Long-Acting Injectable Second-Generation Antipsychotics vs Placebo and Their Oral Formulations in Acute Schizophrenia: A Systematic Review and Meta-Analysis of Randomized-Controlled-Trials

BACKGROUND AND HYPOTHESIS

Long-acting injectable antipsychotic drugs (LAIs) are mainly used for relapse prevention but could also be advantageous for acutely ill patients with schizophrenia.

STUDY DESIGN

We conducted a systematic review and meta-analysis of randomized-controlled-trials (RCTs) comparing the second-generation long-acting injectable antipsychotics (SGA-LAIs) olanzapine, risperidone, paliperidone, and aripiprazole with placebo or their oral counterparts in acutely ill patients with schizophrenia. We analyzed 23 efficacy and tolerability outcomes, with the primary outcome being overall symptoms of schizophrenia. The results were obtained through random effects, pairwise meta-analyses, and subgroup tests. The study quality was assessed using the Cochrane-Risk-of-Bias-Tool version-1.

STUDY RESULTS

Sixty-six studies with 16 457 participants were included in the analysis. Eleven studies compared second-generation long-acting injectable antipsychotics (SGA-LAIs) with a placebo, 54 compared second-generation oral antipsychotics (SGA-orals) with a placebo, and one compared an SGA-LAI (aripiprazole) with its oral formulation. All 4 SGA-LAIs reduced overall symptoms more than placebo, with mean standardized differences of -0.66 (95% CI: -0.90; -0.43) for olanzapine, -0.64 (-0.80; -0.48) for aripiprazole, -0.62 (-0.76; -0.48) for risperidone and -0.42 (-0.53; -0.31) for paliperidone. The side-effect profiles of the LAIs corresponded to the patterns known from the oral formulations. In subgroup tests compared to placebo, some side effects were less pronounced under LAIs than under their oral formulations.

CONCLUSIONS

SGA-LAIs effectively treat acute schizophrenia. Some side effects may be less frequent than under oral drugs, but due to the indirect nature of the comparisons, this finding must be confirmed by RCTs comparing LAIs and orals head-to-head.

Guideline for schizophrenia: implementation status and attitude toward an upcoming living guideline

The implementation status of clinical guidelines is, despite their important role in connecting research with practice, frequently not satisfactory. This study aims to investigate the implementation status of the current German guideline for schizophrenia. Moreover, the attitude toward a living guideline has been explored for the first time by presenting screenshots of the German schizophrenia guideline transferred to a digital living guideline format called MAGICapp. A cross-sectional online survey was performed under the participation of 17 hospitals for psychiatry and psychosomatic medicine in Southern Germany and one professional association for German neurologists and psychiatrists. 439 participants supplied sufficient data for analysis. 309 provided complete data sets. Regarding the current guideline for schizophrenia and key recommendations, a large awareness-to-adherence gap was found. Group comparisons between different professions (caregivers, medical doctors, psychologists/psychotherapists, psychosocial therapists) detected differences in the implementation status showing higher awareness and agreement with the schizophrenia guideline and its key recommendations among medical doctors compared to psychosocial therapists and caregivers. Moreover, we detected differences in the implementation status of the guideline as a whole and its key recommendations between specialist and assistant doctors. The attitude toward an upcoming living guideline was mostly positive, especially among younger healthcare professionals. Our findings confirm an awareness-to-adherence gap, not only for the current schizophrenia guideline in general but also for its key recommendations with apparent differences between professions. Overall, our results show promising positive attitudes toward the living guideline for schizophrenia among healthcare providers, suggesting that a living guideline may be a supportive tool in everyday clinical practice.

Conventional and living guideline for schizophrenia: barriers and facilitating factors in guideline implementation

This study aims to investigate the barriers and facilitators to guideline adherence for the print format of the German schizophrenia guideline as well as for the concept of a digital living guideline for the first time. For this purpose, the schizophrenia guideline was transferred to a digital guideline format within the web-based tool MAGICapp. An online survey was performed under participation of mental healthcare professionals (medical doctors, psychologists/psychotherapists, psychosocial therapists, caregivers) in 17 hospitals for psychiatry in Southern Germany and a professional association for German neurologists and psychiatrists. 524 participants opened the survey, 439 completed the demographic questions and commenced the content-related survey and 309 provided complete data sets. Results indicate a higher occurrence of knowledge-related barriers for the living guideline. The print version is associated with more attitude-related and external barriers. Older professionals reported more attitude-related barriers to a living guideline compared to younger professionals. Differences between professions regarding barriers were found for both formats. Various barriers exist for both guideline formats and a need for facilitators was expressed across professions. Many of the mentioned obstacles and facilitators can be more easily addressed with living guidelines. However, also living guidelines face barriers. Thus, the introduction of these new formats alone cannot lead to sustainable behavior change regarding guideline adherence. Yet, living guidelines seem to be a cornerstone to improved and tailored guideline implementation as they facilitate to keep recommendations up to date and to address the need of individual professional groups.

