Long-term safety and tolerability of iloperidone: results from a 25-week, open-label extension trial

Recent Advances in representative small-molecule DRD2 inhibitors: Synthetic Routes and clinical applications

The dopamine D2 receptor (DRD2) represents a pivotal target for therapeutic intervention in the treatment of neuropsychiatric disorders, including schizophrenia, bipolar disorder, and Parkinson's disease. The successful discovery of numerous effective DRD2 inhibitors has led to their clinical application and ongoing evaluation in various clinical trials. This review explores the synthetic approaches and clinical applications of prototypical small-molecule DRD2 inhibitors that have received approval or are currently undergoing clinical trials, highlighting their therapeutic potential and challenges. The synthesis of these inhibitors employs various chemical strategies, including modifications of phenothiazine and butyrophenone structures, which have yielded significant antipsychotic agents like chlorpromazine and haloperidol. Additionally, newer classes of inhibitors, such as aripiprazole, exhibit partial agonist activity at DRD2, offering a unique therapeutic profile. Clinically, DRD2 inhibitors demonstrate efficacy in managing positive symptoms of schizophrenia, manic episodes in bipolar disorder, and dopaminergic imbalance in Parkinson's disease. However, the emergence of adverse effects, including tardive dyskinesia, extrapyramidal symptoms and metabolic syndrome, presents substantial challenges. Advances in the development of second-generation antipsychotics aim to balance efficacy with a better side effect profile by targeting additional neurotransmitter receptors. This review aims to deliver an overview of the synthesis and clinical applications of representative small-molecule DRD2 inhibitors across various clinical phases, thereby offering strategic insights for the advancement of DRD2 inhibitor development.

A systematic review of the real-world effectiveness and economic and humanistic outcomes of selected oral antipsychotics among patients with schizophrenia in the United States: Updating the evidence and gaps

BACKGROUND

Schizophrenia is a chronic, relapsing, and burdensome psychiatric disorder affecting approximately 0.25%-0.6% of the US population. Oral antipsychotic treatment (OAT) remains the cornerstone for managing schizophrenia. However, nonadherence and high treatment failure lead to increased disease burden and medical spending. Cost-effective management of schizophrenia requires understanding the value of current therapies to facilitate better planning of management policies while addressing unmet needs.

OBJECTIVE

To review existing evidence and gaps regarding real-world effectiveness and economic and humanistic outcomes of OATs, including asenapine, brexpiprazole, cariprazine, iloperidone, lumateperone, lurasidone, olanzapine/samidorphan, paliperidone, and quetiapine.

METHODS

We conducted a literature search using PubMed, American Psychological Association PsycINFO (EBSCOhost), and the Cumulative Index of Nursing and Allied Health Literature from January 2010 to March 2022 as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. English-language articles describing adults with schizophrenia receiving at least 1 of the selected OATs and reporting real-world effectiveness, direct or indirect costs, humanistic outcomes, behavioral outcomes, adherence/persistence patterns, or product switching were identified.

RESULTS

We identified 25 studies from a total of 24,190 articles. Real-world effectiveness, cost, and adherence/persistence outcomes were reported for most OATs that were selected. Humanistic outcomes and product switching were reported only for lurasidone. Behavioral outcomes (eg, interpersonal relations and suicide ideation) were not reported for any OAT. The key economic outcomes across studies were incremental cost-effectiveness ratios, cost per quality-adjusted life-years, and health care costs. In studies that compared long-acting injectables (LAIs) with OATs, LAIs had a higher pharmacy and lower medical costs, while total health care cost was similar between LAIs and OATs. Indirect costs associated with presenteeism, absenteeism, or work productivity were not reported for any of the selected OATs. Overall, patients had poor adherence to OATs, ranging between 20% and 61% across studies. Product switching did not impact the all-cause health care costs before and after treatment.

