The safety and tolerability of cariprazine in patients with manic or mixed episodes associated with bipolar I disorder: A 16-week open-label study

Recommendation for a Therapeutic Reference Range of Cariprazine-A Short Communication

BACKGROUND

Therapeutic reference ranges are essential for therapeutic drug monitoring to evaluate results and adjust pharmacotherapy. The measured serum concentrations of cariprazine-treated patients have frequently been found to lie beyond the currently used therapeutic reference range; furthermore, reliable data for establishing evidence-based therapeutic ranges are scarce. The current therapeutic reference ranges have only been estimated; however, real-world data on cariprazine are missing. Individual serum concentrations were analyzed, and the validity of the currently used reference ranges was assessed.

METHODS

Serum concentrations of 19 psychiatric patients treated with cariprazine without pharmacokinetic abnormalities were retrospectively analyzed. Only the last measurement per patient was included in the analysis, and patients who underwent a dose adjustment in the subsequent 2 weeks after sampling were excluded (assuming that the target dose and response had been achieved at that time). Serum concentrations were compared with the therapeutic reference range (10-20 ng/mL) of the Arbeitsgemeinschaft für Neuropsychiatrie und Pharmakotherapie consensus guidelines of 2017 and with a recent recommendation for a lower therapeutic reference range (5-15 ng/mL).

RESULTS

The mean serum concentration was 9.1 ± 4.1 SD ng/mL. A total of 47.4% of the values were within the therapeutic reference range of 10-20 ng/mL, and 78.9% fell within the range of 5-15 ng/mL.

CONCLUSIONS

These results support previous recommendations for lowering the therapeutic reference range to 5-15 ng/mL. The calculated therapeutic reference range was 5.0-13.2 ng/mL. It may even be potentially lower because clinicians may have tried to titrate the dose to a serum concentration within the current therapeutic reference range of 10-20 ng/mL.

Mini Review on Cariprazine: A Promising Antipsychotic Agent

Cariprazine is a piperazine derivative approved by the USFDA in 2015 as a novel atypical antipsychotic drug (APD) to treat adults with schizophrenia and bipolar manic or mixed episodes in adults. However, due to the partial agonist action on dopamine D₂, D₃ receptors, and serotonin 5-HT_1A receptors as well as the antagonist effect on 5-HT_2A, 5-HT_2B, and H₁ receptors, cariprazine differs pharmacologically from other APDs, both typical and atypical. Moreover, cariprazine also has a unique pharmacokinetic profile due to the formation of two clinically significant metabolites: desmethyl-cariprazine (DCAR) and desmethyl-cariprazine (DDCAR). They are eliminated by CYP3A4 and also, to a lesser extent, by CYP2D6. Here, we also review the effectiveness, safety, as well as current clinical update of cariprazine in bipolar I disorder associated with/without mania and schizophrenia through randomized and post-hoc analysis. The potential benefits of cariprazine as a promising therapeutic alternative in addressing major clinical requirements for better therapy of such severe neuropsychiatric conditions were demonstrated in this summarized review study.

Risk of Drug-induced Movement Disorders with Newer Antipsychotic Agents

Background:

The last decade has seen development of numerous novel antipsychotic drugs with unique mechanisms including long-acting formulations for clinical use. A comparative assessment of these new drugs with each other and previous antipsychotics have not been performed with regards to risk for drug-induced movement disorders (DIMD).

Methods:

Medline was searched from January 2010 to February 2022 for primary research articles and review articles in English using the search terms “extrapyramidal” and “tardive” with individual drug names of novel antipsychotics.

Results:

We identified articles describing the risk of DIMD with 6 novel antipsychotics, 4 novel formulations, and 3 experimental antipsychotics. Both short- and long-term data generally showed comparable to lower risk of DIMD with novel antipsychotics and recent long-acting formulations compared to previously marketed antipsychotics.

Discussion:

Several novel antipsychotics, particularly lumateperone and pimavanserin, show promise in being able to treat psychosis while reducing the risk of DIMD. Long-acting paliperidone may reduce risk of DIMD while other long-acting injectable formulations of SGA have similar risk of DIMD compared to oral formulations. New drug targets for treating psychosis without dopamine blockade also show promise.

