AIMS: Ketamine has been shown to decrease suicidality in patients with depression. However, little is known about tolerability and efficacy in heterogenous, acutely suicidal patients in emergency settings. This pilot study aimed to assess the feasibility, acceptability, and safety of generic intranasal racemic ketamine (75 mg) in the treatment of acute suicidality regardless of the underlying diagnosis, as preparation for a subsequent double-blind randomized placebo-controlled trial (RCT).
METHOD: From September 2021 to June 2022, 12 patients with acute suicidality were recruited. All received a single open-label dose of 75 mg intranasal racemic ketamine. Suicidality was assessed with the Beck Scale for Suicidal Ideation (BSSI), depression with the Montgomery-Åsberg Depression Rating Scale (MADRS), side effects with the Systematic Assessment for Treatment Emergent Effects (SAFTEE) and Clinician Administered Dissociative Symptom Scale (CADSS), and overall improvement with the Clinical Global Impression (CGI) at 60 min, 180 min, and at 1, 3, and 7 days post-treatment. The CADSS and SAFTEE were administered only at baseline, 60 and 180 min post intervention. Vital signs were monitored for the first 240 min post intervention. Optional blood sampling occurred at baseline and 180 min post-treatment, and Magnetic Resonance Imaging one day post intervention.
RESULTS: Treatment was well-tolerated. We observed a downward trend in both BSSI and MADRS scores one day post treatment, though this effect declined by day seven. One patient developed ketamine misuse several weeks after participation.
CONCLUSIONS: The treatment was generally feasible, well-tolerated and safe. Intranasal ketamine reduced acute suicidality in some cases but regarding efficacy, no definitive conclusions can be drawn from this pilot study. Amendments were made to the study protocol with extended follow-up time, investigation of drug liking and craving, less questionnaires and longer inclusion window.
