Management of treatment resistant schizophrenia unresponsive to clozapine

What are patients' experiences of discontinuing clozapine and how does this impact their views on subsequent treatment?

BACKGROUND

Discontinuing what is considered the most effective treatment for treatment-resistant schizophrenia may precipitate feelings of failure or a relapse of illness. Clozapine treatment is discontinued for a variety of reasons, including non-adherence, intolerance, or lack of efficacy. Patients' experiences of discontinuing the "best" treatment and the impact on perceptions of subsequent antipsychotic treatment are important in developing an understanding of the factors affecting people's treatment choices. This study is the first of its type, seeking to explore people's perspectives on clozapine discontinuation.

METHOD

Semi-structured interviews with sixteen patients who had received clozapine and discontinued treatment-thirteen males and three females, age range: thirty-two to seventy-eight years old-were audio-recorded and transcribed. A modified inductive approach to analysis, based on grounded theory, was taken to identify commonalities and differences in patients' perceptions.

RESULTS

The three main themes identified from participants' experiences were: (1) positive and negative effects of treatment; (2) feelings of agency, being the capacity to make decisions about treatment and act independently; (3) choice of treatment in the future. Participants exhibited agency in making choices about medication, including risking relapse, while attempting self-management of medication effects. Different participants perceived the same side effect as beneficial or intolerable. Variation in subsequent treatment choices was reported, with some participants favouring depot (long-acting) injections. A participant was frightened when not told about clozapine's side effects, which led to the participant not being engaged in future treatment decisions. Others, despite suffering serious adverse effects, retained positive perceptions of clozapine; they experienced despair at finding an effective alternative.

CONCLUSIONS

Experiences with clozapine discontinuation evoked powerful emotions and resulted in clozapine being the benchmark for other treatments. Knowledge, agency, and being in control were important to participants in relation to treatment. Personal perceptions of treatments or beliefs about illness could lead to non-adherence. People value the clinician listening to their experiences to better understand their perspective, enabling concerns about medication to be addressed through true shared decision making.

TRIAL REGISTRATION

NHS Health Research Authority and Health and Care Research Wales, IRAS Project ID 225753, Research Ethics Committee (REC) reference: 18/NW/0413, 25/06/2018.

Clozapine resistant schizophrenia: Newer avenues of management

About 40%-70% of the patients with treatment-resistant schizophrenia have a poor response to adequate treatment with clozapine. The impact of clozapine-resistant schizophrenia (CRS) is even greater than that of treatment resistance in terms of severe and persistent symptoms, relapses and hospitalizations, poorer quality of life, and healthcare costs. Such serious consequences often compel clinicians to try different augmentation strategies to enhance the inadequate clozapine response in CRS. Unfortunately, a large body of evidence has shown that antipsychotics, antidepressants, mood stabilizers, electroconvulsive therapy, and cognitive-behavioural therapy are mostly ineffective in augmenting clozapine response. When beneficial effects of augmentation have been found, they are usually small and of doubtful clinical significance or based on low-quality evidence. Therefore, newer treatment approaches that go beyond the evidence are needed. The options proposed include developing a clinical consensus about the augmentation strategies that are most likely to be effective and using them sequentially in patients with CRS. Secondly, newer approaches such as augmentation with long-acting antipsychotic injections or multi-component psychosocial interventions could be considered. Lastly, perhaps the most effective way to deal with CRS would be to optimize clozapine treatment, which might prevent clozapine resistance from developing. Personalized dosing, adequate treatment durations, management of side effects and non-adherence, collaboration with patients and caregivers, and addressing clinician barriers to clozapine use are the principal ways of ensuring optimal clozapine treatment. At present, these three options could the best way to manage CRS until research provides more firm directions about the effective options for augmenting clozapine response.

