Safety and efficacy review of inhaled loxapine for treatment of agitation

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.

Recent advances in drug delivery to the central nervous system by inhalation

INTRODUCTION

Drugs need to enter the systemic circulation efficiently before they can cross the blood-brain barrier and reach the central nervous system. Although the respiratory tract is not a common route of administration for delivering drugs to the central nervous system, it has attracted increasing interest in recent years for this purpose.

AREAS COVERED

In this article, we compare pulmonary delivery to three other common routes (parenteral, oral, and intranasal) for delivering drugs to the central nervous system, followed by summarising the devices used to aerosolise neurological drugs. Recent studies delivering drugs for different neurological disorders via inhalation are then discussed to illustrate the strengths of pulmonary delivery.

EXPERT OPINION

Recent studies provide strong evidence and rationale to support inhaling neurological drugs. Since inhalation can achieve improved pharmacokinetics and rapid onset of action for multiple drugs, it is a non-invasive and efficient method to deliver drugs to the central nervous system. Future research should focus on delivering other small and macro-molecules via the lungs for different neurological conditions.

Organic Solution Advanced Spray-Dried Microparticulate/Nanoparticulate Dry Powders of Lactomorphin for Respiratory Delivery: Physicochemical Characterization, In Vitro Aerosol Dispersion, and Cellular Studies

The purpose of this study was to formulate Lactomorphin (MMP2200) in its pure state as spray-dried(SD) powders, and with the excipient Trehalose as co-spray-dried(co-SD) powders; for intranasal and deep lung administration with Dry Powder Inhalers (DPI). Lactomorphin is a glycopeptide which was developed for the control of moderate to severe pain. Particles were rationally designed and produced by advanced spray drying particle engineering in a closed mode from a dilute organic solution. Comprehensive physicochemical characterization using different analytical techniques was carried out to analyze the particle size, particle morphology, particle surface morphology, solid-state transitions, crystallinity/non-crystallinity, and residual water content. The particle chemical composition was confirmed using attenuated total reflectance-Fourier-transform infrared (ATR-FTIR), and Confocal Raman Microscopy (CRM) confirmed the particles' chemical homogeneity. The solubility and Partition coefficient (LogP) of Lactomorphin were determined by the analytical and computational methodology and revealed the hydrophilicity of Lactomorphin. A thermal degradation study was performed by exposing samples of solid-state Lactomorphin to a high temperature (62 °C) combined with zero relative humidity (RH) and to a high temperature (62 °C) combined with a high RH (75%) to evaluate the stability of Lactomorphin under these two different conditions. The solid-state processed particles exhibited excellent aerosol dispersion performance with an FDA-approved human DPI device to reach lower airways. The cell viability resazurin assay showed that Lactomorphin is safe up to 1000 μg/mL on nasal epithelium cells, lung cells, endothelial, and astrocyte brain cells.

Therapeutic options for agitation in the intensive care unit

Agitation is common in the intensive care unit (ICU). There are numerous contributing factors, including pain, underlying disease, withdrawal syndrome, delirium and some medication. Agitation can compromise patient safety through accidental removal of tubes and catheters, prolong the duration of stay in the ICU, and may be related to various complications. This review aims to analyse evidence-based medical literature to improve management of agitation and to consider pharmacological strategies. The non-pharmacological approach is considered to reduce the risk of agitation. Pharmacological treatment of agitated patients is detailed and is based on a judicious choice of neuroleptics, benzodiazepines and α2 agonists, and on whether a withdrawal syndrome is identified. Specific management of agitation in elderly patients, brain-injured patients and patients with sleep deprivation are also discussed. This review proposes a practical approach for managing agitation in the ICU.

The Gut Microbiome and Treatment-Resistance in Schizophrenia

The effect of antipsychotic medication is poor in 30-40% of patients with schizophrenia; treatment resistance is usually met with shifts to new drugs or drug augmentation strategies or a trial of clozapine. The purpose of this review was to examine the potential role of intestinal bacteria in the bioavailability of antipsychotic medication and the possibility that parenterally administered antipsychotics might be able to overcome treatment resistance. Databases were searched with appropriate terms to locate relevant papers dealing with the effect of antipsychotic drugs on the gut microbiome and the effect of bacterial metabolizing enzymes on antipsychotic drugs. Also searched were papers addressing the various current parenteral formulations of antipsychotic drugs. Sixty-five recent pertinent papers were reviewed and the results are suggestive of the premise that there is a drug refractory form of psychosis for which the composition of gut bacteria is responsible, and that parenteral drug administration could overcome the problem.

