The possibility that requiring high-dose olanzapine cannot be explained by pharmacokinetics in the treatment of acute-phase schizophrenia

Call for "High-Dose" Olanzapine Research in Treatment-Resistant Psychosis

Psychiatric care has entered a new era in which care for treatment-resistant psychiatric disorder has attained priority status. Addressing treatment resistance involves 1) alleviating symptoms and signs of the diagnostic condition, 2) returning the patient to functional capacity, and 3) preventing subsequent recurrence. This approach has achieved considerable momentum in regard to major depressive disorder, as evidenced by early recognition and timely treatment, medication augmentation strategies, mind-body training for the populace at large, effective and efficient psychotherapies, and new biomedical interventions. This report proposes a pharmacotherapy that may qualify for treatment-resistant psychosis, that is, high-dose olanzapine. Considerable thought, planning, resources, and effort would be necessary to test this intervention. This proposal includes suggestions for developing an affordable means of assessing this and future candidates for treatment-resistant psychosis.

Switching and augmentation strategies for antipsychotic medications in acute-phase schizophrenia: latest evidence and place in therapy

In terms of effectiveness of antipsychotics in schizophrenia, discrepancy often exists between results from double-blind randomized controlled trials and observations in emergency or acute-phase clinical practice. For instance, the antipsychotic switching strategy is not always applicable in emergency or acute-phase situations, and augmentation of another antipsychotic is occasionally done instead. In this review, we discuss strategies for early nonresponse to an antipsychotic drug such as switching and augmentation from the perspective of emergency and acute-phase treatment. We searched PubMed for the latest evidence on switching and augmentation strategies of antipsychotics for an emergency or acute-phase period. For risperidone and olanzapine, there is some evidence on switching and augmentation strategies in the management of acute-phase schizophrenia. There may be responders to olanzapine alone among early nonresponders to risperidone, whereas there may be few responders to risperidone alone among early nonresponders to olanzapine. However, there is still insufficient evidence at this time for application of these findings to routine clinical practice. For other antipsychotics, there is little evidence for their augmentation in acute-phase practice. We should be wary of polypharmacy, as multiple agents are too often prescribed by clinicians when not warranted. Considering current evidence, we propose how to switch antipsychotics in the acute phase of schizophrenia in routine practice.

Comparative efficacy and safety of antipsychotics in the treatment of schizophrenia: a network meta-analysis in a Japanese population

BACKGROUND

The relative efficacy and tolerability of antipsychotics for schizophrenia are considerably well studied. This study aimed to examine whether previous findings could be replicated in a genetically distinct and homogenous group (ie, Japanese patients with schizophrenia) and whether previous findings could be extended to a broader range of antipsychotics with previously unclear relative efficacy and tolerability.

METHODS

Bayesian network meta-analysis was performed in which randomized trials comparing any of the following interventions were included: second-generation antipsychotics, haloperidol, or placebo. The primary outcomes for efficacy and acceptability were the response rate and all-cause discontinuation. The secondary outcomes included the improvement of Positive and Negative Syndrome Scale scores, discontinuation because of adverse events, and individual adverse events.

RESULTS

Eighteen relevant studies were identified (total n=3,446; aripiprazole =267, blonanserin =285, clozapine =47, clocapramine =295, haloperidol =857, mosapramine =493, olanzapine =179, paliperidone =136, perospirone =146, placebo =138, quetiapine =212, and risperidone =338; mean study duration =8.33±1.41 weeks). In primary outcomes, olanzapine and paliperidone showed efficacy than placebo, and olanzapine and paliperidone showed superior acceptability compared with placebo. There were differences in the incidences of individual adverse events (the best antipsychotic: extrapyramidal symptoms = olanzapine, hyperprolactinemia- related symptoms = quetiapine, sedation = paliperidone, and weight change = blonanserin) among antipsychotics.

CONCLUSION

Although the current analysis exclusively included Japanese patients with schizophrenia, no remarkable differences were observed in efficacy and safety compared with previous meta-analyses. Diverse hierarchies in safety outcomes also support the implication that individual risk expectations for adverse events can guide clinical decisions. However, the sample size was relatively limited. Additional efficacy and safety data are required to fully obtain a conclusive understanding.

