Combined Paroxetine and Clonazepam Treatment Strategies Compared to Paroxetine Monotherapy for Panic Disorder

Abstract

Despite the widespread application of combined selective serotonin reuptake inhibitors (SSRI) and benzodiazepine treatment for panic disorder, there has been relatively little systematic assessment of the safety and efficacy of this therapeutic strategy. Although the limited number of studies to date suggest a more rapid onset of benefit with combined treatment, this study is the first to address the critical question of whether continued combined treatment confers superior efficacy. This study is a randomized, double-blind, three-arm study in patients with panic disorder (n = 60), comparing the efficacy and safety of paroxetine and placebo (PP), paroxetine coadministered with clonazepam followed by a tapered benzodiazepine discontinuation phase (PC-D), and ongoing combination treatment (PC-M). All treatment groups demonstrated significant improvement by endpoint. There was a significant advantage for the combined treatment groups early in treatment but, subsequently, outcome in all three groups was similar. A trend towards greater achievement of endpoint remission status for the PC-D group was attenuated when variability in baseline severity was considered. The results of this study should be interpreted in the context of a relatively moderate sample size and higher rates of early dropout. Combined treatment with paroxetine and clonazepam resulted in more rapid response than with the SSRI alone, but there was no differential benefit beyond the initial few weeks of therapy. Initiating combined treatment followed by benzodiazepine taper after a few weeks may provide early benefit while avoiding the potential adverse consequences of long-term combination therapy.