Open-label Prospective, Interventional Study Assessing Efficacy and Safety of Intramuscular Ketamine for Suicidal...

This study evaluated intramuscular (IM) ketamine's efficacy and safety for rapid suicidal ideation reduction, addressing the critical need for fast-acting interventions in resource-limited settings where intravenous (IV) options are impractical.

We conducted a pre-post-interventional study of IM ketamine (0.5 mg/kg) over one year after approval of the institutional ethics committee. Adult patients with suicidal ideation, as measured by the six-point Montgomery-Åsberg Depression Rating Scale-Suicidal Ideation (MADRS-SI), were included if their MADRS-SI score was >4. Post-injection monitoring of suicidal ideation and adverse effects (A/E) was done after two hours and on Days 1, 3, 7, 14, 21, and 28. A repeat injection of the same dose was given only if the MADRS-SI score became > 4 again. The paired-T-test and repeated-measure ANOVA test were used for statistical analysis.

Thirty-eight patients (mean age: 36.3 years) participated, with 66% diagnosed with major depressive disorder and a mean MADRS-SI score of 5.31. At two hours post-injection, the MADRS-SI score decreased by 4.13 points (78% reduction), with 76% (N = 29) of patients reporting no suicidal ideation (score 0-1). Of the 28 patients who completed a one-month follow-up, 89% (N = 25) maintained a reduction in suicidal ideation (mean reduction: 4.75 points). A total of 64% (N = 16) required only one injection, while 36% required multiple injections. Three patients did not recover even after six trials of ketamine. Among 21 patients who completed six months of follow-up, 8 (28%) patients had relapsed. A/E was reported in 87% of patients, with dizziness and sedation being the most common (57%). No serious or life-threatening adverse effects were noted.

IM ketamine (0.5 mg/kg) is effective and safe for the rapid reduction of suicidal ideation.