CONCLUSIONS

Our findings showed considerable gaps exist for evidence on behavioral outcomes, humanistic outcomes, medication switching, and adherence/persistence across OATs. Our findings also suggest an unmet need regarding treatment nonadherence and lack of persistence among patients receiving OATs. We identified a need for research addressing OATs' behavioral and humanistic outcomes and evaluating the impact of product switching in adults with schizophrenia in the United States, which could assist clinicians in promoting patient-centered care and help payers understand the total value of new antipsychotic drugs.

The Effect of Chronic Iloperidone Treatment on Cytochrome P450 Expression and Activity in the Rat Liver: Involvement of Neuroendocrine Mechanisms

In order to achieve a desired therapeutic effect in schizophrenia patients and to maintain their mental wellbeing, pharmacological therapy needs to be continued for a long time, usually from the onset of symptoms and for the rest of the patients' lives. The aim of our present research is to find out the in vivo effect of chronic treatment with atypical neuroleptic iloperidone on the expression and activity of cytochrome P450 (CYP) in rat liver. Male Wistar rats received a once-daily intraperitoneal injection of iloperidone (1 mg/kg) for a period of two weeks. Twenty-four hours after the last dose, livers were excised to study cytochrome P450 expression (mRNA and protein) and activity, pituitaries were isolated to determine growth hormone-releasing hormone (GHRH), and blood was collected for measuring serum concentrations of hormones and interleukin. The results showed a broad spectrum of changes in the expression and activity of liver CYP enzymes, which are important for drug metabolism (CYP1A, CYP2B, CYP2C, and CYP3A) and xenobiotic toxicity (CYP2E1). Iloperidone decreased the expression and activity of CYP1A2, CP2B1/2, CYP2C11, and CYP3A1/2 enzymes but increased that of CYP2E1. The CYP2C6 enzyme remained unchanged. At the same time, the level of GHRH, GH, and corticosterone decreased while that of T₃ increased, with no changes in IL-2 and IL-6. The presented results indicate neuroendocrine regulation of the investigated CYP enzymes during chronic iloperidone treatment and suggest a possibility of pharmacokinetic/metabolic interactions produced by the neuroleptic during prolonged combined treatment with drugs that are substrates of iloperidone-affected CYP enzymes.

An update on the efficacy and safety of iloperidone as a schizophrenia therapy

INTRODUCTION

Schizophrenia has a prevalence of approximately 1% in the general population, with 15.2 per 100,000 persons affected. Iloperidone is a second-generation antipsychotic drug approved for the treatment of schizophrenia in adults. It acts primarily by D2/5HT2a receptor antagonism, with greater affinity for the 5HT2a receptor than for the D2 receptor.

AREAS COVERED

This article discusses iloperidone and aims to provide useful information for clinicians to determine which circumstances would best suit the use of iloperidone to treat schizophrenic patients. In this review, the authors briefly discuss schizophrenia and its treatment, before they discuss properties of iloperidone, its indications, approval process, and adverse effects. Finally, the authors review the specific strengths and weaknesses of the medication.

EXPERT OPINION

Iloperidone would be an attractive option in patients who are particularly prone to EPS, or who are showing prominent negative symptoms, as well as cognitive deficits. Its availability only in an oral formulation makes it a better option for patients with good medication adherence, and though it could be useful in patients prone to weight gain or hepatic dysfunction on other second generation antipsychotics, it should be used with caution in patients prone to side effects related to alpha adrenergic blockade.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

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.

Evaluation of the long-term safety and tolerability of cariprazine in patients with schizophrenia: results from a 1-year open-label study

OBJECTIVE

Cariprazine, a dopamine D3/D2 partial agonist atypical antipsychotic with preferential binding to D3 receptors, is approved for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder. The efficacy and safety of cariprazine was established in three randomized, double-blind, placebo-controlled, 6-week trials in patients with acute exacerbation of schizophrenia. This 53-week study evaluated the long-term safety and tolerability of cariprazine in patients with schizophrenia.

METHODS

This was a multicenter, open-label, flexible-dose study of cariprazine 3-9 mg/d in adults with schizophrenia. Participants included new patients and patients who had completed one of two phase III lead-in studies (NCT01104766, NCT01104779). Eligible patients entered a no-drug screening period of up to 1 week followed by 48 weeks of flexibly dosed, open-label cariprazine treatment (3-9 mg/d) and 4 weeks of safety follow-up.

