4 different antipsychotics (olanzapine, quetiapine, risperidone, and aripiprazole) on a sequential basis. This case supports the hypothesis that patients who developed antipsychotic-induced neutropenia on one medication are more likely to develop neutropenia when taking other antipsychotics. Based on this finding, we may suggest that the number of white blood cell and neutrophil counts in patients with a history of antipsychotic-induced neutropenia needs to be carefully monitored during antipsychotic treatment.

Does switching to another antipsychotic in patients with clozapine-associated granulocytopenia solve the problem? Case series of 18 patients

Clozapine is a well-known drug that is used in treatment-resistant schizophrenia, but granulocytopenia, which may lead to a potentially fatal condition such as agranulocytosis, limit its use. The question about which antipsychotic should be used after a diagnosis of clozapine-associated granulocytopenia is difficult to answer, because antipsychotics other than clozapine may also have hematologic toxicity, or they may prolong clozapine-associated granulocytopenia. In this study, we aimed to find out the incidence of clozapine-associated granulocytopenia in our treatment sample and discuss suitable antipsychotic drug options in terms of hematologic toxicity, for management of clozapine-associated granulocytopenia.

SUBJECTS

One thousand five hundred twenty-four schizophrenia patients, treated with clozapine, were included in the study.

METHODS

Patients' white blood cell counts were monitored closely. Should granulocytopenia related to clozapine be diagnosed, clozapine was stopped immediately, and a new antipsychotic that the patient did not have a history of use was begun, according to the clinical profile of the patient. Persistent low white blood cell count after the 10th day of cessation of clozapine was accepted as prolongation effect.

RESULTS

Of the 1524 schizophrenia patients, 18 were diagnosed to have granulocytopenia, which means that 1.18% of the clozapine users developed granulocytopenia related to clozapine. Six of the patients were treated with olanzapine, 5 patients were treated with quetiapine, 1 patient was treated with risperidone, and 6 patients were treated with amisulpride after clozapine is stopped. None of the patients treated with risperidone or amisulpride showed prolonged low white blood cell count. Two of the patients treated with olanzapine (33.3%) and 2 of the patients treated with quetiapine (40.0%) showed prolonged leukopenia.

DISCUSSION

It is noteworthy that 33.3% of the patients treated with olanzapine and 40.0% of the patients treated with quetiapine showed prolonged leukopenia. This finding is also consistent with the literature that declares higher numbers of cases about prolongation of clozapine-associated granulocytopenia for olanzapine and quetiapine than risperidone and amisulpride. After switching to another antipsychotic drug, close monitoring of white blood cell count on a daily basis for the first 2 weeks should be continued until white blood cell counts are stabilized. Quetiapine and olanzapine especially need attention after clozapine-associated granulocytopenia. Further studies with larger series and longer follow-up should be carried out.

Antipsychotic Drug Treatment for Patients with Schizophrenia: Theoretical Background, Clinical Considerations and Patient Preferences

The cornerstone in treatment of psychosis is antipsychotic drugs. Treatment options have increased over the years; newer antipsychotic drugs with a proposed increased efficacy regarding negative and cognitive symptoms, but also a shift in side-effects from neurological side-effects to metabolic side-effects have arisen as the new challenge. The basis of successful pharmacological treatment is a fundamental understanding of the mechanisms of action, the desired effects and side-effects of antipsychotic drugs, a good relationship with the patient and a thorough monitoring of the patient before and during treatment. The clinically relevant aspects of antipsychotic drug treatment are reviewed; mechanism of antipsychotic drug action, clinical considerations in treatment, switching antipsychotic drugs, polypharmacy, safety and patient preference.

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.

Fatal agranulocytosis: the use of olanzapine in a patient with schizophrenia and myelodysplasia

Neutropenia and agranulocytosis are risks known to occur with phenothiazines and clozapine. The mechanisms responsible for these conditions currently remain unclear. To our knowledge, no case of fatal agranulocytosis as a result of olanzapine treatment was reported in the literature. Thus any case of severe neutropenia occurring in a patient receiving olanzapine is alarming to clinicians. First, a review of the literature produced 41 anecdotic cases of neutropenia or agranulocytosis during treatment with olanzapine (Zyprexa) reported in a total of 24 publications. Second, we report a case of neutropenia, which proved to be fatal in a schizophrenia patient receiving olanzapine and thiazide. The cause of the death was Myelodysplastic syndrome. There is not enough evidence to prove the involvement of either olanzapine or hydrochlorothiazide or the interaction between them in this patient's myelodysplasia. Bone marrow cytogenetic study confirmed the deletion of the long arm of chromosome 11, as reported in myeloid leukemia. If this patient would have died suddenly without the laboratory investigations that lead to the diagnosis of myeloblastic leukemia, the cause would have been probably and wrongfully allotted to treatment with olanzapine.

