Beneficial effect of digoxin-specific Fab fragments in bipolar disorder- a preliminary study

Background: A vast amount of experimental data supports the notion that Na⁺, K⁺-ATPase and endogenous cardiac steroids (ECS) such as digoxin and ouabain are involved in bipolar disorders. The aim of the study was to examine the possible beneficial effect of Digoxin-specific antibody Fab fragments Digibind, in bipolar disorder (BD) patients. Methods: In a pilot, open-label study without a control group, BD inpatient subjects received a single dose of Digibind, injected intravenously. During the 72 hrs following the intervention. the response to Digibind was measured using the Montgomery-Asberg Depression Rating Scale (MADRS). Results: A total 6 patients with a moderate to severe bipolar depressive episode (MADRS 30.3, 24–38) participated in the study. We found a significant clinical improvement at all time points after Digibind administration, manifested by a maximal decrease in the MADRS score of 8.3 points at 24 hrs, followed by a gradual rebound to baseline scores. Limitations: No control group was included, treatment was open-label, and only 6 patients were studied. Conclusions: This preliminary study showed that a one-time injection of Digibind resulted in a transient significant beneficial effect on depression symptoms in BD patients.