Clozapine: an appraisal of its pharmacoeconomic benefits in the treatment of schizophrenia

Clozapine and cardiotoxicity - A guide for psychiatrists written by cardiologists

This review discusses the rare but potentially life-threatening cardiovascular side-effects of myocarditis and dilated cardiomyopathy associated with the use of Clozapine. The clinical presentation of these conditions is non-specific, making it difficult to both risk-stratify and identify patients who develop these consequences. This review aims to examine the proposed aetiologies, diagnostic approaches and subsequent management strategies of cardiotoxicity associated with clozapine use; offering guidance to psychiatrists and general physicians. Current evidence highlights the importance of accurate diagnosis to prevent premature and unnecessary cessation of clozapine. Guidance on monitoring and reintroduction of the drug is emerging and current practice recommends a combination of regular monitoring of biomarkers and imaging to make a diagnosis of cardiotoxicity although further work is needed to establish evidence-based guidelines.

Impacts of Electroconvulsive Therapy on 1-Year Outcomes in Patients With Schizophrenia: A Controlled, Population-Based Mirror-Image Study

OBJECTIVES

Despite the decline in the use of electroconvulsive therapy (ECT) in patients with schizophrenia, ECT augmentation is still recommended for those with poor response to standard pharmacological intervention. However, the effectiveness of augmentation of antipsychotics with ECT on long-term clinical outcomes needs to be verified in an expanded sample.

METHODS

Patients who were hospitalized for schizophrenia and received ECT for the first time during that hospitalization were identified from the total population health insurance database in Taiwan between 2002 and 2011. A comparison group was randomly selected and matched by age, gender, calendar year of hospitalization, and duration of hospitalization. Using a mirror-image design, the changes in rates of psychiatric and overall hospitalization, length of hospital stay, number of emergency department visits, and direct medical costs across the 1-year pre- and post-treatment periods were examined.

RESULTS

A total of 2074 patients with the same number of comparison participants were included in the analysis. The rate of re-hospitalization decreased significantly in the ECT group during the 1-year post-treatment period, while there was no significant difference in the comparison group. Correspondingly, the total medical expenses increased significantly in the non-ECT group, but not in the ECT group. Notably, the reduction in the psychiatric re-hospitalization rate in the ECT group was more pronounced among those treated with clozapine or a medium-high average daily dose of antipsychotics.

CONCLUSION

This 1-year mirror-image analysis indicated that augmentation of antipsychotics with ECT in schizophrenic patients was associated with a reduced rate of psychiatric re-hospitalization.

Clozapine use reduced psychiatric hospitalization and emergency room visits in patients with bipolar disorder independent of improved treatment regularity in a three-year follow-up period

OBJECTIVES

The efficacy of clozapine in bipolar disorder remains to be systemically examined. In the current study, we sought to disentangle the effect of clozapine from that of improved treatment regularity and to compare the effect of clozapine with the effect of regular treatment for bipolar disorder by exploring the complete 10-year clozapine prescription data from a Taiwanese total population health claims database.

METHODS

In the period between 2000 and 2009, 3,874 (3.3%) out of the 117,785 patients identified as having bipolar disorder in a Taiwanese total population health claims database were ever prescribed clozapine. Among them, 920 patients with bipolar disorder who had good pre-clozapine medication compliance and received at least two clozapine prescriptions were further categorized according to their clozapine medication possession ratio (MPR) as regular users (MPR ≥ 0.8; n = 476) and irregular users (MPR < 0.8; n = 444). Using a mirror-image design, we compared the numbers of emergency room (ER) visits, hospitalizations and hospital days, and the average durations of a single hospitalization during the pre- and post-clozapine mirror periods with a follow-up time of up to three years, controlling for time-variant course confounders.

RESULTS

The patterns of change in outcome indices from the pre-clozapine period to the post-clozapine period differed significantly between the two clozapine-user groups. Clinical outcome indices improved only in regular users, while they deteriorated in irregular users. Over the three-year follow-up period, the irregular users consistently had a higher adjusted risk for increased numbers of ER visits [odds ratio (OR): 2.06-2.43], hospitalizations (OR: 2.52-3.22), and total hospital days (OR: 2.42-2.91) when compared to the regular users. Thus, effects of clozapine were consistently demonstrated in one- to three-year mirror comparison periods.

CONCLUSIONS

Clozapine, when used with high treatment regularity (MPR > 0.8), was effective in reducing the numbers of ER visits, hospitalizations, and total hospital days in patients with bipolar disorder with previous frequent hospitalizations and ER visits despite regular pre-clozapine treatment for bipolar disorder. However, high early attrition and suboptimal treatment compliance need to be rectified in order to optimize the outcome of clozapine treatment in bipolar disorders.

