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

Adjunctive risperidone for partially responsive people with schizophrenia treated with clozapine

The large numbers of partial clozapine responders represent a major therapeutic challenge. Unfortunately, there are no clear data to support how best to treat these patients. This study examines the efficacy and safety of adjunctive risperidone in a well-defined treatment-resistant population optimally treated with clozapine. A total of 69 inpatients and outpatients with DSM-IV schizophrenia or schizoaffective disorder entered a 16-week double-blind, placebo-controlled, randomized clinical trial. Of them, 33 participants were randomized to risperidone and 36 were randomized to placebo. There was no significant group difference in the predefined response criteria. There were modest group differences for Brief Psychiatric Rating Scale (BPRS) positive symptoms, which were significant in the completer analysis (F=5.70; df=1, 70.3; p=0.02; ES=0.27) but not the intent-to-treat (ITT) analyses (F=3.01; df=1, 77.5; p=0.09; ES=0.19). A similar pattern was found for the BPRS total score, with the completer analysis showing a significant improvement in the risperidone group (F=5.21; df=1, 64.9; p=0.03; ES=0.27), whereas the ITT analysis was not significant (F=3.52; df=1, 71.3; p=0.06; ES=0.22). In addition, there was a small, but significant, group difference for negative symptoms, as measured by the SANS total score, which favored the risperidone group (F=5.67; df=1, 78.7; p=0.02; ES=0.24). There were no significant group differences on safety measures, including neuropsychological test and extrapyramidal symptom scores. A significant elevation of prolactin in the risperidone group was observed. The study results suggest that adjunctive risperidone may have a modest benefit for treatment-resistant clozapine patients. The study results are discussed in the context of previous double-blind studies of adjunctive risperidone. (clinicaltrials.gov, trial number: NCT00056498).

The combined use of risperidone long-acting injection and clozapine in patients with schizophrenia non-adherent to clozapine: a case series

Poor adherence to clozapine treatment represents an important problem in clinical practice because additional useful treatment options are unavailable. Although switching to risperidone long-acting injection (RLAI) has been recommended for those with compliance problems, this medication has been found to be less suitable for patients who previously received clozapine. Based on the suggested beneficial effects of RLAI, such as higher rates of treatment continuation and patient satisfaction, and the possible effectiveness of oral risperidone augmentation, it seems worthwhile to try RLAI augmentation for clozapine non-adherence. In this article, we present the cases of four patients with schizophrenia undergoing combined treatment with RLAI and clozapine for more than one year after multiple relapses related to clozapine non-adherence. Durations and frequencies of hospitalizations markedly declined after RLAI augmentation. Indeed, three patients receiving RLAI and clozapine for 1.2-3.5 years were never hospitalized during this period. The lengths of hospitalizations before and after augmenting with RLAI were 54.7 +/- 33.1 and 4.2 +/- 4.2 days/year, respectively. Participants also showed great improvements in social skills. These findings suggest the possible beneficial effects of RLAI augmentation in cases of clozapine nonadherence. However, controlled clinical trials are necessary to confirm whether RLAI augmentation represents a useful treatment option for patients who have not adhered to clozapine treatment.

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.

Augmentation of atypical antipsychotics with valproic acid. An open-label study for most difficult patients with schizophrenia

OBJECTIVE

Most difficult inpatients with schizophrenia are in serious needs but obviously underrepresented in clinical trials.

METHODS

Very challenging patients received open-label treatment with atypical antipsychotics concurrently augmented with valproic acid. The primary outcome was the newly developed Functional Assessment for Comprehensive Treatment of Schizophrenia (FACT-Sz). Patients improving more than 20 points were classified as responders.

RESULTS

Mean age and illness duration of 28 participants (22 male) were 42 y.o. and 20 years, respectively. They had spent a half of their life admitted after the onset. The average Brief Psychiatric Rating Scale (BPRS) and Clinical Global Impression-Severity (CGI-S) were very severe at 79 and 6.1, respectively, with the baseline Global Assessment of Functioning (GAF) of as low as 21. As a result of augmentation, there were nine responders, 12 partial responders, and seven non-responders including only two patients who got worse. The main antipsychotics were mostly either risperidone or olanzapine. Mean maximum oral dose and blood level of valproic acid were 1907 mg and 91.7 microg/ml, respectively. Overall significant improvements whilst to an inadequate degree were noted in clinical parameters. Valproate augmentation was generally well tolerated but serious adverse effects included thrombocytopenia, anaemia and sedation/falls.

