Sublingual Dexmedetomidine for Agitation Associated with Schizophrenia or Bipolar Disorder: A Post Hoc Analysis of Number Needed to Treat, Number Needed to Harm, and Likelihood to be Helped or Harmed

Introduction: The objective was to use the evidence-based medicine metrics of number needed to treat, number needed to harm, and likelihood to be helped or harmed to appraise the clinical efficacy and tolerability of sublingual dexmedetomidine in adults with agitation associated with schizophrenia or bipolar disorder.

Methods: Sublingual dexmedetomidine data for this post hoc analysis were obtained from two similarly designed, double-blind, randomized, placebo-controlled studies of adults with schizophrenia or bipolar disorder. Response to treatment was defined as a ≥ 40% reduction from baseline in the Positive and Negative Syndrome Scale-Excited Component (PEC). Tolerability was assessed by evaluating rates of adverse events.

Results: The number needed to treat (95% confidence interval) estimate versus placebo for PEC response at 2 h post-dose was 3 (2, 3) for the sublingual dexmedetomidine 180-µg group (n = 125) and 3 (3, 4) for the 120-µg group (n = 129) in the study of patients with schizophrenia and 3 (2, 3) for the sublingual dexmedetomidine 180-µg group (n = 126) and 4 (3, 6) for the 120-µg group (n = 126) in the study of patients with bipolar disorder. Number needed to harm values versus placebo were greater than 10 for all adverse events except somnolence, where the number needed to harm (95% confidence interval) was 7 (5, 10) for all doses pooled from both studies. In all instances, likelihood to be helped or harmed values were greater than 1 for efficacy versus applicable tolerability outcomes.

Conclusions: The number needed to treat, number needed to harm, and likelihood to be helped or harmed of sublingual dexmedetomidine support a favorable benefit-risk profile in adults with acute agitation associated with schizophrenia or bipolar disorder.

Trial registration: ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT04268303 , NCT04268303.

Clinicaltrials: gov, https://clinicaltrials.gov/ct2/show/NCT04276883 , NCT04276883.