Examining the safety, efficacy, and patient acceptability of inhaled loxapine for the acute treatment of agitation associated with schizophrenia or bipolar I disorder in adults

Agitation is a common and serious symptom of bipolar mania and schizophrenia, and can be defined as excessive motor and verbal activity. If left unrecognized and untreated, agitation can evolve into aggression, resulting in potential patient and staff injury. An ideal treatment for agitation would have a rapid onset, cause calmness without sedation, and be tolerable, efficacious, and non-coercive, while managing the underlying condition. A novel approach for the treatment of agitation is inhaled loxapine. Inhaled loxapine is rapidly absorbed into the systemic circulation through the alveoli, resulting in a near immediate onset of action. The efficacy of inhaled loxapine was established in an extensive clinical development program that included persons with schizophrenia and bipolar mania. Additionally, inhaled loxapine has comparable efficacy to intramuscular ziprasidone, olanzapine, haloperidol, aripiprazole, and lorazepam, with the added benefit of being non-painful and non-traumatizing. Inhaled loxapine carries a bolded black box warning for bronchospasm, and as a result, in the US, requires enrollment in a Risk Evaluation and Mitigation Strategy program, and is contraindicated in those with pulmonary disease. Additionally, the use of inhaled loxapine can be associated with dysgeusia and throat irritation. Inhaled loxapine requires some degree of patient cooperation, and therefore may not be appropriate for all agitated patients.

A Modern-Day Fight Club? The Stabilization and Management of Acutely Agitated Patients in the Emergency Department

This article is an overview of the treatment and management of acutely agitated patients as they present in the emergency department or emergency psychiatric facility. This article focuses on how a patient encounter may unfold and what issues need to be considered along the way. Verbal de-escalation is emphasized as a standard of care, including the offering of environmental changes and medications when indicated. Approved medications are reviewed as well as the proper use of restraints.

Inhaled loxapine and intramuscular lorazepam in healthy volunteers: a randomized placebo-controlled drug-drug interaction study

Pharmacodynamic effects and safety of single‐dose inhaled loxapine administered via the Staccato^® system and intramuscular (IM) lorazepam in combination versus each agent alone were compared in a randomized, double‐blind, crossover study in healthy volunteers. Subjects received: inhaled loxapine 10 mg + IM lorazepam 1 mg; inhaled loxapine 10 mg + IM placebo; IM lorazepam 1 mg + Staccato placebo in random order, each separated by a 3‐day washout. Primary endpoints were maximum effect (minimum value) and area under the curve (AUC) from baseline to 2 h post treatment for respirations/min and pulse oximetry. Least‐squares means (90% confidence interval [CI]) for concomitant treatment versus each agent alone were derived and equivalence (no difference) confirmed if the 90% CI was within 0.8–1.25. Blood pressure (BP), heart rate (HR), sedation (100‐mm visual analog scale), and adverse events (AEs) were recorded. All 18 subjects (mean age, 20.4 years; 61% male) completed the study. There was no difference between inhaled loxapine + IM lorazepam and either agent alone on respiration or pulse oximetery during the 12‐h postdose period, confirmed by 90% CIs for AUC and C_min ratios. BP and HR were no different for inhaled loxapine + IM lorazepam and each agent alone over a 12‐h postdose period. Although the central nervous system sedative effects were observed for each treatment in healthy volunteers, the effect was greater following concomitant lorazepam 1 mg IM + inhaled loxapine 10 mg administration. There were no deaths, serious AEs, premature discontinuations due to AEs, or treatment‐related AEs.