CONCLUSIONS

While these preliminary results need to be tested against tenacious monotherapy or polypharmacy involving clozapine, augmenting atypical antipsychotics with valproic acid can be useful for very severe schizophrenia.

Advantages and disadvantages of combination treatment with antipsychotics ECNP Consensus Meeting, March 2008, Nice

TERMINOLOGY AND PRINCIPLES OF COMBINING ANTIPSYCHOTICS WITH A SECOND MEDICATION: The term "combination" includes virtually all the ways in which one medication may be added to another. The other commonly used terms are "augmentation" which implies an additive effect from adding a second medicine to that obtained from prescribing a first, an "add on" which implies adding on to existing, possibly effective treatment which, for one reason or another, cannot or should not be stopped. The issues that arise in all potential indications are: a) how long it is reasonable to wait to prove insufficiency of response to monotherapy; b) by what criteria that response should be defined; c) how optimal is the dose of the first monotherapy and, therefore, how confident can one be that its lack of effect is due to a truly inadequate response? Before one considers combination treatment, one or more of the following criteria should be met; a) monotherapy has been only partially effective on core symptoms; b) monotherapy has been effective on some concurrent symptoms but not others, for which a further medicine is believed to be required; c) a particular combination might be indicated de novo in some indications; d) The combination could improve tolerability because two compounds may be employed below their individual dose thresholds for side effects. Regulators have been concerned primarily with a and, in principle at least, c above. In clinical practice, the use of combination treatment reflects the often unsatisfactory outcome of treatment with single agents. ANTIPSYCHOTICS IN MANIA: There is good evidence that most antipsychotics tested show efficacy in acute mania when added to lithium or valproate for patients showing no or a partial response to lithium or valproate alone. Conventional 2-armed trial designs could benefit from a third antipsychotic monotherapy arm. In the long term treatment of bipolar disorder, in patients responding acutely to the addition of quetiapine to lithium or valproate, this combination reduces the subsequent risk of relapse to depression, mania or mixed states compared to monotherapy with lithium or valproate. Comparable data is not available for combination with other antipsychotics. ANTIPSYCHOTICS IN MAJOR DEPRESSION: Some atypical antipsychotics have been shown to induce remission when added to an antidepressant (usually a SSRI or SNRI) in unipolar patients in a major depressive episode unresponsive to the antidepressant monotherapy. Refractoriness is defined as at least 6 weeks without meeting an adequate pre-defined treatment response. Long term data is not yet available to support continuing efficacy. SCHIZOPHRENIA: There is only limited evidence to support the combination of two or more antipsychotics in schizophrenia. Any monotherapy should be given at the maximal tolerated dose and at least two antipsychotics of different action/tolerability and clozapine should be given as a monotherapy before a combination is considered. The addition of a high potency D2/3 antagonist to a low potency antagonist like clozapine or quetiapine is the logical combination to treat positive symptoms, although further evidence from well conducted clinical trials is needed. Other mechanisms of action than D2/3 blockade, and hence other combinations might be more relevant for negative, cognitive or affective symptoms. OBSESSIVE-COMPULSIVE DISORDER: SSRI monotherapy has moderate overall average benefit in OCD and can take as long as 3 months for benefit to be decided. Antipsychotic addition may be considered in OCD with tic disorder and in refractory OCD. For OCD with poor insight (OCD with "psychotic features"), treatment of choice should be medium to high dose of SSRI, and only in refractory cases, augmentation with antipsychotics might be considered. Augmentation with haloperidol and risperidone was found to be effective (symptom reduction of more than 35%) for patients with tics. For refractory OCD, there is data suggesting a specific role for haloperidol and risperidone as well, and some data with regard to potential therapeutic benefit with olanzapine and quetiapine. ANTIPSYCHOTICS AND ADVERSE EFFECTS IN SEVERE MENTAL ILLNESS: Cardio-metabolic risk in patients with severe mental illness and especially when treated with antipsychotic agents are now much better recognized and efforts to ensure improved physical health screening and prevention are becoming established.

