Commentary on strategies for switching antipsychotics

Switching antipsychotics versus continued current treatment in people with non-responsive schizophrenia

BACKGROUND

Many people with schizophrenia do not respond to an initially prescribed antipsychotic drug. In such cases, one treatment strategy could be to switch to a different antipsychotic drug.

OBJECTIVES

To examine the effects of switching antipsychotic drugs in treating people with schizophrenia who have not responded to initial antipsychotic treatment.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group Trials Register (to December 2022). We inspected the references of all included studies for further relevant trials.

SELECTION CRITERIA

We included all relevant randomised controlled trials (RCTs) comparing switching to a different antipsychotic drug rather than continuing treatment with the same antipsychotic drug for people with schizophrenia who did not respond to their initial antipsychotic treatment.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data. The primary outcomes were: clinically relevant response as defined by study authors; tolerability (participants leaving the study early due to adverse effects); and quality of life assessed by the change score in the 36-Item Short Form survey. We analysed dichotomous data using the risk ratio (RR) and its 95% confidence interval (CI). We analysed continuous data using mean differences (MD) and corresponding 95% CI. We assessed the risk of bias of the included studies and used GRADE to evaluate the certainty of evidence for the following outcomes: clinically relevant response, tolerability (leaving the study early due to adverse effects), quality of life score change, acceptability (leaving the study early for any reason), general mental state (average change in general mental state scores), duration of hospitalisation, and number of participants experiencing at least one adverse effect.

MAIN RESULTS

We included 10 RCTs with 997 participants in the review. Nine studies used a parallel design, and one used a cross-over design. Seven studies were double-blind, two were single-blind and one did not provide any detail regarding blinding. All studies included people who were non-responsive to ongoing antipsychotic treatment. The minimum duration of the ongoing antipsychotic treatment ranged from three days to two years. The length of the comparison phase varied from two weeks to six months. The studies were published between 1993 and 2022. In about half of the studies, the methods of randomisation, allocation and blinding were poorly reported. The evidence is very uncertain regarding the effect of switching antipsychotics on clinically relevant response (RR 1.25, 95% CI 0.77 to 2.03; I² = 43%; 7 studies, 693 participants), quality of life (MD -1.30, 95% CI -3.44 to 0.84; 1 study, 188 participants), Positive and Negative Syndrome Scale (PANSS) score change (MD -0.92, 95% CI -4.69 to 2.86; I² = 47%; 6 studies, 777 participants), duration of hospitalisation (in days) (MD 9.19, 95% CI -8.93 to 27.31; I² = 0%; 2 studies, 34 participants) and the number of people experiencing at least one adverse effect (RR 1.29, 95% CI 0.81 to 2.05; I² = 36%; 3 studies, 412 participants). Compared to continuing current treatment, switching antipsychotics may result in little to no difference in tolerability, defined as the number of participants leaving the study early due to adverse effects (RR 0.73, 95% CI 0.24 to 2.26; I² = 31%; 6 studies, 672 participants; low-certainty evidence) and leaving the study early for any reason (RR 0.91, 95% CI 0.71 to 1.17; I² = 0%; 6 studies, 672 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

This review synthesises currently available RCT evidence on switching antipsychotics versus continuing the same antipsychotic in individuals with schizophrenia who did not respond to their initial treatment. Overall, the evidence remains highly uncertain regarding the effects of either strategy on efficacy and safety outcomes, and no definitive recommendations can currently be made. There is an urgent need for larger, well-designed trials to identify the optimal treatment strategy for these cases.

Original research paper. Switching antipsychotics: Results of 16-month non-interventional, prospective, observational clinical research of inpatients with schizophrenia spectrum disorders

The study aims to identify prescribing and switching patterns of antipsychotics in clinical practice. A 16-month, prospective study was conducted at the Psychiatric Hospital Idrija, Slovenia. Inpatients (N = 311) with schizophrenia spectrum disorders were observed. The causes for switching antipsychotics and switching strategies were analyzed. Analyzing a total of 3954 prescriptions, the collected data confirmed that treatment strategies in this psychiatric hospital are very complex. It was found that 37 percent of inpatients had at least one switch. Moreover, switches that included three or more antipsychotics were detected. The most common causes for switching antipsychotics were adverse reactions and inefficacy or lack of efficacy. Among switching options, abrupt switch was recorded several times. As some patients are receiving several antipsychotics at the same time, it is possible that unusual switching occurs in clinical practice. It seems that the choice of switching strategy is also affected by the cause and urgency for switching an antipsychotic.

The effectiveness and safety of amisulpride in Chinese patients with schizophrenia who switch from risperidone or olanzapine: a subgroup analysis of the ESCAPE study

INTRODUCTION

Second-generation antipsychotics show significant interpatient variability in treatment response and side-effect profiles, and the majority of patients with schizophrenia require multiple treatment changes. This subgroup analysis of the ESCAPE study evaluated the efficacy and safety of amisulpride in Chinese patients with schizophrenia who switched from risperidone or olanzapine.