RESULTS

A total of 586 patients received open-label cariprazine treatment, ~39% of whom completed the study. No unexpected safety issues or deaths were reported. The most common (≥10%) adverse events (AEs) observed were akathisia (16%), headache (13%), insomnia (13%), and weight gain (10%). Serious AEs occurred in 59 (10.1%) patients, and 73 (12.5%) patients discontinued the study due to AEs during open-label treatment. Mean changes in metabolic, hepatic, and cardiovascular parameters were not considered clinically relevant. Mean body weight increased by 1.5 kg during the study, prolactin levels decreased slightly, and measures of efficacy remained stable.

CONCLUSIONS

Long-term cariprazine treatment at doses up to 9 mg/d appeared to be generally safe and well tolerated in patients with schizophrenia.

The safety and tolerability of cariprazine in long-term treatment of schizophrenia: a post hoc pooled analysis

BACKGROUND

Schizophrenia is a chronic and debilitating neuropsychiatric disorder that often requires long-term pharmacotherapy to manage symptoms and prevent relapse. Cariprazine is a potent dopamine D₃ and D₂ receptor partial agonist that is FDA-approved in the US for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder in adults; the recommended dose range is 1.5-6 mg/d.

METHODS

To further characterize the long-term safety of cariprazine, data from two 48-week open-label, flexible-dose extension studies were pooled for post hoc analyses. Outcomes were evaluated in the pooled safety population (patients who received ≥1 dose of cariprazine during an open-label extension period); findings were summarized using descriptive statistics for the overall cariprazine group and in modal daily dose groups (1.5-3, 4.5-6, and 9 mg/d).

RESULTS

Of the 679 patients in the overall cariprazine safety population, 40.1% completed the study. The only adverse events (AEs) leading to discontinuation of ≥2% of patients in any dose group were akathisia, worsening of schizophrenia, and psychotic disorder. Treatment-emergent AEs (TEAEs) of akathisia, insomnia, weight increased, and headache were reported in ≥10% of the overall population. Mean prolactin levels decreased in all dose groups (overall, -15.4 ng/mL). Clinically insignificant changes in aminotransferase levels and alkaline phosphatase were observed; no dose-response relationship was observed across groups. Mean total (-5.3 mg/dL), low-density lipoprotein (-3.5 mg/dL), and high-density lipoprotein (-0.8 mg/dL) cholesterol levels decreased; no dose-response relationship was observed for metabolic parameters. Mean change in body weight was 1.58 kg; body weight increase and decrease ≥7% occurred in 27% and 11% of patients, respectively. Mean changes in cardiovascular parameters, including blood pressure and pulse, were generally not considered clinically significant. EPS-related TEAEs that occurred in ≥5% of patients were akathisia, tremor, restlessness, and extrapyramidal disorder.

CONCLUSION

In these post hoc pooled analyses of data from 2 long-term open-label studies, treatment with cariprazine was generally safe and well tolerated. Results support the safety and tolerability of cariprazine within the FDA-recommended dose range of 1.5-6 mg/d for schizophrenia.

CLINICAL TRIALS REGISTRATION

NCT01104792, NCT00839852.

Iloperidone in the treatment of schizophrenia: an evidence-based review of its place in therapy

Introduction

Schizophrenia is a chronic and debilitating mental disorder that affects the patient’s and their family’s quality of life, as well as financial costs and health care settings. Despite the variety of available antipsychotics, optimal treatment outcomes are not always achieved. Novel drugs, such as iloperidone, can provide more effective, tolerable and safer strategies.

Aim

To review the evidence for the clinical impact of iloperidone on the treatment of patients with schizophrenia.

