Loxapine inhibits replication of hepatitis A virus in vitro and in vivo by targeting viral protein 2C.

No antiviral drugs currently are available for treatment of infection by hepatitis A virus (HAV), a causative agent of acute hepatitis, a potentially life-threatening disease. Chemical screening of a small-compound library using nanoluciferase-expressing HAV identified loxapine succinate, a selective dopamine receptor D2 antagonist, as a potent inhibitor of HAV propagation in vitro. Loxapine succinate did not inhibit viral entry nor internal ribosome entry site (IRES)-dependent translation, but exhibited strong inhibition of viral RNA replication. Blind passage of HAV in the presence of loxapine succinate resulted in the accumulation of viruses containing mutations in the 2C-encoding region, which contributed to resistance to loxapine succinate. Analysis of molecular dynamics simulations of the interaction between 2C and loxapine suggested that loxapine binds to the N-terminal region of 2C, and that resistant mutations impede these interactions. We further demonstrated that administration of loxapine succinate to HAV-infected Ifnar1-/- mice (which lack the type I interferon receptor) results in decreases in the levels of fecal HAV RNA and of intrahepatic HAV RNA at an early stage of infection. These findings suggest that HAV protein 2C is a potential target for antivirals, and provide novel insights into the development of drugs for the treatment of hepatitis A.

Discovery of a Small Molecule Activator of Slack (Kcnt1) Potassium Channels That Significantly Reduces Scratching in Mouse Models of Histamine-Independent and Chronic Itch.

Various disorders are accompanied by histamine-independent itching, which is often resistant to the currently available therapies. Here, it is reported that the pharmacological activation of Slack (Kcnt1, KNa1.1), a potassium channel highly expressed in itch-sensitive sensory neurons, has therapeutic potential for the treatment of itching. Based on the Slack-activating antipsychotic drug, loxapine, a series of new derivatives with improved pharmacodynamic and pharmacokinetic profiles is designed that enables to validate Slack as a pharmacological target in vivo. One of these new Slack activators, compound 6, exhibits negligible dopamine D2 and D3 receptor binding, unlike loxapine. Notably, compound 6 displays potent on-target antipruritic activity in multiple mouse models of acute histamine-independent and chronic itch without motor side effects. These properties make compound 6 a lead molecule for the development of new antipruritic therapies targeting Slack.

Alternative Approaches for Addressing Acute Agitation in Schizophrenia and Bipolar Disorder.

Importance: The prompt effective treatment of acute agitation among patients with schizophrenia or bipolar disorder can alleviate distressing symptoms for the patient and decrease the risk of escalation to aggression and the potential for serious harm to the patient, health care providers, and others.Observations: A commonly used approach for the management of acute agitation has been the intramuscular administration of antipsychotic medications and/or benzodiazepines. However, US Food and Drug Administration-approved treatments with alternative routes of delivery now include inhaled loxapine powder and, more recently, dexmedetomidine sublingual film. Two formulations of intranasal olanzapine for acute agitation are in development.Conclusions and Relevance: Intranasal formulations offer the potential for favorable pharmacokinetics and onset of action combined with ease of delivery obviating the need for injections and are thus consistent with patient-centered factors such as preference and self-administration. In this review, alternative methods of medication delivery are discussed, with an emphasis on the potential for intranasal administration to treat acute agitation in adult patients with schizophrenia or bipolar disorder.Prim Care Companion CNS Disord 2024;26(1):23nr03596. Author affiliations are listed at the end of this article.

Efficacy and Safety of Loxapine in Acute Agitation: A Systematic Review of Interventional Studies.

