Combination of Clozapine and Ziprasidone in Treatment-Resistant Schizophrenia

Augmentation of Antipsychotic Medications with Low-Dose Clozapine in Treatment-Resistant Schizophrenia-Case Reports and Discussion

Treatment resistance in schizophrenia is often encountered in clinical practice, with clozapine usually recommended as the appropriate therapy. However, where clozapine proves ineffective or cannot be tolerated due to side effects, treatment options are limited. In patients within forensic mental health services, residual symptomatology often presents a barrier to discharge and can have lasting effects on prospects for rehabilitation as well as risk to self and others. This paper presents a review of the relevant literature and three cases of a novel approach, utilising clozapine in doses usually considered subtherapeutic, in combination with the primary antipsychotic treatment. In all three patients, it improved clinical efficacy as well as tolerability, resulting in improvement that allowed discharge from the forensic hospital.

Characteristics and definitions of ultra-treatment-resistant schizophrenia - A systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to characterize ultra-treatment-resistant Schizophrenia also known as clozapine-resistant schizophrenia (CRS) patients across clozapine combination and augmentation trials through demographic and clinical baseline data. Furthermore, we investigated the variability and consistency in CRS definitions between studies.

METHODS

Systematic searches of articles indexed in PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL) and PsycINFO were conducted in March 2020. 1541 randomized and non-randomized clinical trials investigating pharmacological and non-pharmacological clozapine add-on strategies were screened and a total of 71 studies were included. The primary outcome was the overall symptom score at baseline, measured with Positive and Negative Syndrome Scale (PANSS) total or Brief Psychiatric Rating Scale (BPRS) total scores.

RESULTS

Data from 2731 patients were extracted. Patients were overall moderately ill with a mean PANSS total score at baseline of 79.16 (±7.52), a mean duration of illness of 14.64 (±4.14) years with a mean clozapine dose of 436.94 (±87.47) mg/day. Illness severity data were relatively homogenous among patients independently of the augmentation strategy involved, although stark geographical differences were found. Overall, studies showed a large heterogeneity of CRS definitions and insufficient guidelines implementation.

CONCLUSIONS

This first meta-analysis characterizing CRS patients and comparing CRS definitions revealed a lack of consistent implementation of a CRS definition from guidelines into clinical trials, compromising the replicability of the results and their applicability in clinical practice. We offer a new score modeled on a best practice definition to help future trials increase their reliability.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

Antipsychotic Polypharmacy and Corrected QT Interval: A Systematic Review

OBJECTIVE

It remains unclear whether antipsychotic polypharmacy, a common clinical practice, is related to an increased risk of corrected time between start of Q wave and end of T wave (QTc) interval prolongation. We conducted a systematic review of the literature to address this important issue.

METHOD

A systematic literature search was conducted in October 2014, using MEDLINE, Embase, and PsycINFO. Studies and case reports were included if they reported QTc intervals or QTc interval changes before and after antipsychotic polypharmacy or QTc intervals in both antipsychotic polypharmacy and monotherapy groups.

RESULTS

A total of 21 articles (10 clinical trials, 4 observational studies, and 7 case reports) met inclusion criteria. The clinical trials have shown that a combination treatment with risperidone or pimozide is not obviously related to an increase in QTc interval, whereas ziprasidone or sertindole combined with clozapine may prolong QTc interval. Among the 4 observational studies, antipsychotic polypharmacy was not clearly associated with QTc prolongation in 3 studies, each cross-sectional. In contrast, one prospective study showed a significant increase in QTc interval following antipsychotic coadministration. The case reports indicated an increased risk of QTc prolongation in at least some patients receiving antipsychotic polypharmacy.

CONCLUSIONS

Currently available evidence fails to confirm that antipsychotic polypharmacy worsens QTc prolongation in general, although the evidence is scarce and inconsistent. Clinicians are advised to remain conservative in resorting to antipsychotic polypharmacy, as a combination of some QTc-prolongation liable antipsychotics may further prolong QTc interval, and efficacy supporting the clinical benefits of antipsychotic polypharmacy is equivocal, at best.

