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Case Report: Repeated Series of Ketamine Infusions in Patients With Treatment-Resistant Depression: Presentation of Five Cases

Maria Gałuszko‐węgielnik, Adam Włodarczyk, Wiesław Jerzy Cubała, Alina Wilkowska, Natalia Górska, Jakub Słupski

Frontiers in Psychiatry December 2, 2021 DOI: 10.3389/fpsyt.2021.705190 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Case series Case report Peer reviewed
Sample size 5
Population Inpatients aged 43–63 with treatment-resistant depression in major depressive disorder or bipolar disorder type I
Intervention Intravenous ketamine
Duration Eight infusions per series; readministered due to worsening symptoms
Topics Depression Ketamine Esketamine
Keywords Depression economics Presentation obstetrics Series stratigraphy Anesthesia Surgery Mood
Citations 5
Key findings Repeated series of intravenous ketamine infusions as an add-on treatment led to remission in four of five patients after the first series and three after the second series, with mild and transient adverse events.

Abstract

Purpose: Approximately 30% of patients with major depressive disorder (MDD) are treatment resistant. There is an unquestionable need for new treatment strategies. Subanesthetic doses of intravenous (IV) ketamine have a rapid antidepressant effect in treatment-resistant depression (TRD). This paper describes the efficacy of repeated series of intravenous ketamine infusions as an add-on treatment in five TRD inpatients.

Methods: Eligible patients aged 43–63 were given eight ketamine infusions as an add-on treatment for patients with MDD. The subjects have readministered the intervention due to worsening depressive symptoms.

Results: Of the five inpatients given ketamine as a series of eight infusions, one underwent three, and four had two treatment series. Four patients achieved remission after first series and three after the second series of ketamine infusions. The adverse reactions were mild and transient with no sequelae.

Limitations: Presented case series applies to short-term intervention with IV ketamine as an add-on therapy. The results cannot be generalized to the long-term maintenance treatment nor other ketamine formulations as well as different administration schedules and dosing.

Conclusions: This case series showed efficacy and safety of the repeated series of IV ketamine treatment in TRD in MDD and bipolar disorder type I. The subsequent interventions were safe and observed adverse events were mild and transient. Interestingly, the IV ketamine treatment at successive administrations seems to alter the major depression severity of the next affective episode. There is a critical need for further research regarding IV ketamine treatment effectiveness and long-term safety in future studies.

Comparable studies

Other case reports and case series on ketamine for depression, most cited first.

Study Year Design Participants
Electroconvulsive Therapy, Ketamine, and Esketamine in a Patient with Major Depressive Disorder and Multiple Comorbidities: A Case Report over 10-year Treatment from Adolescence to Adulthood. A patient with treatment-resistant depression and comorbid generalized anxiety... 2025 Case report n = 1
A longitudinal case series of IM ketamine for patients with severe and enduring eating disorders and comorbid treatment‐resistant depression Patients with enduring eating disorders and treatment-resistant depression 2021 Case series n = 4
Effects of intranasal (S)-ketamine on Veterans with co-morbid treatment-resistant depression and PTSD: A retrospective case series Veterans with co-morbid depression and PTSD 2022 Retrospective case series n = 35
Case report: Intramuscular ketamine or intranasal esketamine as a treatment in four patients with major depressive disorder and comorbid anorexia nervosa Patients with anorexia nervosa and a comorbid depressive disorder treated at a private... 2023 Case report n = 4
Repeated oral esketamine in patients with treatment resistant depression and comorbid posttraumatic stress disorder Patients with treatment-resistant depression and comorbid PTSD 2023 Case series n = 5

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