Evidence review

Clinical trials, observational studies and meta-analyses reached a common consensus that iloperidone is as effective as haloperidol, risperidone and ziprasidone in reducing schizophrenia symptoms. Similar amounts of adverse events and discontinuations were observed with iloperidone compared to placebo and active treatments. Common adverse events are mild and include dizziness, hypotension, dry mouth and weight gain. Iloperidone can induce extension of QTc interval, and clinicians should be aware of its contraindications. In long-term trials, iloperidone also showed promising safety and tolerability profiles. The low propensity to cause akathisia, extrapyramidal symptoms (EPS), increased prolactin levels or changes to metabolic laboratory parameters support its use in practice. Results showed that iloperidone prevents relapse in stabilized patients, with a time to relapse superior to placebo and similar to haloperidol. Patients using a prior antipsychotic (eg, risperidone and aripiprazole) can easily switch to iloperidone with no serious impact on safety or efficacy. However, the acquisition costs of iloperidone may hamper its use. Further evidence comparing iloperidone with other antipsychotics, and pharmacoeconomic studies would be welcome.

Place in therapy

Considering just the clinical profile of iloperidone, it represents a promising drug for treating schizophrenia, particularly in patients who are intolerant to previous antipsychotics, as well as being suitable as first-line therapy. Cost-effectiveness comparisons are needed to justify its use in clinical practice.

A Randomized Trial of Iloperidone for Prevention of Relapse in Schizophrenia: The REPRIEVE Study

BACKGROUND

The purpose of this study was to evaluate the safety and effectiveness of iloperidone for the prevention of relapse in schizophrenia.

METHODS

Study subjects were adults with schizophrenia who started on oral open-label iloperidone titrated to an initial target dose of 12 mg/day (6 mg twice daily) and then stabilized on a flexible-dose iloperidone regimen (range 8-24 mg/day) for up to 24 weeks. Subjects meeting stabilization criteria then entered the relapse-prevention phase and were randomized 1:1 in a double-blind fashion to continue with iloperidone or placebo withdrawal for up to 26 weeks or until meeting relapse or other withdrawal criteria.

RESULTS

A total of 303 subjects were randomized to the relapse-prevention phase; 153 continued to receive iloperidone, and 150 were withdrawn to placebo. The modal total daily dose for iloperidone in all phases of the study was 12 mg/day. The pre-defined unblinded interim analysis upon reaching 68 relapse events confirmed the hypothesis that iloperidone (n = 97) was more effective than placebo (n = 96) in preventing relapse events, and the trial was stopped early. The estimated relapse rates were 63.4 % (Kaplan-Meier [KM] estimate) for placebo compared with 20.4 % (KM estimate) for those continuing to receive iloperidone (log rank test: p < 0.0001). The mean time to relapse was 71 days for placebo and 139 days for iloperidone (hazard ratio 4.7; 95 % confidence interval 2.7-8.3; p < 0.0001). The safety profile observed in previous short-term studies was also reaffirmed in this maintenance treatment setting. The most common treatment-emergent adverse events (TEAEs) in the stabilization phase were dizziness (11.6 %), somnolence (8.3 %), and dry mouth (6.8 %). Rates of reported extrapyramidal disorder or akathisia during stabilization were 2.5 and 3.7 %, respectively.

CONCLUSIONS

Flexible dosing of iloperidone for maintenance-phase therapy, with a modal dose of 12 mg/day was effective in preventing relapse in subjects previously stabilized on iloperidone. The adverse event profile for iloperidone was consistent with other studies, and the low extrapyramidal symptom and akathisia burden during stabilization was sustained during the course of the study. ClinicalTrials.gov identifier: NCT01291511.

Weight gain and antipsychotics: a drug safety review

INTRODUCTION

Second-generation antipsychotics (SGAs) are widely used in several psychiatric disease entities and exert to a different extent a risk for antipsychotic-induced weight gain (AIWG). As AIWG is associated with an increase in metabolic syndrome or cardiovascular events, knowledge of these risks is crucial for further monitoring and the initiation of counteractive measures.

