Loxapine inhalation powder: a review of its use in the acute treatment of agitation in patients with bipolar disorder or schizophrenia

Loxapine is a well-established, first-generation antipsychotic agent. Loxapine inhalation powder (Adasuve(®)) was recently approved in the USA and the EU for use in the acute treatment of agitation in patients with bipolar disorder or schizophrenia. Inhaled loxapine is delivered by a hand-held, single-dose, single-use device that uses the Staccato(®) drug delivery system. With Adasuve(®), maximum plasma loxapine concentrations are reached in a median of 2 min. In two randomized, double-blind, placebo-controlled, multicentre trials, inhaled loxapine 5 or 10 mg significantly reduced agitation (assessed using Positive and Negative Syndrome Scale-Excited Component scores) in patients with bipolar I disorder or schizophrenia, with the onset of effect seen within 10 min of administration. Inhaled loxapine was generally well tolerated in phase III trials (which excluded patients with clinically significant acute or chronic pulmonary disease), with the most commonly occurring adverse events including dysgeusia and sedation. Inhaled loxapine is contraindicated in patients with airways disease associated with bronchospasm or acute respiratory signs or symptoms. In conclusion, inhaled loxapine provides a novel new option for use in the acute treatment of agitation in patients with bipolar disorder or schizophrenia, combining a rapid onset of effect with a noninvasive route of administration.