Exploring the long-term safety of asenapine in adults with schizophrenia in a double-blind, fixed-dose, extension study

A review on side effect management of second-generation antipsychotics to treat schizophrenia: a drug safety perspective

INTRODUCTION

Effective side effects management present a challenge in antipsychotic treatment with second-generation antipsychotics (SGAs). In recent years, most of the commonly used SGAs, except for clozapine, have been shown to differ only slightly in their effectiveness, but considerably regarding perceived side effects, safety profiles, and compatibility to preexisting medical conditions.

AREAS COVERED

The current state of available evidence on side-effect management in SGA treatment of patients with schizophrenia spectrum disorders (SSD) is reviewed. In addition, current guideline recommendations are summarized, highlighting evidence gaps.

EXPERT OPINION

SGA safety and side effects needs to be considered in treatment planning. Shared decision-making assistants (SDMA) can support patients, practitioners and relatives to orient their decisions toward avoiding side effects relevant to patients' adherence. Alongside general measures like psychosocial and psychotherapeutic care, switching to better tolerated SGAs can be considered a relatively safe strategy. By contrast, novel meta-analytical evidence emphasizes that dose reduction of SGAs can statistically increase the risk of relapse and other unfavorable outcomes. Further, depending on the type and severity of SGA-related side effects, specific treatments can be used to alleviate induced side effects (e.g. add-on metformin to reduce weight-gain). Finally, discontinuation should be reserved for acute emergencies.

Antipsychotic dose reduction compared to dose continuation for people with schizophrenia

BACKGROUND

Antipsychotic drugs are the mainstay treatment for schizophrenia, yet they are associated with diverse and potentially dose-related side effects which can reduce quality of life. For this reason, the lowest possible doses of antipsychotics are generally recommended, but higher doses are often used in clinical practice. It is still unclear if and how antipsychotic doses could be reduced safely in order to minimise the adverse-effect burden without increasing the risk of relapse.

OBJECTIVES

To assess the efficacy and safety of reducing antipsychotic dose compared to continuing the current dose for people with schizophrenia.