AREAS COVERED

We searched PubMed and Web of Sciences for randomized-controlled trials and naturalistic observational studies published between 2010 and 2014 with sample sizes exceeding 100, including all marketed SGAs apart from zotepine, and providing data on weight increase. We also summarized relevant systematic reviews and meta-analyses of head-to-head comparisons.

EXPERT OPINION

Recently published data still support the hierarchical ranking of SGAs already proposed in previous reviews ranking clozapine and olanzapine as having the highest risk, followed by amisulpride, asenapine, iloperidone, paliperidone, quetiapine, risperidone and sertindole in the middle, and aripiprazole, lurasidone and ziprasidone with the lowest risk. Number needed to harm varied considerably in our meta-analysis. Younger patients and patients with a lower baseline body mass index are most vulnerable. The greatest amount of weight gain occurs within the first weeks of treatment. AIWG occurs in all diagnostic groups and is also common in treatment with first-generation antipsychotics; therefore, awareness of this adverse event is essential for anyone prescribing antipsychotics.

The effects of novel and newly approved antipsychotics on serum prolactin levels: a comprehensive review

Since the 1970s, clinicians have increasingly become more familiar with hyperprolactinemia (HPRL) as a common adverse effect of antipsychotic medication, which remains the cornerstone of pharmacological treatment for patients with schizophrenia. Although treatment with second-generation antipsychotics (SGAs) as a group is, compared with use of the first-generation antipsychotics, associated with lower prolactin (PRL) plasma levels, the detailed effects on plasma PRL levels for each of these compounds in reports often remain incomplete or inaccurate. Moreover, at this moment, no review has been published about the effect of the newly approved antipsychotics asenapine, iloperidone and lurasidone on PRL levels. The objective of this review is to describe PRL physiology; PRL measurement; diagnosis, causes, consequences and mechanisms of HPRL; incidence figures of (new-onset) HPRL with SGAs and newly approved antipsychotics in adolescent and adult patients; and revisit lingering questions regarding this hormone. A literature search, using the MEDLINE database (1966-December 2013), was conducted to identify relevant publications to report on the state of the art of HPRL and to summarize the available evidence with respect to the propensity of the SGAs and the newly approved antipsychotics to elevate PRL levels. Our review shows that although HPRL usually is defined as a sustained level of PRL above the laboratory upper limit of normal, limit values show some degree of variability in clinical reports, making the interpretation and comparison of data across studies difficult. Moreover, many reports do not provide much or any data detailing the measurement of PRL. Although the highest rates of HPRL are consistently reported in association with amisulpride, risperidone and paliperidone, while aripiprazole and quetiapine have the most favorable profile with respect to this outcome, all SGAs can induce PRL elevations, especially at the beginning of treatment, and have the potential to cause new-onset HPRL. Considering the PRL-elevating propensity of the newly approved antipsychotics, evidence seems to indicate these agents have a PRL profile comparable to that of clozapine (asenapine and iloperidone), ziprasidone and olanzapine (lurasidone). PRL elevations with antipsychotic medication generally are dose dependant. However, antipsychotics having a high potential for PRL elevation (amisulpride, risperidone and paliperidone) can have a profound impact on PRL levels even at relatively low doses, while PRL levels with antipsychotics having a minimal effect on PRL, in most cases, can remain unchanged (quetiapine) or reduce (aripiprazole) over all dosages. Although tolerance and decreases in PRL values after long-term administration of PRL-elevating antipsychotics can occur, the elevations, in most cases, remain above the upper limit of normal. PRL profiles of antipsychotics in children and adolescents seem to be the same as in adults. The hyperprolactinemic effects of antipsychotic medication are mostly correlated with their affinity for dopamine D2 receptors at the level of the anterior pituitary lactotrophs (and probably other neurotransmitter mechanisms) and their blood-brain barrier penetrating capability. Even though antipsychotics are the most common cause of pharmacologically induced HPRL, recent research has shown that HPRL can be pre-existing in a substantial portion of antipsychotic-naïve patients with first-episode psychosis or at-risk mental state.

