Serotonergic Anxiolytics in the Treatment of Panic Disorder: A Controlled Study With Buspirone

Abstract

The efficacy of buspirone for panic disorder was tested in 60 patients who met Diagnostic and Statistical Manual of Mental Disorders (3rd ed.) criteria for panic disorder or agoraphobia with panic attacks. Patients were randomly assigned to treatment with buspirone (mean dose 29.5 mg/day), imipramine (mean dose 140 mg/day), or placebo, and treated for 8 weeks after a 4- to 7-day placebo lead-in period. Patients with 4 or fewer attacks per month and those without attacks at the baseline visit were excluded from panic frequency comparisons. Both buspirone and imipramine tended to be better than placebo on total number of panic attacks, global psychopathology, and the Hamilton Anxiety rating scale, but end point differences among treatments were not statistically significant. At the end of the study, 25% of the buspirone patients were panic-free, as were 7% of the imipramine patients and 14% of the placebo patients; again, these differences were not statistically significant. The results of this study were inconclusive, partly because of the relatively small number of patients (10–11) completing the study in each treatment group, and partly because of a robust placebo response in this population. Possible reasons for this high placebo response are discussed, as well as suggestions for changes in study design for future studies.

The Mouse Defense Test Battery: pharmacological and behavioral assays for anxiety and panic

“…Although 5-HT 1A receptor agonists have no myorelaxant or ataxic effects, the severe reduction in activity seen in the pretest may be indicative of the appearance of the 5-HT syndrome, described in detail in subsequent studies using the runway apparatus (Blanchard et al, 1997a). Based on the idea that flight may model certain aspect of a panic attack, the failure of 5-HT 1A receptor agonists to modify this defensive reaction is not unexpected since human studies provide undisputed evidence of a lack of efficacy of such agents in panic reactions (Pecknold et al, 1993;Pohl et al, 1989;Sheehan et al, 1990;Van Vliet et al, 1996;Westenberg et al, 1992). Despite their clear effects on defensive aggression, a behavior proposed to reflect affective oriented aspects of generalized anxiety disorder, it is intriguing and puzzling that 5-HT 1A receptor agonists did not affect the highly benzodiazepine-sensitive risk assessment measure during the chase test.…”

Mouse defensive behaviors: pharmacological and behavioral assays for anxiety and panic

“…For example, although 5-HT1A receptor full and partial agonists (i.e. esinoxan, buspirone, ipsapirone) potently reduced ultrasound emission, clinical reports invariably failed to show an antipanic ef®cacy of these compounds [81,92,105]. Instead, panic may even be exacerbated by buspirone or esinoxan [23,42,74,102].…”

Advances in the Management of Treatment-Resistant Anxiety Disorders

“…Randomized double-blind placebo-controlled trials have found buspirone to be comparable to placebo and less effective than imipramine (Nϭ52) (53) and alprazolam (Nϭ92) (54). Another RCT (Nϭ60) detected no difference between buspirone, imipramine, or placebo groups (55), which the authors attributed in part to a strong placebo response. A small (Nϭ16) randomized study concluded that clorazepate was significantly more effective than buspirone (56).…”