Ziprasidone as Adjunctive Therapy in Severe Bipolar Patients Treated with Clozapine

Aim. To confirm the efficacy and tolerability of ziprasidone as adjunctive therapy in bipolar patients partially responding to clozapine or with persisting negative symptoms, overweight, or with metabolic syndrome. Methods. Eight patients with psychotic bipolar disorder were tested with the BPRS, the HAM-D, and the CGI at T0 and retested after 2 weeks (T1). Plasma clozapine and norclozapine levels and BMI were tested at T0 and T1. Results. Ziprasidone was well tolerated by all the patients. BPRS and HAM-D scores were reduced in all patients. BMI was reduced in patients with a BMI at T0 higher than 25. Plasma levels of clozapine and norclozapine showed an irregular course.

Augmentation of clozapine with ziprasidone in refractory schizophrenia: a double-blind, placebo-controlled study

The present 16-week double-blind, randomized, placebo-controlled trial was aimed to explore the efficacy of ziprasidone add-on pharmacotherapy on clinical symptoms and cognitive functioning in 40 schizophrenic patients (active group, n = 20; placebo group, n = 20) with residual symptoms (Brief Psychiatric Rating Scale mean [SD] baseline total score in active group vs placebo, 40.4 [5.9] vs 37.9 [6.8]) despite receiving clozapine monotherapy at the highest tolerated dosage. The results obtained evidenced that ziprasidone augmentation of clozapine significantly reduced Positive and Negative Syndrome Scale "Negative" (P = 0.006, mean change [SD] in active group vs placebo, -2.7 [2.3] vs 1.1 [2.1], Cohen d = 1.7) and "General Psychopathology" (P = 0.009, mean change [SD] in active group vs placebo, -5.3 [3.8] vs -0.7 [2.0], Cohen d = 1.5). Regarding cognitive domains, ziprasidone was more effective than placebo in improving semantic fluency (P < 0.0001, mean change [SD] in active group vs placebo, 4.4 [3.5] vs -0.1 [4.1], Cohen d = 1.2). Ziprasidone had only a small effect on prolongation of heart-rate corrected QT interval (QTc) of the electrocardiogram, not significantly different from placebo (QTc milliseconds, mean [SD], week 16 in active group vs placebo, 408.17 [20.85] vs 405.45 [17.11], P = 0.321); within-group comparison revealed that QTc prolongation induced by ziprasidone was statistically significant (baseline vs week 16, P = 0.002). Ziprasidone added to clozapine was effective on negative and cognitive symptoms, although it may be proposed as a helpful treatment in schizophrenia, mainly for those patients who partially respond to clozapine monotherapy.

Treating symptomatic hyperprolactinemia in women with schizophrenia: presentation of the ongoing DAAMSEL clinical trial (Dopamine partial Agonist, Aripiprazole, for the Management of Symptomatic ELevated prolactin)

Prolactin elevations occur in people treated with antipsychotic medications and are often much higher in women than in men. Hyperprolactinemia is known to cause amenorrhea, oligomenorrhea, galactorrhea and gynecomastia in females and is also associated with sexual dysfunction and bone loss. These side effects increase risk of antipsychotic nonadherence and suicide and pose significant problems in the long term management of women with schizophrenia. In this manuscript, we review the literature on prolactin; its physiology, plasma levels, side effects and strategies for treatment. We also present the rationale and protocol for an ongoing clinical trial to treat symptomatic hyperprolactinemia in premenopausal women with schizophrenia. More attention and focus are needed to address these significant side effects and help the field better personalize the treatment of women with schizophrenia.

Safety and tolerability of antipsychotic polypharmacy

INTRODUCTION

Antipsychotic polypharmacy (APP), the concomitant use of ≥ 2 antipsychotics, is common in clinical practice. Prior reviews have focused on the efficacy of APP, but no systematic review exists regarding the safety and tolerability of this practice.

AREAS COVERED

A systematic review of adverse effects associated with APP was conducted to prepare this review; case series with ≥ 2 patients, chart reviews, naturalistic, database, cohort and randomized studies that reported on the association between APP in general or specific APP combinations and global or specific adverse effect were included. Methodological limitations of available studies are discussed and recommendations for clinicians and future research are provided.

