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Real-world patient characteristics, treatment patterns, efficacy and safety of intramuscular ketamine treatment: a retrospective cohort study

Sachin Ahuja, Madeline Brendle, Leo Smart, Claire Moore, Paul Thielking, Reid Robison

Research Square February 14, 2022 preprint DOI: 10.21203/rs.3.rs-1331173/v1 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Retrospective observational cohort study
Sample size 452
Population Adults receiving intramuscular ketamine treatment at a private outpatient psychiatric clinic network in the United States
Intervention Ketamine
Duration Treatment period January 2018 to June 2021; maintenance improvements followed over 13 months
Measures PHQ-9, GAD-7
Topics Esketamine Ketamine
Citations 2
Key findings Average depression and anxiety symptoms improved by 34% each from baseline to last IM ketamine treatment, and with maintenance treatments median improvements of at least 21% (depression) and 19% (anxiety) were maintained for over 13 months. Adverse events occurred during 2.3% of treatments (59 of 2,532). The authors conclude IM ketamine is being used for outpatients with multiple, moderate-to-severe psychiatric diagnoses and recommend prospective studies to confirm long-term efficacy and safety.

Abstract

Abstract Background Ketamine has emerged as a promising pharmacotherapy for depression and other mental illnesses, and the intramuscular (IM) administration of ketamine is now offered at many North American outpatient psychiatric clinics. However, a characterization of the outpatient population receiving IM ketamine treatment, and an evaluation of the real-world efficacy and safety of long-term IM ketamine treatment, has not been reported. This study aimed to evaluate the clinical characteristics, treatment patterns, clinical outcomes, and adverse events of patients receiving IM ketamine treatment.Methods Patient data from the electronic health records of a private outpatient psychiatric clinic network in the United States were collected and analyzed retrospectively. Adults who received ketamine treatment only by IM administration from January 2018 to June 2021 were included; a total of 452 patients were included in the cohort.Results Patients receiving IM ketamine treatment had a mean of 2.8 (SD 1.4) psychiatric diagnoses. 420 (93%) patients had a diagnosis of major depressive disorder, 243 (54%) patients had a diagnosis of generalized anxiety disorder, and 126 (28%) patients had a diagnosis of post-traumatic stress disorder. Thirty-seven percent (42/114) of patients reported a history of a previous suicide attempt, and patients had an average of 3.1 (SD 2.9) psychiatric medication prescriptions at baseline. Patients received between 1 and 48 IM ketamine treatments. Average depression and anxiety symptoms both significantly improved by 34% (p < .001) from baseline (PHQ-9: mean=16.3, SD=6.7; GAD-7: mean=12.8, SD=5.7) to patients’ last treatment (PHQ-9: mean=10.8, SD=5.9; GAD-7: mean=8.4, SD=5.5), and suicidal ideation scores also significantly improved (p < .001) . With maintenance ketamine treatments, median improvements in depression and anxiety of at least 21% and 19% were maintained for over 13 months. An adverse event occurred during 59 of 2,532 treatments (2.3%).Conclusions IM ketamine is being utilized to treat psychiatric outpatients with a moderate-to-severe mental health history and multiple mental illnesses not limited to depression. Average depression and anxiety levels significantly improve throughout IM ketamine treatment and do not regress to baseline for over one year with maintenance treatments. Prospective studies are recommended to confirm the long-term efficacy and safety of IM ketamine.

Comparable studies

Other observational and cohort studies on ketamine, most cited first.

Study Year Design Participants
Taming the Ketamine Tiger Volunteers from a prison population 2010 Observational study n = 20
Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin Humans 2017 Observational study
Disruption of Frontal–Parietal Communication by Ketamine, Propofol, and Sevoflurane Surgical patients undergoing induction of anesthesia with intravenous ketamine 2013 Observational cohort n = 30
Do the dissociative side effects of ketamine mediate its antidepressant effects? Treatment-resistant inpatients with major depressive disorder or bipolar disorder 2014 Observational cohort n = 108
Concomitant BDNF and sleep slow wave changes indicate ketamine-induced plasticity in major depressive disorder Patients with treatment-resistant major depressive disorder 2012 Observational cohort n = 30

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