Cariprazine: A new partial dopamine agonist with a familiar profile

OBJECTIVE

Cariprazine is the third partial dopamine agonist now available in Australia. This paper will review the properties, evidence and likely clinical place of cariprazine.

CONCLUSION

Cariprazine is a partial agonist with high affinity at dopamine D₂ and D₃ receptors, partial agonism at 5HT_1a receptors, moderate 5HT_2a and H₁ antagonism and no anticholinergic activity. It is rapidly absorbed, is unaffected by food, achieves a peak plasma level in 4-8 hours and has high bioavailability. The half-life of cariprazine and its metabolites is long (7-8 days); steady state occurs in 4-8 weeks. It is hepatically metabolized via 3A4 cytochrome enzymes. Cariprazine is an effective antipsychotic in acute schizophrenia in both short and longer placebo-controlled studies. Cariprazine appears to have small advantages in negative symptoms of schizophrenia. While not approved for bipolar disorder, cariprazine is effective in mania and mixed states but requires doses higher than current maximums recommended. Cariprazine causes more akathisia than aripiprazole or brexpiprazole but is less prone to insomnia, weight gain and sedation. Risks for hyperprolactinaemia and QT_c prolongation are low. Cariprazine is another 'metabolically-friendly' antipsychotic for schizophrenia, with advantages for those with negative symptoms, mood symptoms or problems with adherence.

Case Report: Long-Acting Oral Cariprazine

Introduction

Cariprazine is a third-generation antipsychotic, approved for the treatment of schizophrenia and bipolar disorder and used off-label for schizoaffective disorder and treatment-resistant depression. Cariprazine is a partial agonist at dopamine receptors D2 and D3 and serotonin receptor 5HT1A and an antagonist at serotonin receptors 5HT2B and 5HT2A. It is metabolized by CYP3A4 in desmetyl-cariprazine and didesmethyl-cariprazine, both active metabolites with a half-life of 1-2 days and 2-3 weeks, respectively.

Case Report

Here we show the cases of 3 outpatients diagnosed with bipolar I disorder (two patients) and schizoaffective disorder (one patients) and characterized by low adherence to treatment, satisfactory cognitive and personal functioning and average disease severity to whom we administered cariprazine as a monotherapy, on a two-times a week schedule (i.e., every 72-96 h). We evaluated response to treatment and disease remission according to conventional definitions, using rating scales BPRS, PANSS and BDI-II. Two-times a week treatment was set either after a disease relapse (one patient), after a sustained remission obtained with daily administration of cariprazine (one patient) or since our first evaluation (one patient). After 4 weeks of treatment all three patients satisfied criteria for response to treatment and remission, a result that was sustained for 8 (in one patients) and 12 months (in other two patients) and still ongoing.

Discussion

Reported results support our hypothesis that long half-lives of cariprazine and its metabolites provide an adequate therapeutic response with a two-times a week administration. In selected patients, cariprazine administered as a "oral long-acting" seems effective in treating acute episodes of illness and in sustaining remission, combining advantages of oral and long-acting injectable antipsychotics concerning therapeutic alliance.

Real-Life Clinical Experience With Cariprazine: A Systematic Review of Case Studies

Background

The hierarchy of evidence coming from evidence-based medicine favors meta-analyses and randomized controlled trials over observational studies and clinical cases. Nonetheless, in the field of psychiatry, where conditions are much more complex, additional evidence coming from real-world clinical practice is necessary to complement data from these gold standards. Thus, in this systematic review, the aim is to summarize the evidence coming from clinical case reports regarding cariprazine, a third-generation antipsychotic drug that has been approved for the treatment of schizophrenia and bipolar I disorder with manic, depressive or mixed features in adults.

Methods

A systematic review was performed using Embase and Pubmed databases searching for English-language cases published in peer-reviewed journals between 2000 January and 2021 September with the following search terms: (cariprazin* OR "rgh-188" OR rgh188 OR vraylar OR reagila) AND ("case report*" OR "case report"/de OR "case stud*" OR "case study"/de OR "case seri*").

Results

After the removal of duplicates, 49 articles were retrieved via the search, from which 22 were suitable for this review. These 22 articles encompassed 38 cases from which 71% described patients with schizophrenia, 16% patients with psychotic disorders, 5% patients with mood disorder and 8% described patients with other disorders such as Wernicke-Korsakoff syndrome, borderline personality disorder and obsessive-compulsive disorder with paranoid schizophrenia. The median age of patients was 31, and half of them were female. The majority of patients (76%) started cariprazine with 1.5 mg/day, and the most common maintenance dose was 4.5 mg/day (34%) and 3.0 mg/day (29%).