SEARCH METHODS

We conducted a systematic search on 10 February 2021 at the Cochrane Schizophrenia Group's Study-Based Register of Trials, which is based on CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, PubMed, ClinicalTrials.gov, ISRCTN, and WHO ICTRP. We also inspected the reference lists of included studies and previous reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any dose reduction against continuation in people with schizophrenia or related disorders who were stabilised on their current antipsychotic treatment.  DATA COLLECTION AND ANALYSIS: At least two review authors independently screened relevant records for inclusion, extracted data from eligible studies, and assessed the risk of bias using RoB 2. We contacted study authors for missing data and additional information. Our primary outcomes were clinically important change in quality of life,  rehospitalisations and dropouts due to adverse effects; key secondary outcomes were clinically important change in functioning, relapse, dropouts for any reason, and at least one adverse effect. We also examined scales measuring symptoms, quality of life, and functioning as well as a comprehensive list of specific adverse effects. We pooled outcomes at the endpoint preferably closest to one year. We evaluated the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 25 RCTs, of which 22 studies provided data with 2635 participants (average age 38.4 years old). The median study sample size was 60 participants (ranging from 18 to 466 participants) and length was 37 weeks (ranging from 12 weeks to 2 years). There were variations in the dose reduction strategies in terms of speed of reduction (i.e. gradual in about half of the studies (within 2 to 16 weeks) and abrupt in the other half), and in terms of degree of reduction (i.e. median planned reduction of 66% of the dose up to complete withdrawal in three studies). We assessed risk of bias across outcomes predominantly as some concerns or high risk.  No study reported data on the number of participants with a clinically important change in quality of life or functioning, and only eight studies reported continuous data on scales measuring quality of life or functioning. There was no difference between dose reduction and continuation on scales measuring quality of life (standardised mean difference (SMD) -0.01, 95% confidence interval (CI) -0.17 to 0.15, 6 RCTs, n = 719, I2 = 0%, moderate certainty evidence) and scales measuring functioning (SMD 0.03, 95% CI -0.10 to 0.17, 6 RCTs, n = 966, I2 = 0%, high certainty evidence). Dose reduction in comparison to continuation may increase the risk of rehospitalisation based on data from eight studies with estimable effect sizes; however, the 95% CI does not exclude the possibility of no difference (risk ratio (RR) 1.53, 95% CI 0.84 to 2.81, 8 RCTs, n = 1413, I2 = 59% (moderate heterogeneity), very low certainty evidence). Similarly, dose reduction increased the risk of relapse based on data from 20 studies (RR 2.16, 95% CI 1.52 to 3.06, 20 RCTs, n = 2481, I2 = 70% (substantial heterogeneity), low certainty evidence).   More participants in the dose reduction group in comparison to the continuation group left the study early due to adverse effects (RR 2.20, 95% CI 1.39 to 3.49, 6 RCTs with estimable effect sizes, n = 1079, I2 = 0%, moderate certainty evidence) and for any reason (RR 1.38, 95% CI 1.05 to 1.81, 12 RCTs, n = 1551, I2 = 48% (moderate heterogeneity), moderate certainty evidence). Lastly, there was no difference between the dose reduction and continuation groups in the number of participants with at least one adverse effect based on data from four studies with estimable effect sizes (RR 1.03, 95% CI 0.94 to 1.12, 5 RCTs, n = 998 (4 RCTs, n = 980 with estimable effect sizes), I2 = 0%, moderate certainty evidence).  AUTHORS' CONCLUSIONS: This review synthesised the latest evidence on the reduction of antipsychotic doses for stable individuals with schizophrenia. There was no difference between dose reduction and continuation groups in quality of life, functioning, and number of participants with at least one adverse effect. However, there was a higher risk for relapse and dropouts, and potentially for rehospitalisations, with dose reduction. Of note, the majority of the trials focused on relapse prevention rather potential beneficial outcomes on quality of life, functioning, and adverse effects, and in some studies there was rapid and substantial reduction of doses. Further well-designed RCTs are therefore needed to provide more definitive answers.

Standard versus reduced dose of antipsychotics for relapse prevention in multi-episode schizophrenia: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Dose reduction of antipsychotic maintenance treatment in individuals with schizophrenia could be desirable to minimise adverse effects, but evidence for this strategy is unclear. We aimed to compare risks and benefits of reduced versus standard doses of antipsychotics.

METHODS

We searched Embase, Medline, PsycINFO, and the Cochrane Library from database inception until June 17, 2020, for randomised trials in adults with schizophrenia or schizoaffective disorder lasting at least 24 weeks, including individuals clinically stable at baseline, and comparing at least two doses of the same antipsychotic, excluding trials in first-episode psychosis or treatment-resistant schizophrenia. We compared low-dose (within 50-99% of the lower limit of the standard dose) and very-low dose (less than 50% of the lower limit) with standard dose, defined as doses higher than the lower limit of the treatment dose recommended by the International Consensus Study. Data from published reports on number of participants, treatment, sex, age, number of events, and changes in psychopathology scores were extracted independently by at least two authors. Investigators or sponsors were contacted by email to obtain missing information regarding outcomes. Co-primary outcomes were relapse and all-cause discontinuation. Study-level data were meta-analysed using random-effects models, calculating risk ratios (RRs) for dichotomous data, and Hedges' g for continuous data. The protocol was registered with OSF registries.