Objective: To assess the efficacy and safety of loxapine in acute agitation.Data Sources: PubMed, Cochrane database, EMBASE, PsycINFO, and ClinicalTrials.gov were searched to identify relevant articles published in English or French from inception to March 15, 2022. The term "Loxap*" was searched in titles and abstracts.Study Selection and Data Extraction: Interventional studies that compared the effectiveness of loxapine to any other intervention (including another administration route or dosage of loxapine, other drugs, and placebo) in acute agitation were included. From the 1,435 articles initially identified, and after the assessment of 73 full texts, 7 articles were selected, encompassing 1,276 participants. Two reviewers independently extracted data of interest using a predefined form.Results: Among included studies, 5 were double-blind, 2 were open-label, and all were randomized. The risk of bias was low for 2 studies, involving 658 participants. Four articles compared loxapine to placebo, and 3 compared it with haloperidol, aripiprazole, and droperidol. Loxapine was found to be more effective and faster regarding acute agitation control. Also, across included studies, loxapine was well-tolerated, with mildly or moderately severe adverse effects.Conclusions: Notwithstanding methodological limitations of the included studies, this systematic review provides reassuring results regarding the use of loxapine in acute agitation. However, further studies with methodological optimizations might be of interest.Prim Care Companion CNS Disord 2023;25(6):23r03552. Author affiliations are listed at the end of this article.

Improving the pharmacotherapeutic treatment of agitation associated with bipolar disorder.

INTRODUCTION: Agitation is commonly encountered in people with bipolar disorder, particularly when experiencing a manic episode. The number of approved pharmacological agents to manage acute episodes of agitation in this population is limited. AREAS COVERED: A search was conducted using the US National Library of Medicine PubMed.gov resource for English-language papers of clinical trials and reviews/meta-analyses, using the text words 'bipolar disorder' AND 'agitation,' as well as any papers with both two text words in the title, without any date restrictions. EXPERT OPINION: Existing pharmacologic options approved by regulatory authorities for the treatment of acute episodes of agitation associated with bipolar disorder have similar degrees of efficacy but differ in their tolerability profiles and ease of use, giving clinicians an opportunity to individualize treatment. The goal is to treat mild-moderate agitation before it evolves into severe agitation, encouraging noninvasive pharmacologic treatment options. Inhaled loxapine and sublingual dexmedetomidine are newer options with rapid onset of action and may be preferable for patients willing to cooperate with treatment.

Actionable Predictive Factors of Homelessness in a Psychiatric Population: Results from the REHABase Cohort Using a Machine Learning Approach.

BACKGROUND: There is a lack of knowledge regarding the actionable key predictive factors of homelessness in psychiatric populations. Therefore, we used a machine learning model to explore the REHABase database (for rehabilitation database-n = 3416), which is a cohort of users referred to French psychosocial rehabilitation centers in France. METHODS: First, we analyzed whether the different risk factors previously associated with homelessness in mental health were also significant risk factors in the REHABase. In the second step, we used unbiased classification and regression trees to determine the key predictors of homelessness. Post hoc analyses were performed to examine the importance of the predictors and to explore the impact of cognitive factors among the participants. RESULTS:  First, risk factors that were previously found to be associated with homelessness were also significant risk factors in the REHABase. Among all the variables studied with a machine learning approach, the most robust variable in terms of predictive value was the nature of the psychotropic medication (sex/sex relative mean predictor importance: 22.8, σ = 3.4). Post hoc analyses revealed that first-generation antipsychotics (15.61%; p < 0.05 FDR corrected), loxapine (16.57%; p < 0.05 FWER corrected) and hypnotics (17.56%; p < 0.05 FWER corrected) were significantly associated with homelessness. Antidepressant medication was associated with a protective effect against housing deprivation (9.21%; p < 0.05 FWER corrected). CONCLUSIONS: Psychotropic medication was found to be an important predictor of homelessness in our REHABase cohort, particularly loxapine and hypnotics. On the other hand, the putative protective effect of antidepressants confirms the need for systematic screening of depression and anxiety in the homeless population.

Fifty years of experience with loxapine for the rapid non-coercive tranquilization of acute behavioral disturbances in schizophrenia patients, and beyond.

