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Repeated subcutaneous racemic ketamine in treatment-resistant depression: case series

Joseph C.W. Tham, André Do, Jason Fridfinnson, Reza Rafizadeh, Jacky T.P. Siu, George P. Budd, Raymond W. Lam

International Clinical Psychopharmacology September 1, 2022 DOI: 10.1097/yic.0000000000000409 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Clinical protocol with case series Case report Peer reviewed
Sample size 10
Population Inpatients with treatment-resistant depression
Intervention Subcutaneous racemic ketamine
Duration Maximum six treatments, twice per week
Measures Montgomery–Åsberg Depression Rating Scale (MADRS), Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR16)
Topics Depression Esketamine Ketamine
Key findings Repeated subcutaneous racemic ketamine relieved treatment-resistant depression symptoms in a small inpatient series: 8/10 responded and 8/10 remitted on the MADRS, while 6/10 responded and 5/10 remitted on the QIDS-SR16. Side effects were transient blood pressure changes and dissociation. The authors propose subcutaneous ketamine as a safe, feasible, and effective alternative to intravenous infusions.

Abstract

Interest in the use of parenteral ketamine has been increasing over the last 2 decades for the management of treatment-resistant depression (TRD). While intravenous (IV) ketamine has been the most common parenteral route of administration, subcutaneous (SC) and intramuscular options have been described. We developed a clinical treatment protocol for the use of repeated SC racemic ketamine (maximum six treatments, twice per week) in an inpatient psychiatric care setting with inclusion/exclusion criteria, dosing schedule, and description of treatment, assessment, and monitoring procedures. Results from the first 10 consecutive patients demonstrated the effectiveness of SC racemic ketamine in relieving symptoms of TRD as measured by the Montgomery–Åsberg Depression Rating Scale (MADRS) and Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR16). Response (≥50% reduction in scores from baseline to endpoint) was achieved in 8/10 cases on the MADRS and 6/10 on the QIDS-SR16. Remission was achieved in 8/10 (based on MADRS ≤10) and 5/10 (based on QIDS-SR16 ≤6). Patients tolerated the treatments well with only transient blood pressure changes and dissociative side effects. Repeated SC ketamine treatments could be a safe, feasible, and effective alternative to IV ketamine infusions for patients with TRD.

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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