Emerging drugs for panic disorder.

INTRODUCTION: Panic disorder (PD) is a common anxiety disorder impairing strongly quality of life with high social costs. Effective anti-panic medications exist but a substantial proportion of patients do not fully respond, the available drugs have several side effects and most medications have a delayed onset of their therapeutic effect. Thus, further advances are needed. AREAS COVERED: We review available data on emerging drugs for the treatment of PD including those in development, such as metabotropic glutamate II receptor agonists, D-cycloserine and levetiracetam, and new compounds with potential efficacy that may be relevant for future developments, such as modulators of cholinergic and orexin systems. EXPERT OPINION: To date, the pharmacological research on PD appears to be relatively limited and probably still needs more time before making available new advances beyond the currently used medications. Many reasons may explain these difficulties, including the heterogeneity of the disorder, the incomplete understanding of its underlying pathophysiological mechanisms and difficulties in the selection of appropriate animal models in preclinical studies. Defining biomarkers and endophenotypes in PD may offer advantages in both understanding the pathophysiology of the disorder and selecting appropriate targets and outcomes for planning future pharmacological research.