EXPERT OPINION

Across mostly small and uncontrolled studies, APP has been associated with increased global side effect burden, rates of Parkinsonian side effects, anticholinergic use, hyperprolactinemia, sexual dysfunction, hypersalivation, sedation/somnolence, cognitive impairment and diabetes. Effects on akathisia and mortality were inconclusive. Although some combinations, particularly aripiprazole augmentation of an agent with greater side effect burden, may reduce weight gain, dyslipidemia, hyperprolactinemia and sexual dysfunction, APP should remain a last-resort treatment option after monotherapy, switching and non-antipsychotic combinations have failed. More data are needed to further inform the individualized risk-benefit evaluation of APP.

Antipsychotic polypharmacy in schizophrenia: benefits and risks

Antipsychotic polypharmacy refers to the co-prescription of more than one antipsychotic drug for an individual patient. Surveys of prescribing in psychiatric services internationally have identified the relatively frequent and consistent use of combined antipsychotics, usually for people with established schizophrenia, with a prevalence of up to 50% in some clinical settings. A common reason for prescribing more than one antipsychotic is to gain a greater or more rapid therapeutic response than has been achieved with antipsychotic monotherapy. However, the evidence on the risks and benefits for such a strategy is equivocal, and not generally considered adequate to warrant a recommendation for its use in routine clinical practice in psychiatry. Combined antipsychotics are a major contributor to high-dose prescribing, associated with an increased adverse effect burden, and of limited value in helping to establish the optimum maintenance regimen for a patient. The relatively widespread use of antipsychotic polypharmacy identified in cross-sectional surveys reflects not only the addition of a second antipsychotic to boost therapeutic response, but also the use of as-required antipsychotic medication (mainly to treat disturbed behaviour), gradual cross-titration while switching from one antipsychotic to another, and augmentation of clozapine with a second antipsychotic where the illness has failed to respond adequately to an optimized trial of clozapine. This review addresses the clinical trial data and other evidence for each of these pharmacological approaches. Also reviewed are examples of systematic, practice-based interventions designed to reduce the prevalence of antipsychotic polypharmacy, most of which have met with only modest success. Guidelines generally agree that if combined antipsychotics are prescribed to treat refractory psychotic illness, this should be after other, evidence-based, pharmacological treatments such as clozapine have been exhausted. Further, their prescription for each patient should be in the context of an individual trial, with monitoring of the clinical response and adverse effects, and appropriate physical health monitoring.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: recommendations from the British Association for Psychopharmacology

These guidelines from the British Association for Psychopharmacology address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting, involving experts in schizophrenia and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from the participants and interested parties, and cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. The practice recommendations presented are based on the available evidence to date, and seek to clarify which interventions are of proven benefit. It is hoped that the recommendations will help to inform clinical decision making for practitioners, and perhaps also serve as a source of information for patients and carers. They are accompanied by a more detailed qualitative review of the available evidence. The strength of supporting evidence for each recommendation is rated.

Polypharmacy in schizophrenia

PURPOSE OF REVIEW

Although most guidelines recommend monotherapy in schizophrenia, the combined application of multiple psychotropic agents is very common, especially in treatment-refractory cases. We review the empirical basis supporting these attempts and their relevance for clinical practice.

RECENT FINDINGS

Polypharmacy intends to address different aspects of treatment resistance, most importantly insufficient response of psychotic positive and negative symptoms, but also cognitive disturbances, affective comorbidity, obsessive-compulsive syndromes and side-effects of antipsychotic drugs. This review summarizes the current state of evidence of combined antipsychotic treatment strategies and the augmentation of antipsychotics with mood stabilizers, antidepressants and experimental substances.

SUMMARY

In general, rigorous data on combination therapy in schizophrenia are rare and further randomized controlled trials, naturalistic trials and head-to-head-trials are necessary. Some evidence supports a combination of antipsychotics and antidepressants for negative symptoms and comorbid major depressive episodes. The add-on of lithium and mood stabilizers lacks compelling evidence, but might be beneficial for specific subgroups. For treatment-resistant cognitive symptoms, antipsychotic medication should be combined with cognitive remediation, as no pharmacological add-on strategy has gained convincing evidence so far. Treatment-emergent positive and/or negative symptoms under clozapine monotherapy might benefit from adding a second atypical substance.