FINDINGS

7853 references were identified in the database search and one additional reference from a manual review of relevant studies. 5744 abstracts were assessed for eligibility, and 101 references were assessed for full-text review. Of these, 79 were excluded for a variety of reasons, resulting in 22 studies being included in the meta-analysis, reporting on 24 trials and 3282 individuals. Study participants had a median age of 38 years (IQR 36-40) with 2166 (65·9%) males and 1116 (34·0%) females. Compared with standard dose, low dose increased the risk of relapse by 44% (16 trials, 1920 participants; RR 1·44, 95% CI 1·10-1·87; p=0·0076; I²=46%) and the risk of all-cause discontinuation by 12% (16 trials, 1932 participants; RR 1·12, 1·03-1·22; p=0·0085; I²=0%). Very low dose increased the risk of relapse by 72% (13 trials, 2058 participants; RR 1·72, 95% CI 1·29-2·29; p=0·0002; I²=70%) and all-cause discontinuation by 31% (11 trials, 1866 participants; RR 1·31, 1·11-1·54; p=0·0011; I²=63%). Compared with low dose, very low dose did not significantly increase the risk of relapse (five trials, 686 participants; RR 1·31, 95% CI 0·96-1·79; p=0·092; I²=51%) or all-cause discontinuation (five trials 686 participants; RR 1·11, 95% CI 0·95-1·30; p=0·18; I²=43%). Subgroup analyses comparing double-blind versus open-label studies, first-generation versus second-generation antipsychotics, and oral versus long-acting injectable antipsychotics were consistent with the overall results. Most studies were classified as having some concerns in the risk of bias assessment, which was mainly caused by absence of publicly available study registrations.

INTERPRETATION

During maintenance treatment in multi-episode schizophrenia, antipsychotic doses should probably not be reduced below the standard dose range recommended for acute stabilisation, because reducing the dose further is associated with an increased risk of both relapse and all-cause discontinuation.

FUNDING

None.

Transdermal Asenapine in Schizophrenia: A Systematic Review

BACKGROUND

Asenapine is a novel antipsychotic that has demonstrated efficacy in controlling psychosis in schizophrenia and mania in bipolar illness. It must be administered as a sublingual formulation because it is nearly completely metabolized in the first pass through the liver. Recently, a transdermal formulation of asenapine has been approved for schizophrenia by the Food and Drug Administration.

METHODS

A systematic review of transdermal asenapine was done utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model.

DISCUSSION

There are several formulations of transdermal asenapine but only Secuado^® has been approved for clinical use. Total bioavailability is 35%. Peak plasma concentration (Cmax) is 4 ng/mL and occurs within 1 hr (Tmax); elimination half-life (t_1/2) is 24 hrs (range 13.4 to 39.2 h). Asenapine is highly bound (95%) to albumin and α₁-acid glycoprotein. It has a unique receptor profile in which it functions as an antagonist at multiple receptors with affinity that is higher than D₂ (K_i = 1.3) including D₃, D₄, 5HT_2A, 5HT_2C, 5HT_2B, 5HT₇, 5HT₆, H₁, and α2. This profile suggests that asenapine may be of particular value off label for bipolar depression, anxiety, and aggression. Transdermal asenapine was only tested in one randomized, placebo-controlled study of acute psychosis in schizophrenia. It was superior to placebo at week 6 with nearly one-third of patients experiencing >30% improvement in total PANSS score which translates in a number needed to treat (NNT) of 9.

Long-term effectiveness of oral second-generation antipsychotics in patients with schizophrenia and related disorders: a systematic review and meta-analysis of direct head-to-head comparisons

