784. A Retrospective Report of Efficacy and Tolerability of Low Daily Dose Ketamine for Depression and Anxiety in a Large Population Sample

Abstract Background Use of intravenous ketamine or intranasal esketamine for depression is frequently limited due to resource requirements and cost. Alternative treatment models have used oral, sublingual or intranasal racemic ketamine, but optimal doses and frequency of administration remain unclear. Dosing modelled from the standard 0.5-1.0mg/kg twice weekly IV ketamine result in transient dissociative effects and render potential concern for psychological safety if used outside of a healthcare setting. Very limited previous data have suggested potential efficacy of lower, non dissociative doses, which would be better suited to home use. Joyous, a United States based company, has now treated over 50,000 patients with this model, using low daily dose buccal ketamine for home use, and collected patient data regarding outcomes and tolerability. Aims & Objectives Data from charts of adult patients who participated in the Joyous treatment program were retrospectively reviewed to evaluate efficacy and tolerability of low daily dose ketamine for treatment of mood and anxiety symptoms over an acute 4 week treatment period. In particular we aimed to assess 1) change in depression and anxiety scores over time, which were measured by the Patient Health Questionnaire - 9 item (PHQ9) and Generalized Anxiety Disorder-7 item scale (GAD 7), 2) response and remission rates for depression and anxiety, 3) drop out rates, and 4) reporting of serious side effects.

Method: Data collected routinely from adult patients receiving lower dose buccal ketamine through the Joyous program were analysed. Raw PHQ9 and GAD7 scores, response/remission rates, and dropout rates at 4 weeks were evaluated in participants with a baseline >9 for each scale.

Results: The sample consisted of 59759 participants (46.2%M) with baseline mean scores of PHQ9 =13.8 (5.2) and GAD7=12.8 (5.3). 4 week outcomes for depression and anxiety were evaluated in participants with a baseline >9, indicating at least moderate symptom severity. The depression group consisted of 44352 participants with a baseline PHQ9 =16.4 (4.2). By week 4, 30413 participants remained and mean PHQ9 demonstrated a reduction to 7.7 (4.9). Response and remission rates were 63.4% and 29.6% respectively. In the 42353 participants in the anxiety group, baseline mean GAD7 was 15.5 (5.4), and reduced to 7.7 (4.9) at week 4 in the 28996 remaining participants. At week 4, response and remission in the anxiety group was 63.4% and 31.7% respectively. Mean dose in all program participants at day 7 was 45 mg and 70 mg at day 28 . Dropout rates at week 4 were 31.4% in the mood group and 31.5% in the anxiety group, but no patient endorsed “intolerable” side effects within these 28 days of treatment. Though only a small portion of patients provided reason for discontinuation, the most reported was lack of efficacy. Discussion & Conclusions Lower dose daily buccal ketamine demonstrated significant reductions in depression and anxiety symptoms over 4 weeks. Further analysis is required to account for participant dropout, and to evaluate for longer term efficacy, safety, and tolerability.