Ziprasidone vs clozapine in schizophrenia patients refractory to multiple antipsychotic treatments: the MOZART study

This 18-week, randomized, flexible-dose, double-blind, double-dummy trial evaluated ziprasidone as an alternative to clozapine in treatment-refractory schizophrenia patients. Patients had a DSM-IV diagnosis of schizophrenia, a history of resistance and/or intolerance to at least three acute cycles with different antipsychotics given at therapeutic doses, PANSS score >or= 80, and CGI-S score >or= 4. Patients were randomized to ziprasidone (80-160 mg/day, n = 73) or clozapine (250-600 mg/day, n = 74). On the primary ITT-LOCF analysis, baseline-to-endpoint decreases in PANSS total scores were similar in the ziprasidone (- 25.0 +/- 22.0, 95% CI - 30.2 to - 19.8) and clozapine (- 24.5 +/- 22.5, 95% CI - 29.7 to - 19.2) groups. A progressive and significant reduction from baseline in PANSS total score was observed from day 11 in both study arms. There were also significant improvements on PANSS subscales, CGI-S, CG-I, CDSS, and GAF, without between-drug differences. The two treatment groups had similar rates of early discontinuations due to AEs. AEs were mostly of similar mild-moderate severity in the two groups. There were also no detrimental effects on prolactin, renal and liver function, hematology, and cardiovascular parameters. However, ziprasidone but not clozapine showed a significant reduction of SAS and AIMS scores. Moreover, when compared with clozapine, ziprasidone also had a more favorable metabolic profile, with significant endpoint differences in weight, fasting glucose, total cholesterol, LDL cholesterol, and triglycerides. In conclusion, this trial indicates that both ziprasidone and clozapine, having comparable efficacy coupled with satisfactory general safety and tolerability, may be regarded as valuable options for the short-term treatment of difficult-to-treat schizophrenia patients with a history of multiple resistance and/or intolerance to antipsychotics. The more favorable metabolic profile of ziprasidone may represent an added value that could guide clinicians, at least in the presence of patients at high risk for metabolic disorders.

Ziprasidone vs clozapine in schizophrenia patients refractory to multiple antipsychotic treatments: the MOZART study

This 18-week, randomized, flexible-dose, double-blind, double-dummy trial evaluated ziprasidone as an alternative to clozapine in treatment-refractory schizophrenia patients. Patients had a DSM-IV diagnosis of schizophrenia, a history of resistance and/or intolerance to at least three acute cycles with different antipsychotics given at therapeutic doses, PANSS score >or=80, and CGI-S score >or=4. Patients were randomized to ziprasidone (80-160 mg/day, n=73) or clozapine (250-600 mg/day, n=74). On the primary ITT-LOCF analysis, baseline-to-endpoint decreases in PANSS total scores were similar in the ziprasidone (-25.0+/-22.0, 95% CI -30.2 to -19.8) and clozapine (-24.5+/-22.5, 95% CI -29.7 to -19.2) groups. A progressive and significant reduction from baseline in PANSS total score was observed from day 11 in both study arms. There were also significant improvements on PANSS subscales, CGI-S, CG-I, CDSS, and GAF, without between-drug differences. The two treatment groups had similar rates of early discontinuations due to AEs. AEs were mostly of similar mild-moderate severity in the two groups. There were also no detrimental effects on prolactin, renal and liver function, hematology, and cardiovascular parameters. However, ziprasidone but not clozapine showed a significant reduction of SAS and AIMS scores. Moreover, when compared with clozapine, ziprasidone also had a more favorable metabolic profile, with significant endpoint differences in weight, fasting glucose, total cholesterol, LDL cholesterol, and triglycerides. In conclusion, this trial indicates that both ziprasidone and clozapine, having comparable efficacy coupled with satisfactory general safety and tolerability, may be regarded as valuable options for the short-term treatment of difficult-to-treat schizophrenia patients with a history of multiple resistance and/or intolerance to antipsychotics. The more favorable metabolic profile of ziprasidone may represent an added value that could guide clinicians, at least in the presence of patients at high risk for metabolic disorders.

