Rapid infusion of esketamine for unipolar and bipolar depression: a retrospective chart review

Background: This study evaluated efficacy and safety of intravenous subanesthetic doses of esketamine using an administration time of 10 minutes in patients with treatment-resistant depression and bipolar depression. Methods: A retrospective chart review was conducted to identify patients who met the inclusion criteria for treatment-resistant depression and bipolar depression according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria, and these patients received rapid infusion of esketamine between June 2012 and December 2015. The Montgomery-angstrom sberg Depression Rating Scale (MADRS) was administered to measure and score depressive symptom severity before infusion and at 24 hours, 72 hours, and 7 days after infusion. In addition, Clinical Global Impression scale was administered before and 7 days after esketamine infusion. Results: Esketamine was administered to 30 patients. A total of 27 patients met the inclusion criteria and had MADRS evaluation data, which showed that 23 had unipolar and 4 had bipolar depression. Thirteen patients (48.1%) showed therapeutic response (MADRS reduction. 50%) within 1 week (7 days) of intervention. Remission (MADRS. 7) was observed in 10 patients (37.0%) in the same period. Therapeutic response and remission frequencies were seen in 16 (59.3%) and 11 (40.7%) patients, respectively, within 24 hours following drug infusion. The most relevant side effect observed during the esketamine infusion was dissociative symptoms ranging from mild to severe, which was reported by 11.1% of patients as a very disturbing experience. Limitations: This study was done retrospectively, had a small sample size, and there was no comparative group. Conclusion: The present study demonstrates that rapid infusion of esketamine is possibly not the optimal choice to administer this drug for treatment-resistant depression due to tolerability reasons. Further controlled studies are required to investigate efficacy, safety, and tolerability profiles among the different types of ketamines and methods of using this drug in depressed patients.