Consistent findings
Commenting on the findings, Gerard Sanacora, MD, PhD, professor of psychiatry at Yale University, New Haven, Conn., noted that key study limitations include the small sample size and lack of a placebo group.
Nevertheless, “I think it is fair to say that it is unlikely that the treatments are markedly different in their effects on depression over 24 hours,” he said in an interview.
Dr. Sanacora, director of the Yale Depression Research Program, was not involved with the current research.
The findings are “consistent with what we can extrapolate from other clinical trials examining racemic ketamine and esketamine separately,” he said.
Dr. Sanacora noted that because esketamine has been previously shown to be a more potent anesthetic than arketamine, the other component of racemic ketamine, it is “the primary form of ketamine used as an anesthetic agent in several regions of the world with the idea that it may be more selective for the desired anesthetic effect.”
Even with its limitations, the study does offer some notable yet preliminary insights, he added.
“It is interesting to see varying degrees of numerical differences between the two treatments at different time points,” Dr. Sanacora said. In addition, “there may be some differing effects between the two treatments over time, but we really do not have enough data to say much of anything [about that] with confidence at this point.”
The study was supported by the Programa de Pesquisa para o SUS through Fundação de Amparo à Pesquisa do Estado da Bahia. Dr. Quarantini has reported receiving consulting fees from Allergan, Abbott, Janssen Pharmaceuticals, and Lundbeck, and research fees from Janssen Pharmaceuticals. The other study authors’ disclosures are listed in the published article. Dr. Sanacora has reported consulting and/or conducting research from several pharmaceutical companies. He also holds shares in BioHaven Pharmaceuticals and is coinventor on a patent called “Glutamate Agents in the Treatment of Mental Disorders.”
A version of this article originally appeared on Medscape.com.