Efficacy and tolerability of ziprasidone versus risperidone as augmentation in patients partially responsive to clozapine: a randomised controlled clinical trial

Patients suffering from schizophrenic psychoses sometimes insufficiently respond to antipsychotic monotherapy and then combination approaches are preferred. We aimed in validating the add-on of ziprasidone and risperidone to clozapine, and we performed a randomised head-to-head trial. Patients with partial response to clozapine were randomly attributed to augmentation with ziprasidone (n = 12) or risperidone (n = 12). Efficacy assessments included the Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Negative Symptoms (SANS), the Hamilton Depression Scale (HAMD), the Clinical Global Impression (CGI) and the Global Assessment of Functioning (GAF). Furthermore, several safety and tolerability measures were obtained. After six weeks, both groups showed significant reductions of positive and negative symptoms. In addition, affective state, psychosocial functioning and clozapine side effects improved without significant differences between the groups. Both approaches were well tolerated. However, the ziprasidone group experienced a small elongation of the QTc interval and a reduction of extrapyramidal symptoms. Patients under clozapine-risperidone therapy developed a rise of serum prolactin levels. The clozapine augmentation with ziprasidone or risperidone resulted in significant psychopathological improvements. The side effects differed between the treatment groups. Further head-to-head comparisons of atypical antipsychotics as add-on to clozapine are necessary.

Antipsychotic polypharmacy in patients with schizophrenia in a brief hospitalization unit

INTRODUCTION

Antipsychotic monotherapy is considered the gold standard in pharmacological treatment of schizophrenia and other psychotic disorders. Only 2 of the main clinical guides recommend the use of antipsychotic polypharmacy (AP) for those patients refractory to monotherapy. Nonetheless, there is a large rate of studies, conducted in many different settings, showing that AP is more frequent as would be expected attending experts' recommendations.

METHODS

In this retrospective study, we review all the psychotropic drugs dispensed to inpatients of a brief hospitalization psychiatric unit diagnosed as having schizophrenia or schizoaffective disorder (International Statistical Classification of Diseases, 10th Revision) at time of discharge in the year 2005. These included a total of 209 patients older than 18 years.

RESULTS

Of the 209 studied patients, 55.5% were discharged under AP treatment. Inpatients were given a mean of 3.06 psychotropic drugs and a mean of 1.61 antipsychotics at the time of hospital discharge. A total of 33.2% of the studied patients got anticholinergic drugs, and 66.2% were given benzodiazepines. The most prevalent combination of drugs was intramuscular long-acting risperidone plus an atypical antipsychotic. Amisulpride was the most used antipsychotic as adjuvant treatment.

CONCLUSIONS

Despite different clinical guidelines, AP is a common pharmacological strategy as it is shown in our study and in the reviewed literature. Data in our study indicate that the observed rates of AP cannot exclusively be attributed to the treatment of patients with clozapine-resistant schizophrenia.

Polypharmacy with second-generation antipsychotics: a review of evidence

OBJECTIVE

The objective of this study was to review the prevalence of polypharmacy with second-generation antipsychotics (SGAs) in clinical practice, pharmacological reasons for such practice, and the evidence for and against such polypharmacy.

METHODS

Clinical trial reports, case reports, and reviews were identified by a PubMed literature search from 1966 through October 2006, with retrieved publications queried for additional references. We excluded reports on augmentation with non-antipsychotic medications and polypharmacy involving combinations of SGAs and first-generation (conventional) antipsychotics (FGAs) or combinations of two FGAs. We identified 75 reports concerning SGA polypharmacy, from which we extracted data on study design, sample size, medications, rating scales, outcome, and conclusions. Data from randomized controlled trials and larger case series are presented in detail and case reports are briefly discussed.

