Intravenous (IV) esketamine is as safe and effective as IV ketamine for patients with treatment-resistant depression, new research suggests.
“Our study was the first randomized clinical trial directly comparing ketamine and esketamine in treatment-resistant depression,” senior investigator Lucas C. Quarantini, MD, PhD, Division of Psychiatry.
The findings showed that esketamine was not inferior to ketamine in remission of depressive symptoms 24 hours after a single IV dose; and the two treatments had similar side effect profiles, Quarantini said.
Furthermore, “our results showed that only the number of treatment failures was an important factor for the remission of symptoms,” he added.
The findings were scheduled to be presented this month at the Anxiety and Depression Association of America (ADAA) Conference 2020, along with publication in the Journal of Affective Disorders. However, the ADAA conference was cancelled in the wake of the coronavirus pandemic.
Results showed esketamine to be noninferior to ketamine as determined by the Montgomery-Asberg Depression Rating Scale (MADRS).
At 24 hours following infusion, 24.1% of the ketamine group versus 29.4% of the esketamine group showed remission of depression. The difference of just 5.3% confirmed noninferiority.
Although ketamine showed a tendency to have a longer-lasting antidepressant effect compared with esketamine, the difference did not reach statistical significance and should be evaluated in future studies, the investigators note.
Both treatments were safe and well tolerated. Consistent with previous studies, the most frequent side effects were dissociative symptoms, including derealization, depersonalization, and cardiovascular changes, and increased blood pressure and heart rate, which occurred equally in both groups. There were no serious adverse events in either study group.
“What our study adds to what has been previously published is that the only way to really analyze if two drugs are equivalent is to compare them in a head-to-head trial; and that was what we did,” he said.