Second-generation antipsychotics (SGAs) are recommended for maintenance treatment in schizophrenia. However, comparative long-term effectiveness among SGAs is unclear. Here we provide a systematic review and meta-analysis of randomized trials lasting ≥⃒6 months comparing SGAs head-to-head in schizophrenia and related disorders. The primary outcome was all-cause discontinuation. Secondary outcomes included efficacy and tolerability, i.e., psychopathology, inefficacy-related and intolerability-related discontinuation, relapse, hospitalization, remission, functioning, quality of life, and adverse events. Pooled risk ratio and standardized mean difference were calculated using random-effects models. Across 59 studies (N=45,787), lasting 47.4±32.1 weeks (range 24-186), no consistent superiority of any SGA emerged across efficacy and tolerability outcomes. Regarding all-cause discontinuation, clozapine, olanzapine and risperidone were significantly (p<0.05) superior to several other SGAs, while quetiapine was inferior to several other SGAs. As to psychopathology, clozapine and olanzapine were superior to several other SGAs, while quetiapine and ziprasidone were inferior to several other SGAs. Data for other efficacy outcomes were sparse. Regarding intolerability-related discontinuation, risperidone was superior and clozapine was inferior to several other SGAs. Concerning weight gain, olanzapine was worse than all other compared non-clozapine SGAs, and risperidone was significantly worse than several other SGAs. As to prolactin increase, risperidone and amisulpride were significantly worse than several other SGAs. Regarding parkinsonism, olanzapine was superior to risperidone, without significant differences pertaining to akathisia. Concerning sedation and somnolence, clozapine and quetiapine were significantly worse than some other SGAs. In summary, different long-term SGA efficacy and tolerability patterns emerged. The long-term risk-benefit profiles of specific SGAs need to be tailored to individual patients to optimize maintenance treatment outcomes.

Medication-Induced Akathisia with Newly Approved Antipsychotics in Patients with a Severe Mental Illness: A Systematic Review and Meta-Analysis

BACKGROUND

Akathisia is a common and distressing movement disorder that can be associated with the use of antipsychotics. It is characterized by a subjective (inner restlessness) and an objective (excessive movements) component. Akathisia can have a negative impact on clinical outcome and even lead to treatment discontinuation. Although medication-induced akathisia is more commonly associated with the use of first-generation antipsychotics (FGAs), it also occurs with second-generation antipsychotics (SGAs), including the newly approved antipsychotics (NAPs) asenapine, lurasidone, iloperidone, cariprazine, and brexpiprazole. Until now, no meta-analysis has been published on the risk of akathisia for all NAPs, as monotherapy or adjunctive treatment, in patients with a severe mental illness.

OBJECTIVE

The primary objectives of this systematic review and meta-analysis were to (i) compare akathisia incidence rates of the NAPs, as monotherapy or adjunctive treatment, in adult patients with a severe mental illness (i.e., schizophrenia, bipolar disorder, or major depressive disorder), using data from published and unpublished randomized controlled trials; and (ii) examine the role of several study characteristics explaining differences in akathisia incidence rates between studies.

METHODS

A systematic literature search, using the PubMed, EMBASE, and Cochrane Library databases (until October 2018), was conducted for English-language placebo- as well as active-controlled clinical trials, including subjective (percentage of patients reporting akathisia) and/or scale-defined medication-induced akathisia incidence rates with NAPs (as monotherapy or as adjunctive treatment) in adult patients with schizophrenia, bipolar disorder, or major depressive disorder. Additional unpublished clinical trials were identified through the ClinicalTrials.gov electronic database. Two meta-analyses (incidence rates and odds ratio [OR] [placebo vs. active] of medication-induced akathisia with NAPs) were performed to obtain an optimal estimation of akathisia risks of adult patients with a severe mental illness under these treatment conditions and to assess the role of study characteristics.