Prolongation of clozapine-induced leukopenia with olanzapine treatment

Clozapine is a well-known antipsychotic to cause fatal agranulocytosis but there are only a few case reports about the risk of leukopenia and agranulocytosis associated with other atypical antipsychotics. Olanzapine has structural pharmacological similarities to those of clozapine and reports about haematological adverse effects of olanzapine include three groups: the first group includes cases of olanzapine-induced neutropenia, the second informing that olanzapine is safe after clozapine induced agranulocytosis and the third group forms prolongation of clozapine-induced leukopenia with olanzapine use. The aim of this paper is to report a case of prolongation of clozapine-induced leukopenia despite olanzapine treatment and discuss leukopenia caused by atypical antipsychotic use in the light of recent and limited literature.

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.

Clozapine induces oxidative stress and proapoptotic gene expression in neutrophils of schizophrenic patients

The present study examined cellular effects of the atypical antipsychotic drug clozapine on blood cells of treated patients with and without clozapine-induced agranulocytosis (CA). Blood from one patient who commenced clozapine treatment was examined at weekly intervals for 128 days. Olanzapine-treated (n = 5) and polymedicated (n = 14) schizophrenic patients, as well as healthy subjects (n = 19) and septic shock patients (n = 8), were studied for comparison. We observed dramatically increased numbers of native neutrophils stained for superoxide anion production (P < or = 0.005, n = 10) and significantly elevated expression levels of the proapoptotic genes p53 (P < or = 0.020), bax alpha (P < or = 0.001), and bik (P < or = 0.002) in all tested non-CA patients (n = 19) and CA patients (n = 4). In non-CA patients, the expression of these genes did not correlate to the percentage of apoptotic neutrophils (2.0% +/- 1.3%), but in CA patients about 37% of the neutrophils show morphologic signs of apoptosis (P < or = 0.001). Under G-CSF therapy of CA, the number of apoptotic neutrophils and the expression of the proapoptotic genes decreased significantly. In conclusion, high production of reactive oxygen species in neutrophils of clozapine-treated patients, together with increased expression of proapoptotic genes, suggests that neutrophils are predisposed to apoptosis in schizophrenic patients under clozapine therapy. The correlation between drug and proapoptotic markers was highest for clozapine and bax alpha as well as superoxide anion radicals. This indicates oxidative mitochondrial stress in neutrophils of clozapine-treated patients which probably contributes to the induction of apoptosis and sudden loss of neutrophils and their precursors in CA patients.

Toxicology and overdose of atypical antipsychotic medications in children: does newer necessarily mean safer?

PURPOSE OF REVIEW

Atypical antipsychotic medications (second-generation antipsychotics) have been increasingly used in the treatment of a number of psychotic disorders since their introduction in 1988, with the newest medication introduced in 2002. Justification for their use includes claims of equal or improved antipsychotic activity over first-generation antipsychotics, increased tolerability, and decreased side effects. However, there are still significant adverse effects and toxicities with this class of medications. Toxicologic exposures and fatalities associated with atypical antipsychotics continue to increase in the United States, with 32,422 exposures and 72 deaths in 2003. There have also been Food and Drug Administration warnings in the past year about how some atypical antipsychotics have been marketed to minimize the potentially fatal risks and claiming superior safety to other atypical antipsychotics without adequate substantiation, indicating the toxicologic potential of these agents may be underestimated.

RECENT FINDINGS

Continued research to evaluate adverse effects and tolerability of atypical antipsychotics compared with first-generation antipsychotics and each other is reviewed. This article also reviews the pharmacodynamics, pharmacokinetics, and drug interactions with these medications. New therapeutic monitoring recommendations for this class of medications have also been proposed. Finally, clinical toxicity in overdose and management are reviewed.

SUMMARY

While new atypical antipsychotic medications may have a safer therapeutic and overdose profile than first-generation antipsychotic medications, many adverse and toxic effects still need to be considered in therapeutic monitoring and overdose management.