Practical pharmacotherapy for acute schizophrenia patients

Well-organized clinical guidelines of pharmacotherapy for schizophrenia are not necessarily applicable to emergency and acute-phase situations. Thus, practical pharmacotherapy for acute schizophrenia patients should be based on data from real clinical practice and be independent of pharmaceutical companies. This study investigated the current guidelines being used to determine the initially preferred antipsychotics, durations required before an antipsychotic is viewed as being ineffective, and the strategies utilized for early non-responders that include switching, high dose, and augmentation. In patients who develop side-effects to the preferred antipsychotic drug, continued use may depend on the specific characteristics of the side-effects. For acute-phase patients, antipsychotics with high efficacy and effectiveness may be chosen based on meta-analysis findings for not only double-blinded but also rater-blinded randomized controlled trials. Many previous studies have reported being able to make an early prediction at 2 weeks regarding the later response. These predictions were supported by the findings of a recent meta-analysis of 34 studies that examined 9975 participants. In early non-responders to the initial antipsychotic, the effectiveness of the switching strategy appears to depend on the initial antipsychotic administered and the antipsychotic the patient is subsequently switched to. Furthermore, the effectiveness of the strategy between switching and augmentation might also depend on the initial antipsychotic administered. The current findings might serve as the basis for the use of dosing above the licensed range versus continuing the use of conventional dosing in non-responders, provided there is close monitoring of the side-effects. Further research is required before any modifications of routine practices are undertaken regarding the direction of new potential treatments.

Antipsychotic switching versus augmentation among early non-responders to risperidone or olanzapine in acute-phase schizophrenia

PURPOSE

We examined whether augmentation with olanzapine would be superior to switching to olanzapine among early non-responders (ENRs) to risperidone, and whether augmentation with risperidone would be superior to switching to risperidone among ENRs to olanzapine. We performed a rater-blinded, randomized clinical trial at psychiatric emergency sites. Eligible patients were newly admitted patients with acute schizophrenia. ENRs to the initial antipsychotic (Clinical Global Impressions-Improvement Scale: ≥ 4 at 2 weeks) were allocated to receive either augmentation with or switching to the other antipsychotic (RIS+OLZ vs. RIS-OLZ; OLZ+RIS vs.

OLZ-RIS) RESULTS

Sixty patients who completed 2 weeks of risperidone treatment were divided into 33 early responders (RIS-ER) and 27 ENRs (RIS+OLZ, n=14; RIS-OLZ, n=13). Although time to treatment discontinuation for any cause was significantly shorter in RIS+OLZ group (54.1 days [95% confidence interval, 41.3-67.0]) than in RIS-ER group (68.7 [61.2-76.2]; P=0.050), it was not significantly shorter in RIS-OLZ group (58.5 [43.1-73.9]) than in RIS-ER group (P=0.19). Sixty patients who completed 2 weeks of olanzapine treatment were divided into 36 early responders (OLZ-ER) and 24 ENRs (OLZ+RIS, n=11; OLZ-RIS, n=13). Although time to treatment discontinuation for any cause was significantly shorter in OLZ-RIS group (56.1days [40.7-71.5]) than in OLZ-ER group (74.9 [68.5-81.3]; P=0.008), it was not significantly shorter in OLZ+RIS group (64.6 [49.6-79.6]) than in OLZ-ER group (P=0.20).

CONCLUSION

Despite the lack of pharmacokinetic investigation of dose adequacy in this study, it is possible that switching to olanzapine among ENRs to risperidone might have a small advantage over augmentation with olanzapine, while augmentation with risperidone might have a small advantage over switching to risperidone among ENRs to olanzapine. Further research is required before it would be appropriate to modify routine practice in the direction of these findings.

Strategies for Early Non-response to Antipsychotic Drugs in the Treatment of Acute-phase Schizophrenia

As a strategy for antipsychotic treatment of schizophrenia, monotherapy is clearly optimal when both effective and tolerated. When a patient fails to respond to an adequate dose of an antipsychotic, alternatives include switching, administering a higher dose (above the licensed dose), polypharmacy or clozapine. Clozapine is the only option with established efficacy, but is less manageable than other antipsychotics. We therefore reviewed other options, focusing on the treatment of acute-phase schizophrenia. According to recent evidence, an antipsychotic may be viewed as ineffective within 1-4 weeks in acute-phase practice, although some differences may exist among antipsychotics. Whether a switching strategy is effective might depend on the initial antipsychotic and which antipsychotic is switched to. As weak evidence points toward augmentation being superior to continuation of the initial antipsychotic, inclusion of augmentation arms in larger studies comparing strategies for early non-responders in the acute-phase is justified. With respect to high-doses, little evidence is available regarding acute-phase treatment, and the issue remains controversial. Although evidence for antipsychotic switching, augmentation, and high-doses has gradually been accumulating, more studies performed in real clinical practice with minimal bias are required to establish strategies for early non-response to an antipsychotic drug in the treatment of acute-phase schizophrenia.