INTRODUCTION: Acute behavioral disturbances in psychosis, including agitation, comprise a heterogeneous group of manifestations varying in intensity and duration they last for. They require rapid, non-coercive treatments ranging from verbal de-escalation to the calming effect of pharmacological agents. The treatment goals are reduction of patient suffering and prevention of disease deterioration. Stabilizing rather than sedating is preferred to ensure improved compliance and a stronger therapeutic alliance. Furthermore, animal pharmacology and clinical studies on agitation reveal the robust calming and anxiolytic properties of loxapine. AREAS COVERED: This review covers the pharmacological and clinical history of loxapine along with research developments. It emphasizes the advantages of its multiple formulations ranging from injectable forms and tablets to orally inhaled forms to attain rapid and fine-tuned tranquilization. EXPERT OPINION: Rapid tranquillization is achieved within 2-6 hours using liquid orally-consumed loxapine, and within an hour or less with its IM or orally inhaled forms. Loxapine has been adopted in the management of a wide range of acute disturbances, such as agitation in psychosis. In the context of personalized medicine, key cellular and molecular elements of the schizophrenia phenotype were recently shown to be improved with loxapine.

A Novel Dibenzoxazepine Attenuates Intracellular Salmonella Typhimurium Oxidative Stress Resistance.

Salmonella enterica serovar Typhimurium is the leading cause of invasive nontyphoidal salmonellosis. Additionally, the emergence of multidrug-resistant S. Typhimurium has further increased the difficulty of controlling its infection. Previously, we showed that an antipsychotic drug, loxapine, suppressed intracellular Salmonella in macrophages. To exploit loxapine's antibacterial activity, we simultaneously evaluated the anti-intracellular Salmonella activity and cytotoxicity of newly synthesized loxapine derivatives using an image-based high-content assay. We identified that SW14 exhibits potent suppressive effects on intramacrophagic S. Typhimurium with an 50% effective concentration (EC50) of 0.5 µM. SW14 also sensitized intracellular Salmonella to ciprofloxacin and cefixime and effectively controlled intracellular multidrug- and fluoroquinolone-resistant S. Typhimurium strains. However, SW14 did not affect bacterial growth in standard microbiological broth or minimal medium that mimics the phagosomal environment. Cellular autophagy blockade by 3-methyladenine (3-MA) or shATG7 elevated the susceptibility of intracellular Salmonella to SW14. Finally, reactive oxygen species (ROS) scavengers reduced the antibacterial efficacy of SW14, but the ROS levels in SW14-treated macrophages were not elevated. SW14 decreased the resistance of outer membrane-compromised S. Typhimurium to H2O2. Collectively, our data indicated that the structure of loxapine can be further optimized to develop new antibacterial agents by targeting bacterial resistance to host oxidative-stress defense. IMPORTANCE The incidence of diseases caused by pathogenic bacteria with resistance to common antibiotics is consistently increasing. In addition, Gram-negative bacteria are particularly difficult to treat with antibiotics, especially those that can invade and proliferate intracellularly. In order to find a new antibacterial compound against intracellular Salmonella, we established a cell-based high-content assay and identified SW14 from the derivatives of the antipsychotic drug loxapine. Our data indicate that SW14 has no effect on free bacteria in the medium but can suppress the intracellular proliferation of multidrug-resistant (MDR) S. Typhimurium in macrophages. We also found that SW14 can suppress the resistance of outer membrane compromised Salmonella to H2O2, and its anti-intracellular Salmonella activity can be reversed by reactive oxygen species (ROS) scavengers. Together, the findings suggest that SW14 might act via a virulence-targeted mechanism and that its structure has the potential to be further developed as a new therapeutic against MDR Salmonella.

Effect of Novel Antipsychotics on Energy Metabolism - In Vitro Study in Pig Brain Mitochondria.