Second-generation and newly approved antipsychotics, serum prolactin levels and sexual dysfunctions: a critical literature review

INTRODUCTION

Using antipsychotic (AP) medication can increase prolactin (PRL) levels and place the patient at risk of sexual dysfunction (SD).

AREAS COVERED

The aim of this review is to describe the PRL propensity of the different second-generation and newly approved APs. It then considers the prevalence rates of SDs associated with these compounds in patients with schizophrenia and treatment strategies for the management of SDs and/or hyperprolactinemia (HPRL). Furthermore, we address the lingering question regarding the association between SDs and PRL.

EXPERT OPINION

SD (particularly long-term) data remain scarce for several APs. A wide variety of assessment techniques used in SD research make reliable comparisons between APs impossible. The majority of these reports do not equally allow us to distinguish between treatment (AP and co-medication)-emergent SDs and illness-related SDs. This makes it difficult to assess the degree to which these side effects are associated with 'PRL-raising' APs, and what part of this fraction is directly reducible to serum PRL levels. Also, few evidence-based treatment strategies for HPRL and associated side effects are available. Therefore, longer-term randomized controlled trials, using reliable and valid structured interviews or questionnaires, are necessary to establish the precise relationship between APs, PRL levels and SDs rates and develop valuable treatment options.

Long-term efficacy and safety of iloperidone: an update

Schizophrenia is a devastating neuropsychiatric disease with a worldwide prevalence of approximately 0.5%-1%. Since many patients do not achieve adequate symptom relief from available agents, alternate pharmacotherapeutic approaches are needed. In this context, iloperidone was recently approved by the US Food and Drug Administration for the treatment of schizophrenia. This paper first reviews its pharmacodynamic and pharmacokinetic profiles, emphasizing their clinical relevance. Next, it summarizes the literature on its acute and maintenance efficacy, safety, and tolerability. It then considers pharmacogenetic data which may help to predict response and risk of cardiac arrhythmias with this agent. Finally, it critically positions iloperidone relative to other first- and second-generation antipsychotics.

Role of α1 adrenergic antagonism in the mechanism of action of iloperidone: reducing extrapyramidal symptoms

The low incidence of extrapyramidal side effects associated with the atypical antipsychotic iloperidone may be linked to its unique binding profile of high affinity antagonism of both α1 adrenergic receptors and serotonin 2A receptors.

A review of the pharmacology, efficacy and tolerability of recently approved and upcoming oral antipsychotics: an evidence-based medicine approach

Evidence-based medicine (EBM) is a broad concept, but the key elements include the incorporation of clinical judgment (which requires clinical experience) together with relevant scientific evidence while remaining mindful of the individual patient's values and preferences. Using the framework and philosophy of EBM, this systematic review summarizes the pharmacology, efficacy, and tolerability of newly approved oral antipsychotics, including iloperidone, asenapine, and lurasidone, and outlines what is known about agents that are in late-stage clinical development, such as cariprazine, brexpiprazole, zicronapine, bitopertin, and EVP-6124. Potential advantages and disadvantages of these agents over existing antipsychotics are outlined, centered on clinically relevant issues such as the potential for weight gain and metabolic abnormalities, potential association with somnolence/sedation, extra-pyramidal side effects, akathisia, and prolongation of the electrocardiogram (ECG) QT interval, as well as practical issues regarding dosing instructions, titration requirements, and drug-drug interactions. Lurasidone appears to be best in class in terms of minimizing untoward alterations in body weight and metabolic variables. However, iloperidone, asenapine, lurasidone, and cariprazine differ among themselves in terms of on-label dosing frequency (once daily for lurasidone and, presumably, cariprazine versus twice daily for iloperidone and asenapine), the need for initial titration to a therapeutic dose for iloperidone and possibly cariprazine, requirement to be taken sublingually for asenapine, requirement for administration with food for lurasidone, lengthening of the ECG QT interval (greater for iloperidone than for asenapine and no effect observed with lurasidone), and adverse effects such as akathisia (seen with cariprazine, lurasidone, and asenapine but not with iloperidone) and sedation (most notable with asenapine).