Clozapine maintenance therapy in schizophrenia

Long-term pharmacotherapy with antipsychotic agents is an important aspect of the management of schizophrenia. In patients responsive to the chosen treatment, maintenance therapy is usually conducted by halving the drug dose that has proven effective during the acute phase. This strategy is suitable for maintaining remission; moreover, it can improve the patients' quality of life. Records from over 1000 patients treated with clozapine during the past 22 years were examined; 782 of these patients were diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision (DSM-IV-TR) criteria (with the modification in early years). From this group, 181 patients were treated with clozapine for at least a year. The mean duration of long-term maintenance treatment with clozapine was 12.2+/-4.25 years (range: from 14.5 months to 18 years). Clozapine was administered in a daily dose of 50-200 mg (mean: 71.5+/-14.12 mg). In 76 schizophrenics, treatment was initiated with clozapine, whereas 105 patients were switched over from other treatments after their failure. The control group comprised 152 patients on long-term maintenance therapy with haloperidol. Clozapine administered for long-term maintenance therapy was effective both in paranoid and in catatonic schizophrenia. It also accomplished good results in patients with disorganized or residual schizophrenia, as well as in individuals with schizoaffective psychosis. Relapse rate was similar to that observed in the haloperidol group; however, patient compliance, side-effect profile, and therapeutic efficacy were all superior in the clozapine group. Long-term maintenance therapy with clozapine is successful. Compliance is good; schizophrenic patients are willing to take this atypical antipsychotic for years on end. Clozapine treatment is associated with a low relapse rate and a favorable safety profile.

Clozapine: in prevention of suicide in patients with schizophrenia or schizoaffective disorder

The atypical antipsychotic agent clozapine is associated with a lower propensity for extrapyramidal symptoms than classical antipsychotic agents. The pharmacokinetics of clozapine are affected by wide interpatient variability and a potential for drug interactions. Some studies have shown a relationship between plasma concentrations, duration of treatment and antipsychotic clinical response. Clozapine (mean 274.2 mg/day; n = 490) had a greater preventive effect on suicidality among patients with schizophrenia or schizoaffective disorder at high risk for suicide than olanzapine (mean 16.6 mg/day; n = 490) in a randomised, rater-blinded, multicentre study (p < 0.05; a 22-24% improvement). Other prospective noncomparative trials of the effects of clozapine on suicidal ideation or attempts endorsed these results, while results from retrospective trials are equivocal. Clozapine is commonly associated with sedation, hypersalivation, tachycardia, dizziness, constipation and orthostatic hypotension. Agranulocytosis, diabetes mellitus and weight gain may also occur.

The cost-effectiveness of clozapine: a controlled, population-based, mirror-image study

A retrospective cohort study, with a mirror-image design, was used to measure inpatient service utilization in 63 consecutive patients started on clozapine from a geographical catchment area compared to a control group matched for previous inpatient service use. An intent-to-treat analysis, including those patients (n = 28) who discontinued clozapine during the study period, showed a significant reduction in number of admissions and total time spent in hospital in the 2 years following clozapine initiation compared to the previous 2 years and to the follow-up period in the control group. This translated into a reduction of 7,300 pounds in hospitalization costs per patient started on clozapine, over the 2-year period. In those patients who continued clozapine treatment for the whole of the 2-year period, there was a two-thirds reduction in number of admissions and total time spent in hospital compared to no change in the clozapine discontinuers. These findings suggest that clozapine is a clinically and cost-effective intervention for severe schizophrenia in routine clinical settings.

The economic value of atypical antipsychotics: A comparison of risperidone and olanzapine revisited

Careful analysis of clinical experience to date throws fresh light on the optimal and actual doses used in clinical practice of risperidone and olanzapine. Since launch, the optimal dose for treatment of schizophrenia of risperidone has been established at 4-6 mg/day and that of olanzapine at around 15 mg/day. We have applied these more realistic dosing assumptions to the published economic comparisons between the various atypical agents and conclude that there are economic and efficacy arguments for risperidone to be considered as the first choice for treatment of patients with schizophrenia. The other atypicals, such as olanzapine and clozapine, should be used as second-line therapy in preference to conventional agents such as haloperidol. Funding arguments support this approach and reinforce the need to reconsider therapy for patients whose current treatment may not be optimal.