The identification and quantification of mitochondrial effects of novel antipsychotics (brexpiprazole, cariprazine, loxapine, and lurasidone) were studied in vitro in pig brain mitochondria. Selected parameters of mitochondrial metabolism, electron transport chain (ETC) complexes, citrate synthase (CS), malate dehydrogenase (MDH), monoamine oxidase (MAO), mitochondrial respiration, and total ATP and reactive oxygen species (ROS) production were evaluated and associated with possible adverse effects of drugs. All tested antipsychotics decreased the ETC activities (except for complex IV, which increased in activity after brexpiprazole and loxapine addition). Both complex I- and complex II-linked respiration were dose-dependently inhibited, and significant correlations were found between complex I-linked respiration and both complex I activity (positive correlation) and complex IV activity (negative correlation). All drugs significantly decreased mitochondrial ATP production at higher concentrations. Hydrogen peroxide production was significantly increased at 10 µM brexpiprazole and lurasidone and at 100 µM cariprazine and loxapine. All antipsychotics acted as partial inhibitors of MAO-A, brexpiprazole and loxapine partially inhibited MAO-B. Based on our results, novel antipsychotics probably lacked oxygen uncoupling properties. The mitochondrial effects of novel antipsychotics might contribute on their adverse effects, which are mostly related to decreased ATP production and increased ROS production, while MAO-A inhibition might contribute to their antidepressant effect, and brexpiprazole- and loxapine-induced MAO-B inhibition might likely promote neuroplasticity and neuroprotection. The assessment of drug-induced mitochondrial dysfunctions is important in development of new drugs as well as in the understanding of molecular mechanism of adverse or side drug effects.

Inhaled loxapine for acute agitation in a psychiatric emergency service.

BACKGROUND: Rapid control of agitation in medical settings is necessary for safety and provision of care. Inhaled loxapine achieves peak plasma levels within 2 minutes of administration and is FDA-approved for managing acute agitation. METHODS: We examined the use of inhaled loxapine vs non-parenteral treatment as usual (TAU) in a psychiatric emergency service for consecutive patients with acute agitation or aggression. Data were collected retrospectively. T tests were used for continuous variables and Chi-square tests were used for categorical data. RESULTS: A total of 61 patients received inhaled loxapine and 29 received TAU. Time to outcome for patients receiving inhaled loxapine was 21 ± 21 minutes compared with 121 ± 206 minutes for TAU (t =-2.61; P = .014). At outcome, 89% of patients treated with loxapine experienced symptom resolution, compared with 69% of TAU (Chi-square = 17.4, P < .0001). Ten percent of patients receiving loxapine had no change in symptoms and 1% had worsening symptoms vs 14% in the TAU group who experienced no change in symptoms (z = 0.5, not significant), and 17% who described worsening symptoms (z = 6153.9, P < .0001). CONCLUSIONS: The rapid absorption of inhaled loxapine is associated with a 6-fold faster and more robust symptom control.

The Management of Psychomotor Agitation Associated with Schizophrenia or Bipolar Disorder: A Brief Review.

The early and correct assessment of psychomotor agitation (PMA) is essential to ensure prompt intervention by healthcare professionals to improve the patient's condition, protect healthcare staff, and facilitate future management. Proper training for recognizing and managing agitation in all care settings is desirable to improve patient outcomes. The best approach is one that is ethical, non-invasive, and respectful of the patient's dignity. When deemed necessary, pharmacological interventions must be administered rapidly and avoid producing an excessive state of sedation, except in cases of severe and imminent danger to the patient or others. The purpose of this brief review is to raise awareness about best practices for the management of PMA in emergency care situations and consider the role of new pharmacological interventions in patients with agitation associated with bipolar disorder or schizophrenia.

Agitation in schizophrenia: origins and evidence-based treatment.