Augmentation of clozapine with a second antipsychotic--a meta-analysis of randomized, placebo-controlled studies

OBJECTIVE

Inadequate response to clozapine treatment is frequently encountered in practice and augmentation strategies have been developed in an attempt to improve response. Aims of the study were to evaluate the therapeutic effect of adding an antipsychotic drug to clozapine treatment.

METHOD

Meta-analysis of randomized, placebo-controlled studies of antipsychotic augmentation of clozapine treatment.

RESULTS

Ten studies (including 522 subjects) met inclusion criteria. Antipsychotic augmentation showed significant benefit over the addition of placebo on only one outcome measure examined [mean effect size for rating scale score (BPRS/PANSS) -0.180, 95% CI -0.356 to -0.004]. Antipsychotic augmentation showed no advantage on withdrawals from trials (risk ratio 1.261, 95% CI 0.679-2.345) or on CGI scores (effect size -0.661, 95% CI -1.475 to 0.151). Duration of study was not associated with outcome (P = 0.95). There was no evidence of publication bias.

CONCLUSION

In studies lasting up to 16 weeks, the addition of an antipsychotic to clozapine treatment has marginal therapeutic benefit. Longer and larger trials are necessary to demonstrate the precise therapeutic utility of antipsychotic co-therapy with clozapine.

Rationale and design of an independent randomised controlled trial evaluating the effectiveness of aripiprazole or haloperidol in combination with clozapine for treatment-resistant schizophrenia

BACKGROUND

One third to two thirds of people with schizophrenia have persistent psychotic symptoms despite clozapine treatment. Under real-world circumstances, the need to provide effective therapeutic interventions to patients who do not have an optimal response to clozapine has been cited as the most common reason for simultaneously prescribing a second antipsychotic drug in combination treatment strategies. In a clinical area where the pressing need of providing therapeutic answers has progressively increased the occurrence of antipsychotic polypharmacy, despite the lack of robust evidence of its efficacy, we sought to implement a pre-planned protocol where two alternative therapeutic answers are systematically provided and evaluated within the context of a pragmatic, multicentre, independent randomised study.

METHODS/DESIGN

The principal clinical question to be answered by the present project is the relative efficacy and tolerability of combination treatment with clozapine plus aripiprazole compared with combination treatment with clozapine plus haloperidol in patients with an incomplete response to treatment with clozapine over an appropriate period of time. This project is a prospective, multicentre, randomized, parallel-group, superiority trial that follow patients over a period of 12 months. Withdrawal from allocated treatment within 3 months is the primary outcome.

DISCUSSION

The implementation of the protocol presented here shows that it is possible to create a network of community psychiatric services that accept the idea of using their everyday clinical practice to produce randomised knowledge. The employed pragmatic attitude allowed to randomly allocate more than 100 individuals, which means that this study is the largest antipsychotic combination trial conducted so far in Western countries. We expect that the current project, by generating evidence on whether it is clinically useful to combine clozapine with aripiprazole rather than with haloperidol, provides physicians with a solid evidence base to be directly applied in the routine care of patients with schizophrenia.

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.

The efficacy of lamotrigine in clozapine-resistant schizophrenia: a systematic review and meta-analysis

BACKGROUND

Clozapine is the drug of choice for patients with unsatisfactory response to routine antipsychotic treatment. Polypharmacy is widely used among patients having clozapine-resistant schizophrenia, although no solid evidence exists for any effective augmentation therapy for this patient population. We aimed to study the efficacy of lamotrigine in the treatment of clozapine-resistant schizophrenia.

METHOD

We conducted electronic searches of the Cochrane PsiTri database, the Website of metaRegister of Controlled Trials, including NIH ClinicalTrials.gov, and a clinical trial register by the manufacturer of lamotrigine (GlaxoSmithKline). All randomized placebo-controlled studies on patients receiving clozapine were included in the analysis. The primary outcome measure was a total score for symptoms of psychosis, and the secondary outcome measures were scores for positive and negative symptoms of psychosis. For continuous and binary data, standardized mean differences (SMD), and odds ratios (OR) and the number needed to treat (NNT) were calculated, respectively.

RESULTS

Five trials with 10 to 24 weeks duration and total of 161 randomized clozapine patients were included in the meta-analysis. Lamotrigine was superior to placebo augmentation in both the primary outcome measure (SMD 0.57, 95%CI 0.25-0.89, p<0.001; OR 0.19, 95%CI 0.09-0.43, p<0.001; NNT 4, 95%CI 3-6) and secondary outcome measures (SMD 0.34, 95%CI 0.02-0.65 for positive symptoms, SMD 0.43, 95%CI 0.11-0.75 for negative symptoms).