CONCLUSIONS

Polypharmacy with SGAs is not uncommon, with prevalence varying widely (3.9% to 50%) depending on setting and patient population, despite limited support from blinded, randomized, controlled trials or case reports that employed an A-B-A (monotherapy-combination therapy-monotherapy) design and adequate dosing and duration of treatment. Rather than prohibiting or discouraging co-prescription of SGAs, needs of patients and clinicians should be addressed through evidence-based algorithms. Based on unmet clinical needs and modest evidence from case reports, combinations of two SGAs may merit future investigation in efficacy trials involving patients with schizophrenia who have treatment-resistant illness (including partial response) or who are responsive to treatment but develop intolerable adverse effects. Other areas that may merit future research are efficacy of SGA polypharmacy for schizophrenia accompanied by comorbid conditions (eg, anxiety, suicidal or self-injurious behavior, aggression) and for reducing length of stay in acute care settings.

Combined antipsychotic treatment involving clozapine and aripiprazole

Treatment resistance is considered a challenging problem of antipsychotic pharmacotherapy. In such cases, combination approaches are commonly used, for instance the add-on of aripiprazole to clozapine. This review aims at giving an overview of the present knowledge on this strategy. We performed a keyword-based screening of databases (including November 2007) and evaluated the data in a systematic manner. The courses of 94 patients were reported in 11 publications. At a mean dosage of 20.5 mg/day, aripiprazole achieved clinical improvement of psychotic symptoms and facilitated a dose reduction of clozapine from 476.7 to 425.1 mg/day. In parallel, clozapine serum levels decreased from 611 to 523 ng/ml. No pharmacokinetic interactions were reported, and clozapine-induced side effects ameliorated. However, single cases of extrapyramidal side effects occurred. The combination of clozapine and aripiprazole follows a neurobiological rationale and appears to be effective and tolerable. The results of placebo-controlled trials might allow further insight into the benefits and risks of this strategy.

Clozapine-induced myocarditis after long-term treatment: case presentation and clinical perspectives

Clozapine is the drug of choice for treatment-resistant schizophrenia. Prompted by a patient who developed reversible clozapine-induced myocarditis after long-term treatment with clozapine for several years for chronic-resistant schizophrenia, we undertook a review of the relevant literature. Concerning the myocarditis, the patient recovered rapidly by withdrawal of clozapine and with supportive management. Psychiatric stabilisation of the patient was at least possible with a combination of quetiapine (600 mg) and amisulpride (800 mg). Well-designed studies with the aim to specifically investigate treatment options after clozapine are limited and clinical possibilities are discussed in this paper. Olanzapine and combinations using non-clozapine atypical neuroleptics have partly shown improvement, whereas evidence for successful augmentation with mood stabilisers, anticonvulsants or electroconvulsive therapy in treatment-resistant schizophrenia is limited.

Benefits and risks of antipsychotic polypharmacy: an evidence-based review of the literature

Combination antipsychotic prescription is an increasingly common practice in clinical psychiatry. This clinical practice is at odds with clinical guidelines promoting antipsychotic monotherapy. Moreover, there has been increased concern over the safety profile of atypical antipsychotics in the last 10-15 years. We reviewed the literature on antipsychotic combinations with a focus on safety and efficacy. Multiple electronic database searches were complemented by relevant bibliography cross-checking and expert discussions. The review showed a literature that is dominated by case reports and uncontrolled studies. Polypharmacy was unequally studied, with some recent combinations (i.e. clozapine and risperidone) being extensively, albeit inconclusively, studied and other more commonly used combinations (first- with second-generation agents) receiving little attention. From an evidence-based perspective, further trials of antipsychotic association of sufficient power to address safety issues are needed before recommending any antipsychotic combination. Particular weaknesses of the present literature are low number of participants, lack of adequate control of confounding variables, short duration of experimental follow-up and inadequate monitoring of potential adverse effects.

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.

Benefits of combining aripiprazole to clozapine: three case reports

OBJECTIVE

A substantial number of patients treated with clozapine shows insufficient response. The author presents the results of adding aripiprazole in patients resistant to clozapine.

METHOD

Three cases of individuals with psychotic symptoms despite clozapine use and with significant side effects that were treated via this combination are presented. Response was evaluated by clinical assessment.

RESULTS

Good clinical results were obtained in all three patients, with improvement of psychotic symptoms and of some of the side effects of clozapine.

CONCLUSION

The findings from this case series suggest that adjunctive therapy with aripiprazole can be of benefit for treating clozapine resistant schizophrenic patients.