Inhaled loxapine for acute agitation in schizophrenia and bipolar disorder

Pharmacological treatment of acute agitation associated with psychotic and bipolar disorder: a systematic review and meta-analysis

OBJECTIVES

We used systematic review methodology to identify and evaluate short-term pharmacological interventions for agitation associated with schizophrenia or bipolar disorder.

METHOD

We searched electronic databases for randomised controlled trials involving comparisons between current treatments for agitation, benzodiazepines, antipsychotics and placebo. The patient population was adults with agitation associated with psychotic or bipolar disorder treated in specialist mental health services. The outcome of interest was change in agitation measured by accepted standard scales. Paired meta-analyses and network meta-analyses are presented.

RESULTS

Seventeen randomised controlled trials were identified (n = 3841). Treatments included haloperidol, olanzapine, aripiprazole, risperidone and lorazepam. The primary outcome was change in Positive and Negative Syndrome Scale Excited Component scores. Pair-wise comparisons suggest that after 60 min, olanzapine is superior to haloperidol; no other treatment was more effective than any other. At 120 min, loxapine 10 mg is more effective than loxapine 5 mg, and olanzapine is more effective than lorazepam. In the network meta-analyses, no treatment was superior to any other.

CONCLUSION

Because of limitations of available research, firm conclusions could not be drawn regarding the efficacy and safety of any identified intervention. Based on our results, there is no evidence that one drug is more effective or preferred over any other and treatment decisions could be made based on individual patient needs or costs. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Safety and efficacy review of inhaled loxapine for treatment of agitation

Agitation is common in patients with acute schizophrenia and bipolar disorder, and rapid and effective treatment of acute agitation is an important clinical goal. Loxapine is a first-generation antipsychotic medication available in the United States in oral form for more than three decades. In December 2012, an inhaled version of vaporized loxapine was approved by the U.S. FDA for the treatment of agitated adults in the context of schizophrenia or bipolar disorder. In this review, we examine available literature to describe efficacy and safety of inhaled loxapine in healthy patients and in those with pulmonary compromise. Limitations of the current evidence base to predict efficacy in "real world" patients are described, and safeguards necessary for appropriate use in psychiatric acute care settings are discussed.

Pulmonary delivery of therapeutic compounds for treating CNS disorders

Delivering therapeutic compounds via the lungs presents potential advantages relative to other routes of administration. Depending on the compound and the disease state, these advantages may include: non-invasive medication delivery, ease of administration, higher bioavailability leading to dose sparing and lower systemic toxicity, potentially greater blood–brain barrier penetration and rapid pharmacodynamic effect. The practice of inhaling drugs has been around for centuries, including both medical and recreational usage. It is only more recently that formal clinical development programs have been undertaken specifically to use medication delivery via the lung to achieve systemic blood levels for the treatment of CNS disorders. At present, there are several CNS therapies being developed for pulmonary administration, with some of those programs at or near the marketing authorization stage. While there are still regulatory hurdles before these therapies can be put into practice, the success of these programs thus far demonstrates the scientific viability of inhalation therapies for treating CNS disorders.

Aerosolised antipsychotic assuages agitation: inhaled loxapine for agitation associated with schizophrenia or bipolar disorder

OBJECTIVE

To describe the efficacy and safety of inhaled loxapine, a new formulation of an older antipsychotic being developed for the treatment of agitation associated with schizophrenia or bipolar disorder.

DATA SOURCES

A literature search was conducted by querying http://www.pubmed.gov, http://www.fda.gov, http://www.accessdata.fda.gov/scripts/cder/drugsatfda and http://www.clinicaltrials.gov for the search terms 'loxapine' AND 'agitation', 'inhaled loxapine', 'staccato loxapine'. The manufacturer was asked to provide copies of posters presented at national and international meetings, and to provide any copies of papers currently in press.

STUDY SELECTION

All available reports of studies were identified.

DATA EXTRACTION

Descriptions of the principal results and calculation of number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the study reports.

DATA SYNTHESIS

Inhaled loxapine is delivered using a handheld device that produces a thermally generated condensation aerosol free of excipients or propellants. Time to maximum plasma concentration is approximately 2 min. In two phase III studies (one in subjects with schizophrenia, the other in subjects with bipolar disorder) inhaled loxapine 5 and 10 mg were both superior to placebo as early as 10 min after administration, as measured using the Positive and Negative Syndrome Scale excited component. Pooling together data from three efficacy studies, NNT for response for inhaled loxapine 5 or 10 mg vs. placebo were 4 (95% CI 3-5) and 3 (95% CI 3-4), respectively, with response defined as achieving a Clinical Global Impressions - Improvement score of 1 or 2 at 2 h postdose. This effect size is in the range observed for intramuscular administration of other antipsychotics for agitation associated with schizophrenia or bipolar disorder. There were no clinically relevant signals for the emergence of extra-pyramidal side effects or akathisia. The most commonly encountered adverse event appears to be dysgeusia (distorted taste sense or bad taste), with a NNH vs. placebo of 10 (95% CI 7-22) or 12 (95% CI 8-26), for loxapine 10 or 5 mg, respectively.

CONCLUSIONS

Inhaled loxapine appears efficacious and tolerable for the treatment of agitation associated with schizophrenia or bipolar disorder. Although simple to self-administer, inhaled loxapine requires a degree of cooperation from the recipient and thus will not be a substitute for an injection during psychiatric emergencies when the patient is actively refusing medication treatment. The efficacy and safety of inhaled loxapine in elderly patients and in outpatient care settings remain to be established.