Management of clozapine-resistant schizophrenia

The incidence of treatment resistance in schizophrenia (failure to respond to antipsychotic therapy) is about 20%. Factors that may contribute to it include non-adherence (non-compliance) to treatment, comorbid conditions and medication side-effects. The National Institute for Clinical Excellence recommends that clozapine be used for schizophrenia resistant to another atypical antipsychotic. Here we focus on patients who are also resistant to clozapine given in adequate dosage for sufficient duration. Switching from clozapine to a previously untried atypical (e.g. olanzapine, risperidone, quetiapine) might be of benefit in partial treatment resistance. In more difficult cases, augmentation of clozapine with benzamides (sulpiride, amisulpride) and anti-epileptics (lamotrigine) shows some success. In extreme treatment resistance, a strategy is recommended that combines the proven best drug for the particular patient and psychosocial treatments.

Commentary: the risks of enforcing clozapine therapy

Pereira et al's paper (1999, this issue) is to be welcomed in that it highlights an area of clinical decision that requires a careful balance of short- and long-term risks and benefits in the individual patient. In this (necessarily) brief commentary I will concentrate on this aspect, and leave aside any ethical and medico-legal considerations.

When all else fails

Aims and method

A small minority of treatment-refractory patients who could benefit from treatment with clozapine, refuse to comply with blood tests or oral treatment. Treatment with clozapine can be enforced under the Mental Health Act.

Results

An aide memoire was developed locally to guide clinicians through the process of enforcing clozapine treatment.

Clinical implications

It is possible to enforce treatment with clozapine under the Mental Health Act and so offer a valuable treatment option.

Treatment-Resistant Schizophrenia

Although treatment-resistant schizophrenia (TRS) was described 50 years ago and has a gold standard treatment with clozapine based on well-defined criteria, there is still a matter of great interest and controversy. In terms of the underlying mechanisms of the development of TRS, progress has been made for the elucidation of the neurochemical mechanisms. Structural neuroimaging studies have shown that patients with TRS have significant reduction of the prefrontal cortex volume when compared with non- TRS. This article updates and enhances our previous review with new evidence mainly derived from new studies, clinical trials, systematic reviews, and meta-analyses.

Missense mutation of the reticulon-4 receptor alters spatial memory and social interaction in mice

The reticulon-4 receptor, encoded by RTN4R, limits axonal sprouting and neural plasticity by inhibiting the outgrowth of neurites. Human association studies have implicated mutations in RTN4R in the development of schizophrenia, including the identification of several rare nonconservative missense mutations of RTN4R in schizophrenia patients. To investigate the effects of missense mutation of the reticulon-4 receptor on phenotypes relevant to schizophrenia, we behaviourally characterized a novel Rtn4r mutant mouse line with an amino acid substitution (R189H) in the Nogo-66 binding site. Behavioural assays included prepulse inhibition of acoustic startle, locomotor activity, social interaction and spatial cognition. When compared with wildtype littermates, Rtn4r mutant mice exhibited greater social preference, which may reflect a social-anxyolitic effect, and a mild impairment in spatial cognition. Given the mild effect of the R189H mutation of Rtn4r on behavioural phenotypes relevant to schizophrenia, our results do not support missense mutation of RTN4R as a strong risk factor in the pathogenesis of schizophrenia.

The role of neurexins in schizophrenia and autistic spectrum disorder

Schizophrenia and autistic spectrum disorder (ASD) are common, chronic mental conditions with both genetic and environmental components to their aetiology. The identification of genes influencing susceptibility to these disorders offers a rational route towards a clearer understanding of the neurobiology, and with this the prospect of treatment and prevention strategies tailored towards the remediation of the altered pathways. Copy number variants (CNVs) underlie many serious illnesses, including neurological and neurodevelopmental syndromes. Recent studies assessing copy number variation in ASD and schizophrenia have repeatedly observed heterozygous deletions eliminating exons of the neurexin-1α gene (but not the neurexin-1β gene) in patients with ASD and schizophrenia. The neurexins are synaptic adhesion proteins that are known to play a key role in synaptic formation and maintenance. The functional significance of the recurrent deletion is poorly understood, but the availability of mice with deletion of the promoter and first exon of neurexin-1α provides direct access to the biological effects of neurexin-1α disruption on phenotypes relevant to ASD and schizophrenia. We review the evidence for the role of neurexin-1α in schizophrenia and ASD, and consider how genetic disruption of neurexin-1α may underpin the neuropathology contributing to these distinct neurodevelopmental disorders.