PURPOSE OF REVIEW: Agitation associated with schizophrenia remains an important clinical concern and if not managed effectively, can escalate into aggressive behavior. This is a review of the recent biomedical literature on agitation in individuals with schizophrenia. RECENT FINDINGS: Themes in the recent literature include consideration of comorbidities such as cigarette smoking and cannabis use. Surveys reveal that pharmacological approaches to manage agitation have changed little, with haloperidol remaining in common use and intramuscular administration of antipsychotics and/or benzodiazepines being frequently administered to more severely agitated/aggressive individuals. Of note, ketamine has been recently adopted for use in severe agitation in medical emergency departments, but the risk of this medication for people with schizophrenia is unclear. At present, inhaled loxapine remains the only rapidly acting noninjectable FDA-approved treatment for agitation associated with schizophrenia. In development is an intranasal formulation for olanzapine (a well characterized atypical antipsychotic already approved to treat agitation) and a sublingual film for dexmedetomidine (an α2-adrenergic agonist used as an anesthetic and now being repurposed). SUMMARY: Comorbidities can contribute to agitation and can make an accurate differential diagnosis challenging. The ongoing development of rapidly acting novel formulations of antiagitation medications, if successful, may facilitate clinical treatment by providing additional options.

Haematologic malignancies associated with clozapine v. all other antipsychotic agents: a pharmacovigilance study in VigiBase®.

BACKGROUND: Clozapine is mainly used in patients with treatment-resistant schizophrenia and may lead to potentially severe haematologic adverse events, such as agranulocytosis. Whether clozapine might be associated with haematologic malignancies is unknown. We aimed to assess the association between haematologic malignancies and clozapine using Vigibase®, the WHO pharmacovigilance database. METHODS: We performed a disproportionality analysis to compute reporting odds-ratio adjusted for age, sex and concurrent reporting of antineoplastic/immunomodulating agents (aROR) for clozapine and structurally related drugs (loxapine, olanzapine and quetiapine) compared with other antipsychotic drugs. Cases were malignant lymphoma and leukaemia reports. Non-cases were all other reports including at least one antipsychotic report. RESULTS: Of the 140 226 clozapine-associated reports, 493 were malignant lymphoma cases, and 275 were leukaemia cases. Clozapine was significantly associated with malignant lymphoma (aROR 9.14, 95% CI 7.75-10.77) and leukaemia (aROR 3.54, 95% CI 2.97-4.22). Patients suffering from those haematologic malignancies were significantly younger in the clozapine treatment group than patients treated with other medicines (p < 0.001). The median time to onset (available for 212 cases) was 5.1 years (IQR 2.2-9.9) for malignant lymphoma and 2.5 years (IQR 0.6-7.4) for leukaemia. The aROR by quartile of dose of clozapine in patients with haematologic malignancies suggested a dose-dependent association. CONCLUSIONS: Clozapine was significantly associated with a pharmacovigilance signal of haematologic malignancies. The risk-benefit balance of clozapine should be carefully assessed in patients with risk factors of haematologic malignancies. Clozapine should be used at the lowest effective posology.

Management of Acute Agitation and Aggression in Children and Adolescents with Pro Re Nata Oral Immediate Release Antipsychotics in the Pediatric Emergency Department.

Background: Acute agitation in the pediatric emergency department (ED) has the potential to escalate into aggression and result in harm. Rapid and effective management may be warranted. Use of pro re nata (prn) oral immediate-release (IR) quetiapine, haloperidol, loxapine, and chlorpromazine has been observed in the pediatric ED at Surrey Memorial Hospital to manage this condition; however, evidence for oral prn antipsychotic use is limited in the pediatric population. Objectives: The primary objective is to characterize the dose of prn oral IR quetiapine used to manage acute agitation or aggression in a pediatric ED. Secondary objectives include characterizing the dose of prn oral IR haloperidol, loxapine, and chlorpromazine; and describing the 1-hour response rate, admission rate, length of stay (LOS), and adverse drug effects. Method: The medical records of pediatric patients who received at least one prn oral dose of IR quetiapine, haloperidol, loxapine, or chlorpromazine for acute agitation and aggression, without regard to the etiology of symptom presentation, between January 1, 2012 and December 31, 2016, were analyzed retrospectively. Results: Sixty-nine patients met the inclusion criteria. The mean dose of quetiapine was 32 mg/dose (0.54 mg/kg per dose); and the response rate was 53%. The mean haloperidol, loxapine, and chlorpromazine doses were 4 mg (0.07 mg/kg per dose), 13 mg (0.19 mg/kg per dose), and 29 mg/dose (0.53 mg/kg per dose) respectively; and the response rates were 36%, 30%, and 50%, respectively. Between 19% and 60% of patients were admitted, majority to the psychiatry ward. The median LOS in the ED was between 5 and 18 hours for nonadmitted patients. Extrapyramidal side effects (EPS) were reported with first-generation antipsychotics (FGA), but not with quetiapine. Conclusion: Quetiapine appears to be a viable agent for managing acute agitation and aggression in the pediatric ED with low rates of EPS. Further studies are encouraged to compare the effectiveness of quetiapine with FGA. A Clinical Trial Registration number is not applicable for this study.