Conclusion

Cariprazine was found to be safe and effective in a wide range of psychiatric conditions with different symptom profiles from acute psychotic symptoms through addiction to negative and cognitive symptoms. The results are in-line with the established evidence from clinical trials, however, they also show how cariprazine can be successfully utilized for treating certain symptoms irrespective of the indication.

Association between abnormal glycolipid level and cognitive dysfunction in drug-naïve patients with bipolar disorder

OBJECTIVES

Cognitive impairment and abnormal glycolipid metabolism are common clinical features of bipolar disorder (BD). The purpose of this study was to investigate the relationship between conventional glycolipid metabolism indicators and cognitive impairment in patients with BD.

METHODS

A total of 132 drug-naïve patients with BD and 129 healthy controls (HC) were recruited in the study. Five serum glycolipid metabolism indicators were measured and cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the Stroop Color-Word Test (Stroop test) for each participant.

RESULTS

The scores of immediate memory, attention, language and delayed memory in BD group were significantly lower than those in HC group (P < 0.05). The triglyceride (TG) level in BD group was higher than that in HC group (P = 0.011), and the total cholesterol and high-density lipoprotein cholesterol (HDL) levels were lower than those in HC group (P = 0.026; P = 0.001). Regression analysis showed that TG level was significantly correlated with RBANS total score (β = 0.245, P = 0.008), attention (β = 0.289, P = 0.03) and delayed memory (β = 0.221, P = 0.023). Fasting blood glucose (FBG) level was significantly correlated with language subscale score (β = -0.187, P = 0.046) in BD.

LIMITATIONS

Cross-sectional design and limited control variables.

CONCLUSIONS

Elevated FBG and TG levels may be associated with cognitive dysfunction in BD patients. Improving glycolipid metabolism in patients with BD may help to improve certain domain-specific cognitive functions.

Minimal Effects of Cariprazine on Prolactin Levels in Bipolar Disorder and Schizophrenia

BACKGROUND

Many medications used to treat schizophrenia and bipolar I disorder are linked to hyperprolactinemia. The effects of cariprazine, a dopamine D₃/D₂ receptor partial agonist, on prolactin levels in patients with schizophrenia or bipolar I disorder were evaluated.

METHODS

Effects on prolactin were evaluated using pooled data from randomized, double-blind, placebo-controlled studies in patients with schizophrenia (4 studies; 6-week duration; cariprazine 1.5-3 mg/d, 4.5-6 mg/d, and 9-12 mg/d), bipolar mania (3 studies; 3-week duration; cariprazine 3-6 and 9-12 mg/d), and bipolar depression (3 studies; 6- to 8-week duration; cariprazine 1.5 and 3 mg/d). Long-term effects were analyzed using open-label studies in patients with schizophrenia (2 studies; 48-week duration) and patients with bipolar mania (1 study; 16-week duration). Change in prolactin levels (ng/mL) from baseline to study endpoint was evaluated in subsets of sex and prior medication use.

RESULTS

In patients with schizophrenia (male, n = 1377; female, n = 558), median prolactin changes were -1.2 for males and -7.4 for females on placebo, and ranged from -4.2 to -3.6 for males and -12.4 to +0.2 for females in the cariprazine-treatment groups. In patients with bipolar mania (male, n = 570; female, n = 395), median prolactin changes were -0.2 for males and -1.1 for females on placebo and ranged from -2.1 to -3.0 for males and 0 to +1.8 for females in the cariprazine-treatment groups. Median decreases were also seen in the long-term studies of schizophrenia (range, -14.6 to -2.0) and bipolar mania (range, -0.8 to +1.9). In patients with bipolar depression (male, n = 485; female, n = 780), median prolactin changes were +0.3 for males and +0.7 for females on placebo and ranged from +0.4 to +0.5 for males and +3.0 to +3.1 for females in the cariprazine-treatment groups.

CONCLUSION

Treatment with cariprazine for schizophrenia or bipolar I disorder was associated with minimal effects on prolactin levels.

