Clozapine: current status and role in the pharmacotherapy of schizophrenia

Safety of BEN guidelines in clozapine treatment: A Canadian perspective

OBJECTIVE

Unidentified benign ethnic neutropenia (BEN) has been recognized as a factor contributing to clozapine underutilization and discontinuation. Guidelines were implemented to accommodate BEN in Canada, and our main objective was to evaluate clozapine's safety in a sample of Canadian psychiatric patients with BEN.

METHOD

A retrospective chart review was conducted at the Centre for Addiction and Mental Health, Toronto, Canada. Through the clozapine clinic registry, participants were identified who (i) received clozapine using the approved BEN guidelines for hematological monitoring, and (ii) had at least one complete blood count pre- and post-clozapine initiation.

RESULTS

Our sample population was comprised of 41 BEN patients who were African-Caribbean (49 %), African (34 %), African-North American (12 %), Middle Eastern (2 %), and Indian-Caribbean (2 %). There was a significant reduction in hematological alerts for these patients while monitored under BEN guidelines (p < 0.001). The mean within-patient ANC value was not significantly different one year after clozapine initiation compared to the pre-clozapine baseline (p = 0.069). None of the patients discontinued clozapine for hematological reasons.

CONCLUSIONS

Findings demonstrated that patients monitored under the modified hematological guidelines for BEN can be safely treated with clozapine. These findings have important clinical ramifications as increased implementation of BEN guidelines may allow for broader use of clozapine.

Positive symptoms are associated with clinicians' global impression in treatment-resistant schizophrenia

Previous investigations on the relationship between global rating measures and symptoms have not considered the additional role of functioning. In this naturalistic study, we examined the relationship between symptom domains and functioning on Clinical Global Impression scales for severity (CGI-S) and improvement (CGI-I) in a sample of patients with schizophrenia assessed to be treatment resistant. Participants were patients with a diagnosis of schizophrenia or schizoaffective disorder who failed 2 prior antipsychotic trials and were considered candidates for clozapine. They were assessed on the 18-item Brief Psychiatric rating Scale (BPRS), Social Occupational Functioning Assessment Scale (SOFAS), and CGI-S at baseline. A subset of patients was followed up at 6 weeks after initiation of clozapine and assessed on the CGI-I. The independent effects of symptom domains and functioning on the CGI scales were examined via multivariate regression models. Brief Psychiatric rating Scale positive factor (P < 0.001) and SOFAS (P < 0.001) scores were significant determinants of CGI-S at baseline. Multivariate models suggested that relative change measures had a better fit for the CGI-I compared to absolute change measures (R = 0.72 vs R = 0.61, respectively). Improvements in BPRS positive (P < 0.001) and affect (P = 0.002) factors and SOFAS (P = 0.030) scores were significant determinants of CGI-I. Ratings of 1 and 2 on the CGI-I corresponded to a mean relative change in the BPRS total of 65% and 41%, respectively. Positive symptoms were a key determinant of clinicians' impression of severity and improvement in this study. Although psychosocial functioning played a large part in determining severity, it was not as significant in the assessment of improvement.

Treatment-refractory schizophrenia

Between one-third and one-half of the individuals who meet diagnostic criteria for schizophrenia remain actively ill despite optimal pharmacological treatment. These individuals tend to progressively deteriorate in terms of social and vocational functioning despite major public and private investments in their rehabilitation. For patients who do not respond to the first prescribed antipsychotic drug, current clinical practice is to switch to a second and a third drug, and eventually to clozapine, the only antipsychotic drug proven to be effective in treatment-refractory schizophrenia (TRS). Occasionally, two antipsychotics are given concomitantly or psychotropic drugs are added to antipsychotic drugs; however, very few empirical data exist to support this practice. Although there are many exceptions, patients who do not benefit from the first prescribed drug will not benefit from any pharmacological intervention. Therefore, efforts are under way to determine the reason for lack of response to available treatments and devise novel, more effective treatments. To be successful these efforts must result in a more specific definition of TRS, as well as in a better understanding of the illness pathophysiology and the mechanism of action of the drugs.

Management of treatment resistance in schizophrenia

A systematic approach to the evaluation and characterization of treatment resistance in schizophrenia has become increasingly important since the introduction of the second-generation antipsychotics. The need for accurate evaluation will increase further as other new antipsychotic medications are developed. Patients with schizophrenia may manifest poor response to therapy because of intolerance to medication, poor adherence, inappropriate dosing, as well as true resistance of their illness to antipsychotic drug therapy. Criteria for treatment-resistance are presented to help in standardizing treatment and clinical trials. As clinicians face the decision of when to change or augment antipsychotic medications, a clear understanding of the appropriate length of a treatment trial and which target symptoms respond to antipsychotic therapy is critical for maximizing response in patients with treatment-resistant schizophrenia.

Treatment of the special patient with schizophrenia

Special patient populations with schizophrenia have received little attention. These populations include adolescents, the elderly, substance abusers, and patients who are considered treatment-resistant. Interest in these populations is rapidly growing, especially with regard to their treatment with second-generation antipsychotics. This article describes the treatment of special patient populations and summarizes the research that has been done in this field.