Clinical aspects of super-refractory schizophrenia: a 6-month cohort observational study

OBJECTIVE

Approximately 30% of treatment-resistant schizophrenic patients do not fully respond to Clozapine and such patients are termed Clozapine non-responders or super-refractory schizophrenics. The aim of this study was to characterize patients with super-refractory schizophrenia according to demographic and psychopathological variables, as compared with patients with refractory schizophrenia or non-refractory subjects.

METHOD

One hundred two outpatients meeting DSM-IV criteria for schizophrenia were followed-up for 6 months. Subjects were classified into 3 groups: non-refractory (n=25), refractory (n=43) and super-refractory (n=34). Psychopathology was assessed by the Positive and Negative Syndrome Scale, the Schedule for Deficit Syndrome, the Calgary Depression Scale and the Quality of Life Scale. Patients were rated at 2-month intervals.

RESULTS

Higher levels of severity at the disease onset as well as higher severity of positive symptoms were found to be predictive of super-refractoriness.

CONCLUSIONS

The super-refractory schizophrenia patients have psychopathological predictive factors that need studies comparing brain images, genetical features and other clinical comparisons.

Subjective response and attitudes toward antipsychotic drug therapy during the initial treatment period: a prospective follow-up study in patients with schizophrenia

OBJECTIVE

In this prospective study, patients with schizophrenia were followed up for 3 months to investigate the impact of sociodemographic factors, psychopathology, change in psychopathology and side effects on subjective response and attitudes toward antipsychotics during the initial treatment period.

METHOD

We investigated 42 patients starting treatment with a new-generation antipsychotic. Next to the registration of demographic data various rating scales were used: the Positive and Negative Syndrome Scale (PANSS), the Udvalg for Kliniske Undersogelser (UKU) Side Effect Rating Scale and the Drug Attitude Inventory (DAI).

RESULTS

Two patients experienced a first episode of the illness and were neuroleptic naïve, and 40 had suffered from at least one prior episode of schizophrenia. Longer duration of illness as well as the amelioration of psychopathological symptoms had a positive impact on subjective response to treatment. Correlations between antipsychotic-induced side effects and drug attitude tended to be weak.

CONCLUSION

Our results emphasize the necessity of improving psychopathological symptoms during the initial treatment period to improve attitudes toward and compliance with treatment.

Treatment-resistant schizophrenia

This article opens with a brief history of pharmacologic treatment of schizophrenia. It then discusses the definition and treatment of treatment-resistant schizophrenia, with particular attention to clinical, biological and neuroimaging correlates, as well as the best treatment options, including the use of clozapine in patients who meet the definition of treatment-resistant schizophrenia.

Augmentation with a second antipsychotic in patients with schizophrenia who partially respond to clozapine: a meta-analysis

OBJECTIVES

To conduct a meta-analysis of randomized placebo-controlled trials (RCTs) of clozapine augmentation with another antipsychotic drug in patient with schizophrenia who partially respond to clozapine and compare the results with the findings of relevant open studies.

METHODS

A systematic literature search was conducted to identify eligible RCTs. All baseline, posttreatment, and change scores in these trials were included in the meta-analysis. For change in Brief Psychiatric Rating Scale/Positive and Negative Syndrome Scale total scores, the effect size was calculated, and for the proportion of patients with a reduction in Brief Psychiatric Rating Scale/Positive and Negative Syndrome Scale scores of 20% or more, the relative risk was calculated.

RESULTS

There was a total of 166 participants in the 4 eligible RCTs. Pooling effect sizes across these studies revealed clinically important heterogeneity (I = 63.5%). Analyzing by duration accounted for the heterogeneity (I = 0%), whereas analyzing by drug did not (I = 57.5%). The 2 RCTs lasting 10 weeks or more gave an odds ratio of response to treatment of 4.41 (95% confidence interval, 1.38 to 14.07). In 8 open studies identified, the same pattern of response was seen. The main treatment-emergent side effects reported were extrapyramidal side effects and raised serum prolactin.

