Repeated intravenous infusions of esketamine in inpatients with bipolar depression: A retrospective real-world study

Abstract

Background

Ketamine shows promise for treating bipolar depression, particularly in severe cases. However, the optimal administration route and enantiomer (esketamine, arketamine, or racemic mixture) remain unclear. This case series presents data on intravenous (IV) esketamine in bipolar depression, addressing a gap in published literature.

Methods

This retrospective chart review included adult inpatients with bipolar depression treated with multiple IV esketamine infusions. Outcomes were measured using the self-rated Montgomery Åsberg Depression Scale (MADRS-S) and clinician-rated improved Global Clinical Impression Scale-Severity Index (rCGI-S). Tolerability data were also collected.

Results

Thirteen patients received 4–6 IV esketamine infusions over two weeks. Statistically significant improvements were observed in MADRS-S total scores (p = 0.002) and rCGI-S scores (p < 0.001) but not in MADRS-S suicidal thoughts item (p = 0.125). Infusions were generally well-tolerated, with treatment-emergent hypomania in two patients (15.4 %).

Limitations

The retrospective design without a control group limited effectiveness evaluation.

Conclusions

Preliminary results of IV esketamine for bipolar depression are promising, but its role in treatment algorithms requires clarification. Randomized controlled studies are needed to investigate its effectiveness further.