Esketamine: A Novel Option for Treatment-Resistant Depression

Objective:To review the pharmacology, pharmacokinetics, efficacy, safety, use requirements, and place in therapy of esketamine for treatment-resistant depression (TRD). Data Sources: A comprehensive PubMed search (1966 to October 2019) was conducted using the search terms depression, treatment-resistant, suicide, intranasal, esketamine, and JNJ-54135419. Additional data were obtained from references of identified articles, governmental sources, manufacturer product labeling, and Clinicaltrials.gov . Study Selection and Data Extraction: All English-language trials evaluating intranasal esketamine for TRD were included and discussed. Data Synthesis: Intranasal esketamine was approved by the US Food and Drug Administration, in conjunction with an oral antidepressant, for treating TRD in adults. Two short-term trials (TRANSFORM-1 and -2) found statistically significant reduction in the Montgomery-Asberg Depression Rating Scale score at day 28 for the fixed 56-mg dose (-4.1; 95% CI = -7.69 to -0.49; P = 0.027 [exploratory]) and flexible-dosed arms (-4.0; 95% CI = -7.31 to -0.64; P = 0.02), though the fixed-dose 84-mg arm (-3.2; 95% CI = -6.88 to 0.45; P = 0.088) of TRANSFORM-1 and TRANSFORM-3 did not (-3.6; 95% CI = -7.2 to 0.07; P = 0.059). Two long-term trials (SUSTAIN-1 and -2) suggested maintenance of response with continued use. Esketamine's adverse effects include dizziness, dysgeusia, somnolence, dissociation, suicidal thoughts and behaviors, and increased heart rate and blood pressure. Relevance to Patient Care and Clinical Practice: Although providing a novel antidepressant mechanism and formulation for TRD, esketamine's role in treatment will likely be limited by cost, administration, and diversion concerns. Conclusion: Intranasal esketamine significantly reduced depression symptoms in TRD, though with tolerability issues.