CONCLUSIONS

This meta-analysis suggests that lamotrigine augmentation may be an effective treatment for patients with clozapine-resistant schizophrenia. A substantial proportion of these most severely ill patients appeared to obtain clinically meaningful benefit from this combination treatment.

Antipsychotic combinations vs monotherapy in schizophrenia: a meta-analysis of randomized controlled trials

CONTEXT

Despite lacking evidence for its safety and efficacy, antipsychotic cotreatment is common in schizophrenia.

OBJECTIVE

To evaluate therapeutic and adverse effects of antipsychotic cotreatment vs monotherapy in schizophrenia.

DATA SOURCES

Cochrane Schizophrenia Group register and hand searches of relevant journals/conference proceedings.

STUDY SELECTION

Randomized controlled trials comparing antipsychotic monotherapy to cotreatment with a second antipsychotic.

DATA EXTRACTION AND ANALYSIS

Two authors independently extracted data. For homogenous dichotomous data, we calculated random effects, relative risk (RR), 95% confidence intervals (CIs), and numbers needed to treat (NNT). For continuous data, weighted mean differences were calculated.

RESULTS

In 19 studies (1229 patients) with 28 monotherapy and 19 cotreatment arms, antipsychotic cotreatment was superior to monotherapy regarding 2 a priori defined coprimary outcomes: less study-specific defined inefficacy (N = 22, n = 1202, RR = 0.76, CI = 0.63-0.90, P = .002, NNT = 7, CI = 4-17, P = .0008, I(2) = 78.9%) and all-cause discontinuation (N = 20, n = 1052, RR = 0.65, CI = 0.54-0.78, P < .00001). Results were consistent using Clinical Global Impressions thresholds of less than much (P = .006) and less than minimally (P = .01) improved. Specific psychopathology and adverse event data were insufficient to yield meaningful results. In sensitivity analyses, 5 efficacy moderators emerged: concurrent polypharmacy initiation, clozapine combinations, trial duration >10 weeks, Chinese trials, and second-generation + first-generation antipsychotics. In a meta-regression, similar dose combinations, second-generation + first-generation antipsychotics and concurrent polypharmacy initiation remained significant.

CONCLUSIONS

In certain clinical situations, antipsychotic cotreatment may be superior to monotherapy. However, the database is subject to possible publication bias and too heterogeneous to derive firm clinical recommendations, underscoring the need for future research.

Does the addition of a second antipsychotic drug improve clozapine treatment?

In patients with schizophrenia who do not have an optimal response to clozapine, it remains unclear if there is an evidence base to support a second antipsychotic in combination with clozapine. The present systematic review was therefore carried out to determine the efficacy of various clozapine combination strategies with antipsychotics. Relevant studies were located by searching the Cochrane Schizophrenia Group Trials Register, Medline, and Embase (up to November 2007). Only studies randomly allocating patients to clozapine plus another antipsychotic vs clozapine monotherapy were included. The search yielded 21 studies suitable for reanalysis. In 3 trials, clozapine was combined with a phenothiazine, in 8 trials with a benzamide, and in the remaining trials with risperidone. While the majority of randomized trials were not double blind, 6 studies were double-blind placebo-controlled trials. A total of 14 randomized open studies significantly favored clozapine combination strategy in terms of mean difference (random effect standardized mean difference [SMD] = -0.80, 95% confidence interval [CI] = -1.14 to -0.46); however, data extracted from 6 randomized double-blind studies did not show a statistically significant positive effect of this combination strategy in terms of mean difference (SMD = -0.12, 95% CI = -0.57 to 0.32). In terms of percentage of patients failing to show an improvement, a total of 10 randomized open studies significantly favored clozapine combination strategy (random effect relative risk [RR] = 0.64, 95% CI = 0.42 to 0.97), but data extracted from 6 randomized double-blind studies did not show a statistically significant positive effect of this combination strategy (RR = 0.91, 95% CI = 0.75 to 1.11). We conclude that the evidence base supporting a second antipsychotic in addition to clozapine in partially responsive patients with schizophrenia is weak. This weak evidence indicates modest to absent benefit.

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.