Loxapine, an antipsychotic drug, suppresses intracellular multiple-antibiotic-resistant Salmonella enterica serovar Typhimurium in macrophages.

BACKGROUND: The emergence of multiple-antibiotic-resistant (MAR) Salmonella has been a serious threat worldwide. Salmonella can invade into host cells and evade the attacks of host humoral defenses and antibiotics. Thus, a new antibacterial agent capable of inhibiting intracellular Salmonella is highly needed. METHODS: The anti-intracellular activity and cytotoxicity of drugs on intracellular bacteria and macrophages were assayed using intracellular CFU assay and MTT cell viability assay, respectively. The uptake of gentamicin into macrophage and the effect of autophagy inhibitor on loxapine's anti-intracellular Salmonella activity were assessed by using image-based high-content system. The expression of bacterial genes was measured by real-time PCR. The efflux pump activity of bacteria was measured by Hoechst accumulation assays. RESULTS: With our efforts, an antipsychotic drug, loxapine, was identified to exhibit high potency in suppressing intracellular MAR S. Typhimurium, Staphylococcus aureus, Shigella flexneri or Yersinia enterocolitica. Subsequent investigations indicated that loxapine's anti-intracellular bacteria activity was not associated with increased penetration of gentamicin into bacteria and macrophages. Loxapine didn't inhibit bacterial growth in broth at concentration up to 500 µM and has no effect on Salmonella's type III secretion system genes' expression. Blockage of autophagy also didn't reverse loxapine's anti-intracellular activity. Lastly, loxapine suppressed bacterial efflux pump activity in all bacteria tested. CONCLUSION: Altogether, our data suggested that loxapine might suppress intracellular bacteria through inhibiting of bacterial efflux pumps. In light of its unique activity, loxapine represents a promising lead compound with translational potential for the development of a new antibacterial agent against intracellular bacteria.

Inhaled Loxapine for the Management of Acute Agitation in Bipolar Disorder and Schizophrenia: Expert Review and Commentary in an Era of Change.

Agitation is a common and costly phenomenon associated with a number of psychiatric conditions including schizophrenia and bipolar disorder. Early identification and prompt intervention to relieve the symptoms of agitation are essential to avoid symptomatic escalation and emergence of aggressive behaviour. Recent consensus guidelines emphasise the need for non-coercive management strategies to protect the therapeutic alliance between patients and their healthcare providers-an alliance that is critical for the effective management of chronic psychiatric conditions. Rapid symptom relief and de-escalation of agitation are necessary to avoid the costly and traumatic use of coercive techniques of physical restraint and seclusion, which require admission and prolonged hospitalisation. Inhaled loxapine is approved for the treatment of acute agitation in patients with schizophrenia or bipolar disorder. Clinical studies have confirmed the efficacy, rapid onset of action, and safety and tolerability of this agent in the psychiatric emergency and hospital settings. Emerging data have indicated the potential for inhaled loxapine as a self-administered agent for use in the community setting without the direct supervision of a healthcare professional. We discuss the evolving treatment paradigm and the place of inhaled medications for acutely agitated patients both within and outside the emergency and hospital setting.