Olanzapine for patients with treatment-resistant schizophrenia: a naturalistic case-series outcome study

OBJECTIVE

This prospective, consecutive case-series outcome investigation evaluates the effectiveness of olanzapine in 16 patients with treatment-resistant schizophrenia.

METHOD

Treatment resistance was defined as nonresponsiveness to at least 3 antipsychotic drugs from at least 2 different chemical classes. A minimum baseline score on the Brief Psychiatric Rating Scale (BPRS) of 45 was required for enrolment. Outcome evaluation measures included the BPRS, Global Assessment Scale (GAS), and Abnormal Involuntary Movement Scale (AIMS).

RESULTS

Subjects (n = 16) has a mean age of 40 years and mean duration of illness of 16 years. Olanzapine treatment was initiated at 5 mg daily and was increased based on clinical judgement up to a maximum of 40 mg daily. Significant decreases in mean BPRS (P < 0.001) and GAS (P < 0.01) scores were observed at weeks 4, 8, 12, and 16, compared with baseline. Eight of 16 patients responded to olanzapine, as defined by a 20% decrease in BPRS score by week 16. Dyskinetic movements significantly increased at week 4 (P < 0.01) but did not differ from baseline at weeks 8 and 16.

CONCLUSION

These results suggest that olanzapine at moderate to high doses may offer an effective treatment for a significant proportion of patients with schizophrenia nonresponsive to multiple trials of conventional antipsychotics. A randomized controlled trial is encouraged to validate these findings, and comparative trials are required to determine when clinicians should consider this approach.

Olanzapine versus haloperidol in the treatment of schizoaffective disorder. Acute and long-term therapy

BACKGROUND

The effectiveness of antipsychotic monotherapy in schizoaffective disorder is limited, and further constrained by safety concerns.

AIMS

We aimed to compare the efficacy, tolerability and safety profile of the new pharmaceutical, olanzapine, with haloperidol.

METHOD

Data were assessed from 300 DSM-III-R schizoaffective subjects from a larger double-blind prospective international study. Subjects were randomly allocated to six weeks of olanzapine (5-20 mg) or haloperidol (5-20 mg) treatment; responders were followed for up to one year of double-blind, long-term maintenance therapy.

RESULTS

Olanzapine-treated patients achieved a statistically significant greater improvement than haloperidol treated patients on overall measures of efficacy, including clinical response. Significantly fewer olanzapine patients left the study early, and fewer adverse events were observed among those receiving olanzapine. During maintenance, olanzapine-treated patients continued to experience additional improvement, with fewer EPS but more weight gain than those on haloperidol.

CONCLUSIONS

Olanzapine demonstrated substantial advantages over the conventional antipsychotic haloperidol in the management of schizoaffective disorder.

Hospital days in clozapine-treated patients

OBJECTIVE

To examine inpatient hospital days used by a group of patients with treatment-resistant schizophrenia for 3 years before and 3 years after clozapine initiation.

METHOD

A retrospective chart review of 26 consecutive admissions to an outpatient clozapine clinic was conducted for a 6-year period. The total number of hospital days was recorded.

RESULTS

Patients separated into 3 groups: those who used clozapine for 3 uninterrupted years (N = 11, 42.3%), those who interrupted but resumed clozapine and continued on to 3 years (N = 4, 15.4%), and those who abandoned clozapine treatment (N = 11, 42.3%). Only the group that was continuously on clozapine showed a decline in percentage of inpatient days during the 3-year follow-up period. Three of the 11 patients who discontinued clozapine died during the posttreatment period: 2 suicides and 1 "death by misadventure."

CONCLUSIONS

Continuous clozapine treatment significantly reduces days in hospital; this reduction was sustained throughout 3 years' follow-up. While the sample size is small, all patients were tracked over a 6-year period, and both drug continuers and dropouts were followed. The reduction in inpatient days may be lost if patients stop and then restart clozapine. For patients who do not respond to or abandon trials of clozapine, there is an urgent need to develop more effective treatment strategies.

Neuroleptic dosing in chronic schizophrenia: a 10-year follow-up

OBJECTIVE

To evaluate neuroleptic dosing patterns in individuals with schizophrenia over a 10-year interval.

METHOD

Changes in neuroleptic dosing between 1980 and 1990 were followed in 65 patients with a diagnosis of chronic schizophrenia.

RESULTS

According to more recent dosing guidelines, doses were already high at the time of initial evaluation, yet overall they continued to increase during the next decade of treatment for both males and females. Patients were almost equally divided, however, by those who underwent an increase (n = 33) and those whose dose remained stable (n = 4) or was decreased (n = 28).

CONCLUSION

A considerable number of patients with schizophrenia appear to receive progressively higher neuroleptic doses over the course of their illness, despite a lack of empirical data to support such an approach. Results are discussed in terms of current dosing recommendations and factors influencing dose changes.