New strategies for old problems: tardive dyskinesia (TD). Review and report on severe TD cases treated with clozapine, with 12, 8 and 5 years of video follow-up

Tardive dyskinesia (TD) is the most feared and troublesome extrapyramidal side-effect of prolonged neuroleptic (NL) treatment. We present a review of TD. Its pathophysiology remains elusive, although extrapyramidal symptoms (EPS) increase the liability for TD. Nowadays, therefore, avoidance of all EPS remains the best preventive strategy, as it is not possible to predict which liable patients will develop TD, or of what type or severity. TD frequently includes dystonic features, and is more disabling when these dystonias are present. Clozapine (CLZ) has been reported to be effective in suppressing nearly 60% of TD syndromes, specially those with dystonic features. Based on the few reports in the literature on CLZ and TD by the early 1980s, we started to videotape the first severe TD patient treated with CLZ in 1984. We present the first three case reports of severe TD, with prominent disabling dystonic features, treated with CLZ and videotaped since pretreatment and then periodically for 12, 8 and 5 years of follow-up, respectively. The patients' current diagnosis, gender and age are: Case 1, DSM-IV Schizophrenia Residual Type, male, 39 years; Case 2, DSM-IV Polysubstance Related Disorder, Borderline Personality Disorder, female, 28 years; Case 3, DSM-IV Schizoaffective Disorder, male, 40 years. Two of them presented with a recurrence of TD because of CLZ interruption within the first 2 months of treatment, with no further breakthrough to date. The first two cases have complete remission of TD; the third case is still improving after 5 years of CLZ treatment, with only minor dystonic features persisting that constitute no impairment for work or daily routines at present. All patients, independent of their psychiatric primary diagnosis, have shown significant and progressive improvement in both motor and psychosocial aspects. None of them has been rehospitalized. Long-term treatment and follow-up is required to avoid TD recurrence and to assure full assessment of treatment effectiveness. Ideally, periodic video recording with standardized examination is advisable for long-term follow-up and outcome assessment. At present, CLZ could be regarded as the drug of choice for patients with TD, specially for those with disabling and or dystonic features and who require ongoing NL therapy. The use of novel antipsychotic agents for TD treatment and prevention, with their low EPS liability, is promising, but has yet to be tested.

Modeling the lifetime costs of treating schizophrenia in Australia

Schizophrenia is arguably one of the most costly mental illnesses in terms of its impact on the economy, on the health system, and on patients and their families. This paper provides a framework for analyzing schizophrenia; this framework, in a limited data environment, generates estimates of the costs and outcomes of this disease based on location of treatment. This model differs from previous cost-of-illness studies in that it uses a Markov framework to estimate the incidence costs associated with schizophrenia based on a projected amount of a patient's lifetime spent in these treatment locations. The author believes this is the first time such a model has been developed and applied to estimating not only the community costs of schizophrenia but also the cost implications of treatment options and policy choices in Australia. Using a fundamental matrix solution, lifetime costs of illness are calculated and the principal cost drivers in schizophrenia treatment are identified.

Economic and health state utility determinations for schizophrenic patients treated with risperidone or haloperidol

The current study uses utility analysis to assess economic and quality-of-life benefits of risperidone in patients with chronic schizophrenia. A retrospective analysis was performed on Positive and Negative Syndrome Symptoms (PANSS) data obtained from the published Canadian multicenter risperidone trial (part of the North American trial). Cluster analysis applied to endpoint PANSS scores, including all patients (N = 135), identified three clusters representing 130 patients with mild, moderate, and severe symptomatology. A narrative health state profile was written for each cluster, and 100 psychiatric nurses from Washington, DC, were asked to assign preference ratings to each one using linear analog and standard gamble (SG) methods. Mean utility values (confidence interval 95%) obtained from the SG ratings for the three health state profiles were 0.61 +/- 0.069 (mild); 0.36 +/- 0.073 (moderate); and 0.29 +/- 0.071 (severe). The mild health state (including the majority of risperidone 6 mg-treated patients) was rated by nurses to have a 0.25 +/- 0.0501 greater utility than the moderate health state (composed of the majority of haloperidol-treated patients). The results of these utility evaluations (SG) by the nurses were related to the clinical outcome for three of the six drug treatment groups (N = 65) by multiplying the percentage of patients in each of the three clusters, both at baseline and end-point, who were receiving risperidone 6 mg/day, haloperidol, or placebo, by the utility value for the health state assigned to that cluster. The gain in utility for risperidone-treated patients was 2.6 times higher (0.125) compared with haloperidol-treated patients (0.049), and 7 times higher compared with placebo (-0.021). After multiplying the gain in utility of each treatment by the remaining expected life span for men and women, it was found that risperidone-treated patients obtained more than twice as many quality-adjusted years as haloperidol patients. The incremental drug treatment cost divided by the incremental benefit of risperidone versus haloperidol was found to yield a favorable, generally accepted cost-utility ratio.

Management of treatment resistant schizophrenia unresponsive to clozapine

A recent challenge in schizophrenia has been the management of patients who have failed to respond not only to standard therapeutic regimes but also to trials of atypical neuroleptics such as clozapine and risperidone. This article focuses on the further psychological and pharmacological management of such patients.