CONCLUSIONS

Augmentation of clozapine with another antipsychotic drug in patients with schizophrenic illness that has partially responded to clozapine is worthy of an individual clinical trial. This trial may need to be longer than the 4 to 6 weeks usually recommended for acute antipsychotic monotherapy.

Adjunctive Treatment With Risperidone in Clozapine-Resistant Schizophrenia

OBJECTIVES

Long-term studies show that 47% to 63% of schizophrenic patients treated with clozapine fail to respond after 12 years of treatment. Such high rates of resistance justify the growing interest in therapeutic strategies based on enhancing the effect of clozapine with other antipsychotics. The combination of clozapine and risperidone in the treatment of partial responders to clozapine has been one of those receiving most interest from research.

METHODS AND RESULTS

The present work reports the case of a 26-year-old man, diagnosed with schizophrenia who, after treatment with clozapine at appropriate doses over 12 weeks without observable response, showed a marked and sustained improvement after the addition of risperidone to the clozapine treatment. We also present a detailed review of publications related to the therapeutic combination of clozapine and risperidone in clozapine-resistant schizophrenia.

CONCLUSIONS

Despite the contradictory nature of the published data, our results are in support of other work reporting that treatment with a combination of clozapine and risperidone, apart from being well tolerated, may constitute an effective alternative in this type of patient. Nevertheless, there is a need for further, controlled studies, with larger samples, with a view to drawing definitive conclusions and making specific recommendations.

The potential role of lamotrigine in schizophrenia

RATIONALE

Atypical antipsychotic drugs are the drugs of choice for the treatment of schizophrenia. However, despite advances, no treatments have been established for patients who fail to improve with the most effective of these, clozapine. The inhibition of dopamine transmission through blockade of dopamine D2 receptors is considered to be essential for antipsychotic efficacy, but it is postulated that modulation of glutamate transmission may be equally important. In support of this, symptoms similar to schizophrenia can be induced in healthy volunteers using N-methyl-D-aspartate (NMDA) antagonist drugs that are also known to enhance glutamate transmission. Furthermore, lamotrigine, which can modulate glutamate release, may add to or synergise with atypical antipsychotic drugs, some of which may themselves modulate glutamate transmission.

OBJECTIVES

We examine the evidence for the efficacy of lamotrigine. We consider how this fits with a glutamate neuron dysregulation hypothesis of the disorder. We discuss mechanisms by which lamotrigine might influence neuronal activity and glutamate transmission, and possible ways in which the drug might interact with antipsychotic medications.

RESULTS

Data from four clinical studies support the efficacy of adjunctive lamotrigine in the treatment of schizophrenia. In addition, and consistent with a glutamate neuron dysregulation hypothesis of schizophrenia, lamotrigine can prevent the psychotic symptoms or behavioural disruption induced by NMDA receptor antagonists in healthy volunteers or rodents.

CONCLUSIONS

The efficacy of lamotrigine is most likely explained within the framework of a glutamate neuron dysregulation hypothesis, and may arise primarily through the drugs ability to influence glutamate transmission and neural activity in the cortex. The drug is likely to act through inhibition of voltage-gated sodium channels, though other molecular interactions cannot be ruled out. Lamotrigine may add to or synergise with some atypical antipsychotic drugs acting on glutamate transmission; alternatively, they may act independently on glutamate and dopamine systems to bring about a combined therapeutic effect. We propose new strategies for the treatment of schizophrenia using a combination of anti-dopaminergic and anti-glutamatergic drugs.

