We assessed safety and efficacy of oral ketamine vs. diclofenac to treat depression.

Abstract

Background Ketamine is a glutamate N-methyl-d-aspartate receptor antagonist capable of exerting antidepressive effects in single or repeated intravenous infusions. The objective of this study was to investigate the safety and the efficacy of oral ketamine vs. diclofenac monotherapy in reducing symptoms of mild to moderate depression among patients with chronic pain.

Methods This study is a 6-week, randomized, double-blind, controlled, parallel-group trial with two intervention arms (ketamine, fixed daily dosage of 150 mg vs. diclofenac, fixed daily dosage of 150 mg). Twenty participants in each arm completed the trial program all of whom had two post-baseline measurements at week 3 and week 6. Reduction in depression symptoms was assessed using the Hamilton Depression Rating Scale (HDRS) and the hospital anxiety and depression subscale for depression (HADS Depression ) scores at baseline and week 3 and week 6 post-intervention.

Results Significantly lower HDRS scores were observed in the ketamine treatment group as early as 6 weeks post-intervention (P=0.008). By comparison, mean (±standard deviation) HADS depression subscale scores were significantly lower for individuals receiving ketamine compared to diclofenac for both post-baseline measures at week 3 (6.95±1.47 vs. 8.40±1.6, P=0.005) and week 6 (6.20±1.15 vs. 7.35±1.18, p=0.003).

Limitations The limitations of the present study were its small sample size and the short-term follow-up period.