Inpatient aggression in community hospitals

Physical violence is a frequent occurrence in acute community psychiatry units worldwide. Violent acts by patients cause many direct injuries and significantly degrade quality of care. The most accurate tools for predicting near-term violence on acute units rely on current clinical features rather than demographic risk factors. The efficacy of risk assessment strategies to lower incidence of violence on acute units is unknown. A range of behavioral and psychopharmacologic treatments have been shown to reduce violence among psychiatric inpatients.

The role of long-acting injectable antipsychotics in schizophrenia: a critical appraisal

Despite their widespread use, long-acting injectable (LAI) antipsychotics (APs) are often regarded with some negativity because of the assumption of punishment, control and insufficient evolution towards psychosocial development of patients. However, LAI APs have proved effective in schizophrenia and other severe psychotic disorders because they assure stable blood levels, leading to a reduction of the risk of relapse. Therapeutic opportunities have also arisen after introduction of newer, second-generation LAI APs in recent years. Newer LAI APs are more readily dosed optimally, may be better tolerated and are better suited to integrated rehabilitation programmes. This review outlines the older and newer LAI APs available for the treatment of schizophrenia, with considerations of past and present pharmacological and therapeutic issues. Traditional, evidence-based approaches to systematic reviews and randomized clinical trials are of limited utility in this area so this paper's blending of experimental trials with observational research is particularly appropriate and effective.

Management of psychosis and agitation in medical-surgical patients who have or are at risk for prolonged QT interval

We review the literature on management of psychosis and agitation in medical-surgical patients who have or are at risk for prolonged QT interval, a risk factor for torsade de pointes (TdP), and we describe our protocols for treating these patients. We searched PubMed and PsycInfo for relevant studies and found few papers describing options for treating psychosis and agitation in these patients. Prolonged QTc interval has been more often associated with low-potency phenothiazines such as thioridazine; however, it may occur with high potency typical antipsychotics such as fluphenazine and haloperidol as well as with atypical antipsychotics such as quetiapine, risperidone, olanzapine, iloperidone, and particularly ziprasidone. Antipsychotics for which no association with prolonged QTc interval has been shown include lurasidone, clozapine, and aripiprazole. For patients who have risk factors for prolonged QTc interval but whose electrocardiograms do not show this, reasonable first choices include oral or intramuscular olanzapine or aripiprazole, followed by risperidone and quetiapine or oral or intramuscular haloperidol. For those who have prolonged QTc but that measures less than 500 ms, we limit the use of antipsychotics to aripiprazole, olanzapine, risperidone, or quetiapine. Finally, for patients who have a QTc of 500 ms or greater, we rely on aripiprazole, valproate, trazodone, and benzodiazepines.

Advances in device and formulation technologies for pulmonary drug delivery

Inhaled pharmaceuticals are formulated and delivered differently according to the therapeutic indication. However, specific device-formulation coupling is often fickle, and new medications or indications also demand new strategies. The discontinuation of chlorofluorocarbon propellants has seen replacement of older metered dose inhalers with dry powder inhaler formulations. High-dose dry powder inhalers are increasingly seen as an alternative dosage form for nebulised medications. In other cases, new medications have completely bypassed conventional inhalers and been formulated for use with unique inhalers such as the Staccato® device. Among these different devices, integration of software and electronic assistance has become a shared trend. This review covers recent device and formulation advances that are forming the current landscape of inhaled therapeutics.

Targeting inhaled therapy beyond the lungs

Pulmonary disease has been the primary target of inhaled therapeutics for over 50 years. During that period, increasing interest has arisen in the use of this route of administration to gain access to the systemic circulation for the treatment of a number of diseases beyond the airways. In order to effectively employ this route, the barriers to transport from the lungs following deposition of aerosols must be considered, including the nature of the disease (whether proximal, as in pulmonary hypertension, or distal, as in diabetes). Delivery to the systemic circulation begins with the efficiency of aerosol generation and subsequent deposition in the airways and proceeds to the influence of mechanisms of clearance, including absorption, metabolism, and mucociliary and cell-mediated transport, on the residence time of the drugs in the lungs. The nature of the drug (small or large molecules/low or high molecular weight), susceptibility to degradation and general physicochemical properties play a role in the chemistry of its formulation, physics of aerosol delivery and biology of disposition.