RESULTS

Two hundred and thirteen reports were selected as potentially eligible for our meta-analysis. Of these, 48 met the inclusion criteria. Eight records, identified through the ClinicalTrials.gov database and cross-referencing, and which fulfilled the inclusion criteria, were added, resulting in a total of 56 records (iloperidone = 5, asenapine = 11, lurasidone = 15, brexpiprazole = 13, cariprazine = 12). The estimated weighted mean incidence rate of akathisia was 7.7% (95% confidence interval [CI] 6.5-9.1), with estimates being 3.9% (95% CI 2.4-6.3) for iloperidone, 6.8% (95% CI 5.1-9.0) for asenapine, 10.0% (95% CI 7.4-13.5) for brexpiprazole, 12.7% (95% CI 10.1-16.1) for lurasidone, and 17.2% (95% CI 13.4-22.1) for cariprazine. After Tukey-adjustment for multiple testing, the incidence rate of akathisia was significantly (p < 0.05) lower for iloperidone than for brexpiprazole, lurasidone, and cariprazine. In addition, the incidence rate of akathisia was significantly (p < 0.05) lower for asenapine than for lurasidone and cariprazine. Finally, the incidence rate of akathisia was significantly (p < 0.05) lower for brexpiprazole than for cariprazine. Type of medication (p < 0.0001), diagnosis (p = 0.02), and race (p = 0.0003) significantly explained part of the heterogeneity of the incidence estimates of akathisia between studies. The estimated weighted OR of akathisia under medication, compared with placebo, was 2.43 (95% CI 1.91-3.10). The OR was smallest for iloperidone (OR 1.20; 95% CI 0.42-3.45) and increased for brexpiprazole (OR 2.04; 95% CI 1.09-3.83), asenapine (OR 2.37; 95% CI 1.32-4.27), lurasidone (OR 3.74; 95% CI 2.32-6.02), and cariprazine (OR 4.35; 95% CI 2.80-6.75). Only type of medication (p = 0.03) explained systematic differences in the OR for akathisia between placebo versus active treatment across studies. After Tukey-adjustment for multiple testing, no significant differences between these ORs were found. The severity of akathisia with NAPs generally is mild to moderate, only leading to treatment discontinuation in a minority of cases (< 5%).

CONCLUSIONS

The use of a NAP raises the akathisia risk more than two-fold when compared with patients receiving placebo. Although distinctions between the different NAPs were not clear in placebo-controlled trials, the results of our meta-analyses and systematic review generally indicate that these differences more than likely reflect real differences, with iloperidone showing the most and cariprazine showing the least benign akathisia profile. Moreover, due to patient characteristics and methodological issues, incidence rates of akathisia with NAPs found in this meta-analysis may even be an underestimation of true incidence rates.

Asenapine Treatment in Pediatric Patients with Bipolar I Disorder or Schizophrenia: A Review

Asenapine, administered as a twice-daily (BID) sublingual tablet, is approved in the US as monotherapy for the acute treatment of manic and mixed episodes of bipolar I disorder in children and adolescents aged 10-17 years based on the positive results of one 3-week, double-blind, placebo-controlled study; the recommended dose is 2.5-10 mg BID. Although asenapine has been studied in pediatric patients with schizophrenia, it is not approved for this indication. Asenapine is not approved for pediatric use in bipolar I disorder or schizophrenia in other major markets. To inform clinicians treating psychiatric disorders in pediatric patients, we have summarized the neuropharmacology, pharmacokinetics, clinical trial experience, and clinical use of asenapine in pediatric patients. After rapid absorption through the oral mucosa, the pharmacokinetic profile of asenapine in pediatric patients is similar to that which is observed in adult patients, indicating that the recommended adult dosage does not need to be adjusted for pediatric use. Intake of food and water should be avoided for 10 min after administration. In clinical trials, asenapine was generally safe and well tolerated in pediatric patients with bipolar I disorder and schizophrenia. Serious adverse effects were generally related to worsening of the underlying psychiatric disorder. The most common treatment-emergent adverse events (TEAEs) in both indications were sedation and somnolence. Like some other second-generation antipsychotic agents, weight gain and changes in some metabolic parameters were noted; oral effects (e.g., oral hypoesthesia, dysgeusia, paresthesia) related to sublingual administration did not typically result in treatment discontinuation and were generally transient. Extrapyramidal symptom TEAEs occurred in ≥5% of asenapine-treated patients in the acute and long-term studies in bipolar I disorder and schizophrenia.