Pindolol augmentation in patients with treatment-resistant panic disorder:A double-blind, placebo-controlled trial

The objective of this study was to determine the efficacy of pindolol as an augmentor of fluoxetine in treatment-resistant panic disorder (PD). Twenty -five outpatients having PD with or without agoraphobia were included. Thes e patients had not responded to two different trials with antidepressants a nd an 8-week trial of fluoxetine 20 mg/day. Treatment-resistant PD was defi ned as a less than 20% reduction in score on the Panic Self-questionnaire ( number of attacks per week) (PSQ) and the Clinical Anxiety Scale With Panic Attacks (CAS+ PA). These patients continued to receive fluoxetine 20 mg/da y and were randomly assigned to additionally receive either pindolol (2.5 m g three times daily) or placebo for the following 4 weeks. Evaluations were performed weekly using the Hamilton Rating Scale for Anxiety, the Hamilton Rating Scale for Depression (HAM-D), the CAS+PA, the NIMH Anxiety Scale, t he PSQ, and the Clinical Global Impression Scale. The data were analyzed us ing a repeated-measures analysis of variance (ANOVA) and a t-test for indep endent samples. Patients treated with the combination of pindolol and fluox etine (N = 13) demonstrated a significant improvement over the patients tre ated with fluoxetine and placebo on all rating scales, with the exception o f HAM-D. The statistical differences were shown using the repeated-measures ANOVA (baseline, week 2, week 4) and also with t-tests from the second wee k of the trial. These preliminary results demonstrate that pindolol has an augmenting effect on fluoxetine in patients with treatment-resistant PD.