New Antipsychotic Medications in the Last Decade

PURPOSE OF REVIEW

Over the last ten years, the treatment of psychosis has seen a near explosion of creative development in both novel agents and new delivery modalities. The current review summarizes these developments over the past decade (2011-2020). We performed a systematic review utilizing PubMed and PsychInfo with the aim of identifying all the RCT and related analyses in adults with psychosis (schizophrenia and mania).

RECENT FINDINGS

We identified 11 significant developments: the introduction of new antipsychotics cariprazine, brexpiprazole, lumateperone, and pimavanserin; introduction of new delivery methods: subcutaneous long-acting risperidone, aripiprazole lauroxil, transdermal asenapine, and inhaled loxapine; and the introduction of new approaches such as olanzapine/samidorphan for olanzapine-associated weight gain, examination of the TAAR1 agonist SEP 363,856 as a test of concept, and the combination of Xanomeline/Trospium, an M₁ and M₄ muscarinic receptor agonist in conjunction with a peripheral anticholinergic. Last decade has seen a tremendous development in second-generation antipsychotics which provides unprecedented treatment options for clinicians in treating psychosis.

Cariprazine as a Treatment Option for Depressive Episodes Associated with Bipolar 1 Disorder in Adults: An Evidence-Based Review of Recent Data

Depressive episodes, the most frequent episodes in bipolar disorder, contribute in large part to poor functional outcomes. Very few treatments, however, have been approved by the Food and Drug Administration for the treatment of bipolar depression. Cariprazine, a broad-spectrum dopamine antagonist/partial agonist with dopamine D3/D2 (preferring D3) and serotonin 5-HT1A receptor partial agonist properties, was recently approved. A review of the literature suggests that it is an effective and well-tolerated treatment for bipolar depression.

Reducing Addiction in Bipolar Disorder via Hacking the Dopaminergic System

The dopaminergic system plays a central and decisive role in substance use disorder (SUD), bipolar disorder (BD), and possibly in a subgroup of patients with refractory depression. Common genetic markers and underlying cellular processes, such as kindling, support the close link between these disorders, which is also expressed by the high rate of comorbidity. Although partial dopamine agonists/antagonists acting on D₂ and D₃ receptors have an established role in treating BD, their usefulness in SUD is less clear. However, dopamine D₃ receptors were shown to play a central role in SUD and BD, making D₂/D₃ partial agonists/antagonists a potential target for both disorders. This narrative review examines whether these substances bear the promise of a future therapeutic approach especially in patients with comorbid BD and SUD.

Population Pharmacokinetics of Cariprazine and its Major Metabolites

BACKGROUND AND OBJECTIVES

Cariprazine, a dopamine D₃-preferring D₃/D₂ receptor partial agonist, is approved for the treatment of adults with schizophrenia (1.5-6 mg/day) and manic/mixed (3-6 mg/day) episodes associated with bipolar I disorder. This population pharmacokinetic analysis describes the concentration-time profiles of cariprazine and its two major active metabolites, desmethyl-cariprazine (DCAR) and didesmethyl-cariprazine (DDCAR). Additionally, the potential impact of patient characteristics, creatinine clearance, and cytochrome P450 2D6 (CYP2D6) metabolizer status on the pharmacokinetics of cariprazine and its metabolites was evaluated.

METHODS

Data from three phase 1 and ten phase 2/3 studies in adult patients with schizophrenia or bipolar mania were included. Nonlinear mixed-effects pharmacokinetic modeling was performed using the NONMEM software package. Compartmental modeling was performed sequentially with the cariprazine elimination rate used as the DCAR formation rate and likewise the elimination rate of DCAR used with a delay as the DDCAR formation rate.

RESULTS

Cariprazine pharmacokinetics were described by a three-compartment model with zero-order input of the dose to a depot compartment followed by first-order absorption and first-order elimination. DCAR and DDCAR pharmacokinetics were described by two-compartment models with linear elimination. Statistically significant predictors of pharmacokinetic parameters included weight, sex, and race, though differences in exposures were not large enough to require an adjustment in dose. Creatinine clearance was not a statistically significant predictor of drug clearance, and a post hoc analysis found that CYP2D6 metabolizer status was not associated with changes in exposure levels for cariprazine, DCAR, or DDCAR. The median time to 90% of steady state was approximately 1 week for cariprazine and DCAR and 3 weeks for DDCAR.

