In the second RCT (n = 23), researchers randomized patients with mild-to-moderate depression and comorbid chronic headaches to take oral ketamine (50 mg tid) or oral diclofenac (50 mg tid) and measured effect size on standardized depression scores at 3 weeks (no difference) and 6 weeks (Cohen d effect size = 0.79 [rated as a moderate effect]; P = .017).4
Nasal esketamine + oral antidepressants boosts treatment response rates
A meta-analysis with 4 RCTs (N = 708) evaluating intranasal esketamine vs placebo as an adjunct to oral antidepressants for patients with predominantly treatment-resistant major depression found that it boosted response rates by about 40%. Researchers randomized patients to intranasal esketamine (mostly 28-84 mg twice weekly for 28 days) or placebo spray as an adjunct to oral antidepressants (duloxetine, escitalopram, sertraline, venlafaxine).
The primary outcomes were treatment response (≥ 50% reduction in depression scores) or remission (a MADRS score < 12). Adjunctive intranasal esketamine produced greater rates of treatment response compared to placebo at 24 hours (21% vs 7%; relative risk [RR] = 8.4; 95% CI, 1.4 to 21.2; P < .02; NNT = 7) and at 28 days (59% vs 43%; RR = 1.4; 95% CI, 1.2 to 1.60; P < .0001; NNT = 6).5 Adjunctive intranasal esketamine also produced greater rates of remission at the end of the study (mostly at 28 days), compared with placebo (41% vs 25%; RR = 1.4; 95% CI, 1.2 to 1.7; P = .0004; NNT = 7).5 The authors rated study quality as moderate to high.
Adverse effects are common, may cause Tx discontinuation
Ketamine-produced adverse effects (AEs) included confusion (2 trials; N = 76; OR = 3.7; 95% CI, 1.1-12) and emotional blunting (1 trial; N = 30; OR = 23; 95% CI, 1.1-489).1
A 2018 systematic review assessed the safety of ketamine in depression after single and repeated dose in 60 studies (N = 899; 20 RCTs, 17 open-label-trials, 20 case series, and 3 retrospective studies). The most common AEs reported were headache (35% of studies), dizziness (33%), dissociation (28%), elevated blood pressure (28%), and blurred vision (23%), with the majority reported to resolve shortly after administration. The most common psychiatric AE was anxiety (15%).6 Included studies varied greatly in design and dosage form, and no meta-analysis could be performed.