METHODS

ESCAPE was a prospective, open-label, multicenter, single-arm Phase IV study in which Chinese patients with an ICD-10 diagnosis of schizophrenia received amisulpride for 8 weeks. This analysis included 109 patients who switched to amisulpride from risperidone (n=68) or olanzapine (n=41) and 59 treatment-naïve patients for reference. The primary effectiveness outcome was a ≥50% decrease in Positive and Negative Syndrome Scale (PANSS) Total score from Baseline to Week 8. The study was registered at ClinicalTrials.gov (NCT01795183).

RESULTS

Of the patients who switched from risperidone and olanzapine, 77.9% and 56.1% achieved ≥50% reduction in PANSS Total score from Baseline to Week 8 and 57.4% and 46.3% achieved ≥20% reduction in PANSS score from Baseline to Week 2, respectively; these end points were achieved by 66.1% and 61.0% of treatment-naïve patients, respectively. No unexpected adverse events (AEs) were reported. Of the most common AEs, extrapyramidal side effects occurred in 32.4% and 14.6%, blood prolactin increase in 32.4% and 39.0%, and ≥7% increase in body weight in 4.4% and 12% of patients switching from risperidone and olanzapine, respectively.

CONCLUSION

The results of this subgroup analysis suggest that switching to amisulpride from risperidone and olanzapine is effective and generally well tolerated in Chinese patients with schizophrenia.

Long-term impacts of adolescent risperidone treatment on behavioral responsiveness to olanzapine and clozapine in adulthood

This preclinical study investigated how a short-term risperidone treatment in adolescence impacts antipsychotic response to olanzapine and clozapine in adulthood. Antipsychotic effect was indexed by a drug's suppressive effect on avoidance responding in a rat conditioned avoidance response (CAR) model. Male adolescent Sprague-Dawley rats were first treated with risperidone (1.0mg/kg, sc) or sterile water and tested in the CAR model for 5 consecutive days from postnatal days P 40 to 44. After they became adults (~P 80-84), they were switched to olanzapine (0.5mg/kg, sc), clozapine (5.0mg/kg, sc) or vehicle treatment and tested for avoidance for 5days. During the adolescent period, repeated risperidone treatment produced a persistent inhibition of avoidance response. Throughout the 5days of adulthood drug testing, rats previously treated with risperidone in adolescence made significantly fewer avoidance responses than the vehicle ones when they all were switched to olanzapine, indicating a risperidone-induced enhancement of behavioral sensitivity to olanzapine. In contrast, when switched to clozapine, rats previously treated with risperidone made significantly more avoidance responses than the vehicle rats, indicating a risperidone-induced decrease of behavioral sensitivity to clozapine. Performance in the prepulse inhibition of acoustic startle response in adulthood was not altered by adolescent risperidone treatment. Collectively, adolescent risperidone exposure induced a long-term change in behavioral sensitivity to other atypical antipsychotic drugs, with the specific direction of change (i.e., increase or decrease) dependent on the drug to be switched to. These long-lasting changes are likely mediated by drug-induced neuroplastic changes and may also have significant clinical implications for antipsychotic treatment of chronic patients with an early onset of psychotic symptoms.

Withdrawal symptoms and rebound syndromes associated with switching and discontinuing atypical antipsychotics: theoretical background and practical recommendations

With the widespread use of atypical or second-generation antipsychotics, switching treatment has become current practice and more complicated, as the pharmacological profiles of these agents differ substantially despite their similarity in being 'atypical'. All share the ability to block dopamine D₂ receptors, and most of them also block serotonin 5-HT2A receptors. Apart from these common features, some atypical antipsychotics are also able to block or stimulate other dopamine or serotonin receptors, as well as histaminergic, muscarinergic or adrenergic receptors. As a result of the varying receptor affinities, in switching or discontinuing compounds several possible pitfalls have to be considered, including the occurrence of withdrawal and rebound syndromes. This article reviews the pharmacological background of functional blockade or stimulation of receptors of interest in regard to atypical antipsychotics and the implicated potential withdrawal and rebound phenomena. A MEDLINE search was carried out to identify information on withdrawal or rebound syndromes occurring after discontinuation of atypical antipsychotics. Using the resulting literature, we first discuss the theoretical background to the functional consequences of atypical antipsychotic-induced blockade or stimulation of neurotransmitter receptors and, secondly, we highlight the clinical consequences of this. We then review the available clinical literature on switching between atypical antipsychotics, with respect to the occurrence of withdrawal or rebound symptoms. Finally, we offer practical recommendations based on the reviewed findings. The systematic evaluation of withdrawal or rebound phenomena using randomized controlled trials is still understudied. Knowledge of pharmacological receptor-binding profiles may help clinicians in choosing adequate switching or discontinuation strategies for each agent. Results from large switching trials indicate that switching atypical antipsychotics can be performed in a safe manner. Treatment-emergent adverse events during or after switching are not always considered to be, at least in part, associated with the pre-switch antipsychotic. Further studies are needed to substantiate the evidence gained so far on different switching strategies. The use of concomitant medication, e.g., benzodiazepines or anticholinergic drugs, may help to minimize symptoms arising from the discontinuation or switching of antipsychotic treatment.