Antipsychotic dose, dopamine D2 receptor occupancy and extrapyramidal side-effects: a systematic review and dose-response meta-analysis

Antipsychotic drugs differ in their propensity to cause extrapyramidal side-effects (EPS), but their dose-effects are unclear. Therefore, we conducted a systematic review and dose-response meta-analysis. We searched multiple electronic databases up to 20.02.2023 for fixed-dose studies investigating 16 second-generation antipsychotics and haloperidol (all formulations and administration routes) in adults with acute exacerbations of schizophrenia. The primary outcome was the number of participants receiving antiparkinsonian medication, and if not available, the number of participants with extrapyramidal side-effects (EPS) and the mean scores of EPS rating scales were used as proxies. The effect-size was odds ratio (ORs) compared with placebo. One-stage random-effects dose-response meta-analyses with restricted cubic splines were conducted to estimate the dose-response curves. We also examined the relationship between dopamine D2 receptor (D2R) occupancy and ORs by estimating occupancies from administrated doses. We included data from 110 studies with 382 dose arms (37193 participants). Most studies were short-term with median duration of 6 weeks (range 3-26 weeks). Almost all antipsychotics were associated with dose-dependent EPS with varied degrees and the maximum ORs ranged from OR = 1.57 95%CI [0.97, 2.56] for aripiprazole to OR = 7.56 95%CI [3.16, 18.08] for haloperidol at 30 mg/d. Exceptions were quetiapine and sertindole with negligible risks across all doses. There was very low quality of findings for cariprazine, iloperidone, and zotepine, and no data for clozapine. The D2R occupancy curves showed that the risk increased substantially when D2R occupancy exceeded 75-85%, except for D2R partial agonists that had smaller ORs albeit high D2R occupancies. In conclusion, we found that the risk of EPS increases with rising doses and differs substantially in magnitude among antipsychotics, yet exceptions were quetiapine and sertindole with negligible risks. Our data provided additional insights into the current D2R therapeutic window for EPS.

A network meta-analysis of efficacy, acceptability, and tolerability of antipsychotics in treatment-resistant schizophrenia

OBJECTIVE

Clozapine is considered as the standard treatment for this subgroup, but the evidence is not unequivocal. There are several potential alternatives being used because of the possible adverse effects of clozapine. We aimed to examine the efficacy and adverse events of different antipsychotics in treatment-resistant schizophrenia by performing a network meta-analysis.

METHODS

We searched the Cochrane Schizophrenia Group register for randomized-controlled trials (up to March 06, 2022) and MEDLINE (up to January 20, 2023). We included blinded and open studies and participants with a broad definition of treatment resistance. The primary outcome was overall symptoms of schizophrenia; secondary outcomes were response to treatment, positive and negative symptoms of schizophrenia, discontinuation, side effects, quality of life, and functioning. The study was registered in Open Science Framework ( https://osf.io/9nf2y/ ).

RESULTS

We included 60 studies involving 6838 participants in the network meta-analysis. In the primary outcome, clozapine and olanzapine were more efficacious than risperidone, haloperidol, fluphenazine, sertindole, chlorpromazine, and quetiapine (range of mean SMDs, - 0.11 to - 0.48). The difference between clozapine and olanzapine was trivial and uncertain (SMD - 0.05, 95% CI, - 0.21 to 0.11). The result of other efficacy outcomes as well as subgroup and sensitivity analyses were consistent with the primary analysis. Clozapine and olanzapine were associated with more weight gain, and clozapine was associated with more sedation events compared to many other antipsychotics.

CONCLUSIONS

Clozapine remains the gold standard for patients with treatment-resistant schizophrenia. Olanzapine seems to be second-best and could be tried before switching to clozapine.

Antipsychotic-induced akathisia in adults with acute schizophrenia: A systematic review and dose-response meta-analysis

Antipsychotic-induced akathisia is severely distressing. We aimed to investigate relationships between antipsychotic doses and akathisia risk. We searched for randomised controlled trials that investigated monotherapy of 17 antipsychotics in adults with acute schizophrenia until 06 March 2022. The primary outcome was the number of participants with akathisia, which was analysed with odds ratios (ORs). We applied one-stage random-effects dose-response meta-analyses using restricted cubic splines to model the dose-response relationships. We included 98 studies (343 dose arms, 34,225 participants), most of which were short-term and had low-to-moderate risk of bias. We obtained data on all antipsychotics except clozapine and zotepine. In patients with acute exacerbations of chronic schizophrenia, from moderate to high certainty of evidence, our analysis showed that sertindole and quetiapine carried negligible risks for akathisia across examined doses (flat curves), while most of the other antipsychotics had their risks increase initially with increasing doses and then either plateaued (hyperbolic curves) or continued to rise (monotonic curves), with maximum ORs ranging from 1.76 with 95% Confidence Intervals [1.24, 2.52] for risperidone at 5.4 mg/day to OR 11.92 [5.18, 27.43] for lurasidone at 240 mg/day. We found limited or no data on akathisia risk in patients with predominant negative symptoms, first-episode schizophrenia, or elderly patients. In conclusion, liability of akathisia varies between antipsychotics and is dose-related. The dose-response curves for akathisia in most antipsychotics are either monotonic or hyperbolic, indicating that higher doses carry a greater or equal risk compared to lower doses.