Investigation of the effects of lamotrigine and clozapine in improving reversal-learning impairments induced by acute phencyclidine and D-amphetamine in the rat

RATIONALE

Phencyclidine (PCP), a glutamate/N-methyl-D-aspartate (NMDA) receptor antagonist, has been shown to induce a range of symptoms similar to those of patients with schizophrenia, while D-amphetamine induces predominantly positive symptoms. Previous studies in our laboratory have shown that PCP can selectively impair the performance of an operant reversal-learning task in the rat. Furthermore, we found that the novel antipsychotic ziprasidone, but not the classical antipsychotic haloperidol, could prevent the PCP-induced deficit.

OBJECTIVES

The aim of the present study was to validate the model further using the atypical antipsychotic clozapine and then to investigate the effects of lamotrigine, a broad-spectrum anticonvulsant that is known to reduce glutamate release in vitro and is able to prevent ketamine-induced psychotic symptoms in healthy human volunteers. A further aim was to compare effects of PCP and D-amphetamine in the test and investigate the effects of the typical antipsychotic haloperidol against the latter.

METHODS

Female hooded-Lister rats were food deprived and trained to respond for food in a reversal-learning paradigm.

RESULTS

PCP at 1.5 mg/kg and 2.0 mg/kg and D-amphetamine at 0.5 mg/kg significantly and selectively impaired performance in the reversal phase of the task. The cognitive deficit induced by 1.5 mg/kg PCP was attenuated by prior administration of lamotrigine (20 mg/kg and 30 mg/kg) or clozapine (5 mg/kg), but not haloperidol (0.05 mg/kg). In direct contrast, haloperidol (0.05 mg/kg), but not lamotrigine (25 mg/kg) or clozapine (5 mg/kg), prevented a similar cognitive impairment produced by D-amphetamine (0.5 mg/kg).

CONCLUSIONS

Our findings provide further data to support the use of PCP-induced disruption of reversal learning in rodents to investigate novel antipsychotic drugs. The results also provide evidence for different mechanisms of PCP and D-amphetamine-induced disruption of performance in the test, and their different sensitivities to typical and atypical antipsychotic drugs.

Combination of "atypical" antipsychotic medication in the management of treatment-resistant schizophrenia and schizoaffective disorder

BACKGROUND

This article reviews the published clinical data on treatment-resistant schizophrenic and schizoaffective patients managed with combinations of "atypical" antipsychotic medication.

METHOD

A computerized MEDLINE literature search covering an 18-year period (1985-2003) was conducted. All pertinent papers on the subject of the use of combination "atypical" antipsychotic medication in the management of treatment-resistant schizophrenia and schizoaffective disorder were obtained with subsequent analysis and discussion of the retrieved data.

RESULTS

The search identified 29 case reports and case series reports (172 patients) and one double-blind placebo-controlled trial (28 patients) describing the use of combination "atypical" antipsychotic medication (clozapine-risperidone; clozapine-sulpiride; clozapine-olanzapine; clozapine-quetiapine; olanzapine-sulpiride; olanzapine-quetiapine; risperidone-olanzapine; risperidone-quetiapine) in the treatment of resistant schizophrenic and schizoaffective patients. An overview of results suggests that the combinations were beneficial in the described patients with reduction of positive symptoms and occasionally negative symptoms. Significant adverse effects, while rare, were reported in a few cases and did not appear to different in nature from those managed on monotherapeutic regimens.

CONCLUSION

Combinations of "atypical" antipsychotic medications are well tolerated and may be effective in the management of treatment refractory schizophrenia and schizoaffective disorder. However, further double-blind placebo-controlled trials are required in order to test and confirm these observations.

Managing patients with "treatment-resistant" schizophrenia

Patients who fail to respond adequately to pharmacological treatment present an ongoing therapeutic challenge. The term "incomplete recovery" (IR) is preferred to the current term "treatment resistance" to describe these patients. IR should be considered from a multidimensional perspective that includes a broad range of symptoms and functional disabilities that are relevant to schizophrenia. The approach to the incompletely recovered patient needs to be systematic, with consideration given to the factors that may hamper recovery. "Atypical" (second-generation) antipsychotic drugs target various domains of symptoms relevant to IR. Adjunctive treatment strategies (eg, mood stabilisers, antidepressants, combinations of antipsychotics) may be useful, but should be undertaken in specialist psychiatric settings. Although pharmacological treatment is a necessary first step in managing incompletely recovered patients, adjunctive psychosocial interventions are needed to optimise treatment success.

