A double-blind, randomized, placebo-controlled trial of pindolol augmentation in depressive patients resistant to serotonin reuptake inhibitors

Abstract

[Background] Pindolol has been reported to hasten the antidepressant action of selective serotonin reuptake inhibitors in open-label and placebo-controlled trials. Pilot studies also suggested that pindolol could augment the antidepressant response in unresponsive patients. We investigated whether the addition of pindolol can induce a rapid response in treatment-resistant patients.

[Methods] After a single-blind lead-in placebo phase of 5 days to exclude placebo responders, 80 outpatients with major depression who did not respond to a minimum of 6 weeks of treatment with clomipramine hydrochloride, 150 mg/d; fluoxetine hydrochloride, 40 mg/d; fluvoxamine maleate, 200 mg/d; or paroxetine hydrochloride, 40 mg/d, were randomly assigned to additionally receive placebo (3 times daily) or pindolol (2.5 mg 3 times daily) for 10 days. The median number of ineffective treatments in the current episode was 2 (range, 1-4). Hamilton Rating Scale for Depression and Montgomery-Asberg Scale for Depression scores were used as primary measures of efficacy.

[Results] At end point, the Hamilton and Montgomery-Asberg scores and change from baseline in Hamilton score were not significantly different in patients taking placebo or pindolol. The response rate was equal in both groups (12.5%). No differences in the clinical outcome were found when the various pretreatment subgroups were considered. At end point, the plasma concentration of pindolol was 9.9+/-5.1 ng/mL (mean +/- SD; n = 40).

[Conclusions] Although pindolol can accelerate the antidepressant action of selective serotonin reuptake inhibitors in previously untreated patients, it does not elicit a rapid clinical response in treatment-resistant patients within a 10-day period.