Long-term efficacy of antipsychotic drugs in initially acutely ill adults with schizophrenia: systematic review and network meta-analysis

Most acute phase antipsychotic drug trials in schizophrenia last only a few weeks, but patients must usually take these drugs much longer. We examined the long-term efficacy of antipsychotic drugs in acutely ill patients using network meta-analysis. We searched the Cochrane Schizophrenia Group register up to March 6, 2022 for randomized, blinded trials of at least 6-month duration on all second-generation and 18 first-generation antipsychotics. The primary outcome was change in overall symptoms of schizophrenia; secondary outcomes were all-cause discontinuation; change in positive, negative and depressive symptoms; quality of life, social functioning, weight gain, antiparkinson medication use, akathisia, serum prolactin level, QTc prolongation, and sedation. Confidence in the results was assessed by the CINeMA (Confidence in Network Meta-Analysis) framework. We included 45 studies with 11,238 participants. In terms of overall symptoms, olanzapine was on average more efficacious than ziprasidone (standardized mean difference, SMD=0.37, 95% CI: 0.26-0.49), asenapine (SMD=0.33, 95% CI: 0.21-0.45), iloperidone (SMD=0.32, 95% CI: 0.15-0.49), paliperidone (SMD=0.28, 95% CI: 0.11-0.44), haloperidol (SMD=0.27, 95% CI: 0.14-0.39), quetiapine (SMD=0.25, 95% CI: 0.12-0.38), aripiprazole (SMD=0.16, 95% CI: 0.04-0.28) and risperidone (SMD=0.12, 95% CI: 0.03-0.21). The 95% CIs for olanzapine versus aripiprazole and risperidone included the possibility of trivial effects. The differences between olanzapine and lurasidone, amisulpride, perphenazine, clozapine and zotepine were either small or uncertain. These results were robust in sensitivity analyses and in line with other efficacy outcomes and all-cause discontinuation. Concerning weight gain, the impact of olanzapine was higher than all other antipsychotics, with a mean difference ranging from -4.58 kg (95% CI: -5.33 to -3.83) compared to ziprasidone to -2.30 kg (95% CI: -3.35 to -1.25) compared to amisulpride. Our data suggest that olanzapine is more efficacious than a number of other antipsychotic drugs in the longer term, but its efficacy must be weighed against its side effect profile.

Metabolic side effects in persons with schizophrenia during mid- to long-term treatment with antipsychotics: a network meta-analysis of randomized controlled trials

Metabolic side effects of antipsychotic drugs can have serious health consequences and may increase mortality. Although persons with schizophrenia often take these drugs for a long time, their mid- to long-term metabolic effects have been studied little so far. This study aimed to evaluate the mid- to long-term metabolic side effects of 31 antipsychotics in persons with schizophrenia by applying a random-effects Bayesian network meta-analysis. We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (up to April 27, 2020) and PubMed (up to June 14, 2021). We included published and unpublished, open and blinded randomized controlled trials with a study duration >13 weeks which compared any antipsychotic in any form of administration with another antipsychotic or with placebo in participants diagnosed with schizophrenia. The primary outcome was weight gain measured in kilograms. Secondary outcomes included "number of participants with weight gain", fasting glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. We identified 137 eligible trials (with 35,007 participants) on 31 antipsychotics, with a median follow-up of 45 weeks. Chlorpromazine produced the most weight gain (mean difference to placebo: 5.13 kg, 95% credible interval, CrI: 1.98 to 8.30), followed by clozapine (4.21 kg, 95% CrI: 3.03 to 5.42), olanzapine (3.82 kg, 95% CrI: 3.15 to 4.50), and zotepine (3.87 kg, 95% CrI: 2.14 to 5.58). The findings did not substantially change in sensitivity and network meta-regression analyses, although enriched design, drug company sponsorship, and the use of observed case instead of intention-to-treat data modified the mean difference in weight gain to some extent. Antipsychotics with more weight gain were often also among the drugs with worse outcome in fasting glucose and lipid parameters. The confidence in the evidence ranged from low to moderate. In conclusion, antipsychotic drugs differ in their propensity to induce metabolic side effects in mid- to long-term treatment. Given that schizophrenia is often a chronic disorder, these findings should be given more consideration than short-term data in drug choice.