A follow-up study of a population of schizophrenic patients treated with clozapine

1. Clozapine is a dibenzodiazepine neuroleptic which presents the advantage of not having undesirable neurological side-effects. Its efficacy for the treatment of the symptoms of schizophrenia is known, but the use of clozapine is limited to treatment-resistant schizophrenic patients as it induces agranulocytosis with a higher incidence than that of other neuroleptic drugs. 2. The present study was designed in order to evaluate the benefit/risk of chronic treatment. The analysis was performed using the files of schizophrenic patients. These patients were not stabilized by a classical neuroleptic treatment and/or presented individual secondary effects. 3. Clozapine induced neutropenia and 1 case of agranulocytosis in 3 females. Analysis of leukocyte expression highlighted some premonitory symptoms in patients who presented neutropenia. The observation of 2 to 3 early successive peaks in leukocyte expression (between the third and tenth week of treatment) could be predictive of neutropenia in the 3 to 4 months of treatment. 4. The patients who presented a lower leukocyte base-line following a peak had a higher risk, of developing neutropenia. This might explain some late accidents beyond the first six months of treatment. 5. The present study confirmed the advantages of clozapine treatment and demonstrated that the risk of neutropenia may be diminished by the detection of premonitory symptoms and the early monitoring of patients at risk i.e. female patients and subjects with a lower leukocyte base-line.

Hospital care pathways for patients with schizophrenia

Greater emphasis is being placed on reducing clinical variation in managing patient groups in the reformed National Health Service (NHS) in the United Kingdom (UK). The use of a care pathway to enable greater control over the process and quality of care will be explored for patients suffering from schizophrenia. The paper addresses three main factors for the development of care pathways for people suffering from schizophrenia: predictability of the illness; nature of standardized care; and role autonomy. It is argued that the diagnosis of schizophrenia does not lend itself easily to predicting care and treatment within a care pathway framework. However, a care pathway may bring other benefits, such as standardized care and a greater control over the delivery of care. Development and implementation of hospital care pathways require extensiv research. Qualitative research directions are advocated due to the possib difficulties of conducting an experimental study.

Risperidone and clozapine combination for the treatment of refractory schizophrenia

Clozapine is the most widely used antipsychotic drug for the treatment of refractory schizophrenia. Here we report the case of two residual schizophrenic patients refractory to conventional antipsychotics who showed a poor response to atypical antipsychotics. The combination of risperidone and clozapine produced a noticeable improvement in the patients' clinical status and a shortening of the treatment response latency.

Pharmacological treatment of schizophrenia resistant to first-line treatment: a critical systematic review and meta-analysis

Schizophrenia resistance to conventional antipsychotics is a common phenomenon. In 5-25% of cases, satisfactory treatment response is not achieved, and intolerance to conventional antipsychotics occurs in 5-20% of patients. Numerous reasons for refractoriness have been proposed. However, up to now only a few pharmacological agents have been found useful in the treatment of schizophrenia resistant to conventional antipsychotics. This paper critically reviews quality-assessed trials on the pharmacological treatment of refractory schizophrenia. Randomized blinded trials of conventional antipsychotics at high doses, atypical antipsychotics, lithium, propranolol, and agents not traditionally used in the treatment of schizophrenia are reviewed. On the basis of the methodologically sound studies included, we conclude that only clozapine has proved to be clinically effective in the treatment of refractory schizophrenia. In the short term, the odds ratio for clinical improvement on clozapine treatment when compared to conventional treatment is calculated to be 2.4 (95% confidence interval [CI] 1.7-3.5) and the number of patients needed to treat (NNT) is 7 (95% CI 5-13). In single inconclusive trials, olanzapine and risperidone have been found as effective as clozapine. In order to establish the usefulness of other pharmacological treatments, more randomized clinical trials are needed.