CONCLUSIONS

Population pharmacokinetic modeling provided a quantitative description of the concentration-time profile of cariprazine and its metabolites.

The role of dopamine D3 receptors in the mechanism of action of cariprazine

Cariprazine is a new atypical antipsychotic drug (APD) with a unique pharmacodynamic profile, different from both typical and atypical APDs. Specifically, cariprazine acts as a partial agonist at the dopamine (DA) D2 and D3 receptors and serotonin 5-HT1A receptors, and as an antagonist at the 5-HT2B receptors. Moreover, it shows moderate affinities for adrenergic, histaminergic, and cholinergic receptors that are involved in mediating the side effects characteristic of typical APDs. In this review, we discuss the contribution of DA D3 receptors (D3Rs) in the etiology and pathophysiology of schizophrenia and the potential benefits that may be associated with a more selective targeting of D3R by APDs, as compared to other dopaminergic and non-dopaminergic receptor subtypes. Cariprazine, by acting on D3Rs, ameliorates anhedonia and cognitive deficits in animal models based on environmental or pharmacological manipulation. The reviewed results support the potential benefits of cariprazine in treating negative symptoms and cognitive deficits of schizophrenia, and therefore representing a promising approach in addressing the unmet clinical needs for the improved treatment of this serious neuropsychiatric disorder.

Cariprazine as a treatment across the bipolar I spectrum from depression to mania: mechanism of action and review of clinical data

Cariprazine is one of the newest dopamine-serotonin partial agonists, also known as 'atypical' second generation antipsychotics. Originally approved for acute and maintenance treatment of schizophrenia as well as for acute mania and mixed mania/depression, cariprazine has now been approved for bipolar I depression. Additionally, post hoc analyses of bipolar I depressed subjects show that both those with and those without concurrent manic features were improved following treatment with cariprazine. Maintenance studies are in progress in bipolar disorder, as are studies to augment antidepressants in unipolar major depressive episodes insufficiently responsive to treatment. Here, we review specifically the efficacy and safety data of cariprazine in bipolar I disorder and discuss the hypothesized mechanism of action of cariprazine and how it could theoretically be linked to caprazine's broad therapeutic actions across the mood disorder spectrum.

Relationship Between Plasma Concentrations and Clinical Effects of Cariprazine in Patients With Schizophrenia or Bipolar Mania

Population pharmacokinetic/pharmacodynamic modeling (via NONMEM) was used to describe longitudinal exposure‐response relationships for total cariprazine (sum of cariprazine and its major active metabolites) in 2,558 patients with schizophrenia or bipolar mania. Drug exposure metrics were explored for potential relationships with efficacy and safety end points. Total cariprazine exposures were significantly related to reductions in Positive and Negative Syndrome Scale (PANSS) or Young Mania Rating Scale (YMRS) total scores in schizophrenia or bipolar mania, respectively, via a maximum effect (E_max)‐type relationship. Typical steady‐state plasma concentrations after 3 and 4.5 mg/day were associated with 50% of maximum typical reductions in PANSS and YMRS total scores, respectively. Time‐weighted cariprazine exposures had significant relationships with the probability of common adverse events (AEs). Dose increase was associated with increased efficacy but was also associated with an increase in AEs. Results of these pharmacokinetic/pharmacodynamic analyses support that the recommended dose range (1.5–6 mg/day for schizophrenia and 3–6 mg/day for bipolar mania) provides an appropriate benefit‐risk balance between cariprazine efficacy and safety.

Novel antipsychotics specificity profile: A clinically oriented review of lurasidone, brexpiprazole, cariprazine and lumateperone