Switching patients with stable schizophrenia or schizoaffective disorder from olanzapine to risperidone long-acting injectable

BACKGROUND

Patients with schizophrenia or related disorders often switch antipsychotic therapy, most commonly due to lack of efficacy and side effects. The differences in anticipated efficacy and tolerability among atypical antipsychotics may drive switching behaviours. Switching to long-acting antipsychotics may improve adherence. Improving adherence is essential as relatively short medication gaps significantly increase the risk of schizophrenia hospitalizations. Long-term treatment with risperidone long-acting injectable (RLAI), the first available long-acting atypical antipsychotic, versus oral atypical antipsychotics showed better adherence with RLAI. Stable patients with schizophrenia or related disorders treated with a stable dose of antipsychotic showed improved efficacy when switched to flexible doses of RLAI. The most common reason for patients to switch from olanzapine to another antipsychotic is excessive weight gain. Metabolic dysfunction also occurs more commonly with olanzapine than with risperidone. Patients switching from olanzapine to risperidone experienced significant decreases in body weight, body mass index and triglyceride levels, whereas patients switching from risperidone to olanzapine experienced significant increases in body weight and triglyceride levels. The efficacy, tolerability and safety of RLAI in non-acute patients with schizophrenia or schizoaffective disorder previously treated with oral olanzapine needs to be explored.

OBJECTIVE

The objective of this study was to evaluate the efficacy, tolerability and safety of switching from oral olanzapine to RLAI.

METHODS

This was a six-month, prospective, multicentre, non-randomized, single-arm, open-label trial. The trial evaluated non-acute adult patients with psychotic disorders treated with a stable olanzapine dose who required a treatment change. Three weeks after RLAI initiation, olanzapine was tapered off over 1 week or 3 weeks. Efficacy and safety measures included the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression-Severity (CGI-S), Global Assessment of Functioning (GAF) and treatment-emergent adverse events (TEAEs).

RESULTS

Among 96 patients analysed, significant endpoint efficacy changes versus baseline were observed for PANSS, CGI-S and GAF (all p<0.0001). PANSS total score improvement was ≥20% for 65.6% of patients and ≥50% for 31.3%. TEAEs were similar in the 1- and 3-week taper groups (40.0% and 46.5%, respectively). TEAEs were generally mild (34.5%) or moderate (49.0%) in intensity.

CONCLUSION

Switching non-acute patients with schizophrenia or schizoaffective disorder requiring a treatment change from a stable dose of oral olanzapine to RLAI improved psychiatric symptom control, functioning and patient treatment satisfaction. RLAI was generally well tolerated.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT00216632.

Efficacy and tolerability of switching to ziprasidone from olanzapine, risperidone or haloperidol: an international, multicenter study

To compare the effectiveness of a switch from haloperidol (N=99), olanzapine (N=82), or risperidone (N=104) to 12 weeks of treatment with 80-160 mg/day ziprasidone in patients with stable schizophrenia or schizoaffective disorder. Stable outpatients with persistent symptoms or troublesome side effects were switched using one of three 1-week taper/switch strategies as determined by the investigator. Efficacy was assessed using the Brief Psychiatric Rating Scale score, Clinical Global Impression, Positive and Negative Symptom Scale, Montgomery-Asberg Depression Rating Scale, and the Global Assessment of Functioning Scale, and tolerability by using standard measures of weight change, extrapyramidal symptoms, and laboratory findings. Suboptimal efficacy was the primary reason for switching. The preferred switch strategy was immediate discontinuation, and the preferred dosing regimen was 120 mg/day. Completer rates were 68, 60, and 86% in the haloperidol, risperidone, and olanzapine pre-switch groups, respectively. At week 12, a switch to ziprasidone resulted in statistically significant improvement from baseline on the Brief Psychiatric Rating Scale score, Clinical Global Impression-Improvement, Positive and Negative Symptom Scale, and Global Assessment of Functioning scales, reduction in extrapyramidal symptoms and a neutral impact on metabolic parameters. Switch from olanzapine and risperidone resulted in weight reduction and from haloperidol in some weight increase. In conclusion, oral ziprasidone of 80-160 mg/day with food was a clinically valuable treatment option for stable patients with schizophrenia or schizoaffective disorder experiencing suboptimal efficacy or poor tolerability with haloperidol, olanzapine, or risperidone.