Second generation antipsychotics (SGAs) are effective options in the treatment of schizophrenia and mood disorders, each with characteristic efficacy and safety features. In order to optimize the balance between efficacy and side effects, it is of upmost importance to match compound specificity against patient clinical profile. As the number of SGAs increased, this review can assist physicians in the prescription of three novel SGAs already on the market, namely lurasidone, brexpiprazole, cariprazine, and lumateperone, which is in the approval phase for schizophrenia treatment at the FDA. Besides schizophrenia, EMA and/or FDA approved lurasidone for bipolar depression, brexpiprazole as augmentation in major depressive disorder and cariprazine for the acute treatment of manic or mixed episodes associated with bipolar I disorder. These new antipsychotics were developed with the aim of improving efficacy on negative and depressive symptoms and reducing metabolic and cardiovascular side effects compared to prior SGAs, while keeping the risk of extrapyramidal symptoms low. They succeeded quite well in containing these side effects, despite weight gain during acute treatment remains a possible concern for brexpiprazole, while cariprazine and lurasidone show higher risk of akathisia compared to placebo and other SGAs such as olanzapine. The available studies support the expected benefits on negative symptoms, cognitive dysfunction and depressive symptoms, while the overall effect on acute psychotic symptoms may be similar to other SGAs such as quetiapine, aripiprazole and ziprasidone. The discussed new antipsychotics represent useful therapeutic options but their efficacy and side effect profiles should be considered to personalize prescription.

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.

Long-term safety and tolerability of cariprazine as adjunctive therapy in major depressive disorder

Lack of treatment response is a critical problem in major depressive disorder (MDD). Cariprazine is a D3-preferring dopamine D3/D2 receptor partial agonist and 5-HT1A partial agonist. This phase 3, multicenter, open-label, long-term (26-week), flexible-dose (1.5-4.5 mg/day) study assessed the long-term safety and tolerability of cariprazine used adjunctively with antidepressant therapy in adult patients with MDD who had either completed a lead-in study (n=311) or had been newly recruited (n=131). A higher percentage of continuing patients (66.2%) than new patients (35.9%) completed the study. The most common reason for discontinuation was adverse events (AEs; 13.9%); 79% of patients experienced a treatment-emergent AE [most common: akathisia (15.9%,) headache (11.6%)]. Serious AEs occurred in 2% of patients; two deaths occurred (one traffic accident, one completed suicide, both considered unrelated to treatment). The mean changes in clinical laboratory, cardiovascular, and ophthalmologic parameters were generally not clinically relevant. The mean (SD) changes from the open-label baseline in Montgomery-Åsberg Depression Rating Scale total score and Clinical Global Impression-Severity score at week 26 were -7.3 (9.5) and -1.0 (1.2), respectively. By week 26, 53.3% of patients were in remission (Montgomery-Åsberg Depression Rating Scale total score≤10). The results suggest that cariprazine was generally safe and well tolerated as adjunctive therapy to treat MDD.

Cariprazine for acute and maintenance treatment of adults with schizophrenia: an evidence-based review and place in therapy

Cariprazine is an oral antipsychotic approved in the US and EU for the treatment of schizophrenia. Cariprazine differs from other antipsychotics in that it is a dopamine D3- and D2-receptor partial agonist, with tenfold higher affinity for D3 receptors than for D2 receptors. Cariprazine is metabolized in two steps by CYP3A4 to didesmethyl-cariprazine (DDCAR). DDCAR has a long half-life of 1-3 weeks and is the predominant circulating active moiety. Efficacy and safety in persons with acute schizophrenia were assessed in four similarly designed, short-term, randomized, placebo-controlled clinical trials in nonelderly adults, with three studies considered positive and yielding a number needed to treat vs placebo for response (change from baseline ≥30% in Positive and Negative Syndrome Scale total score) of ten for the approved dose range of cariprazine 1.5-6 mg/day. The most common adverse reactions were extrapyramidal symptoms (15% and 19% for 1.5-3 and 4.5-6 mg/day, respectively, vs 8% for placebo) and akathisia (9% and 12.5% for 1.5-3 and 4.5-6 mg/day, respectively, vs 4% for placebo). For the approved dose range, rates of discontinuation because of an adverse event were lower overall for patients receiving cariprazine vs placebo (9% vs 12%). Weight and metabolic profile appear favorable. Cariprazine does not increase prolactin levels or prolong the electrocardiographic QT interval. Cariprazine has also been found to be effective for the maintenance treatment of schizophrenia by delaying time to relapse when compared with placebo (HR 0.45). A 26-week randomized clinical trial evidenced superiority of cariprazine over risperidone for the treatment of predominantly negative symptoms in patients with schizophrenia. Cariprazine is also approved in the US for the acute treatment of manic or mixed episodes associated with bipolar I disorder in adults and is being studied for the treatment of bipolar I depression and major depressive disorder.