Why a ketamine-like drug is being used to treat depression

The Food and Drug Administration in March approved a big pharma variant on the hallucinogenic club drug Special K for the treatment of depression.

Yes, you read that right.

Ketamine, which has long been used as an anesthetic, has increasingly been tried off-label by psychiatrists as a last-ditch effort to treat the 12 to 20 percent of patients with depression who don’t respond to other antidepressant medications or treatments.

Building on years of preliminary research about ketamine’s potential benefits for depression, Johnson & Johnson developed a drug called esketamine, sold under the brand name Spravato. The nasal spray is designed to alleviate depressive symptoms within hours — much faster than the other antidepressants on the market, such as Prozac, which can take weeks or months to act.

In February, an FDA panel determined, in a 14-2 vote, that esketamine’s benefits outweigh its risks and recommended that the agency approve the drug. The approval came on March 5, the first new antidepressant type to be greenlit by the agency in decades.

”There has been a long-standing need for additional effective treatments for treatment-resistant depression, a serious and life-threatening condition,” said Tiffany Farchione, acting director of the Division of Psychiatry Products in the FDA’s Center for Drug Evaluation and Research, in a press release. And to date, there have been frustratingly few options available to patients.

For now, esketamine is only approved for adults with “treatment-resistant depression,” who are supposed to take esketamine in conjunction with another oral antidepressant. And because it can sedate patients and bring on out-of-body experiences, the FDA is only making it available through certified clinics, where patients are to be monitored for at least two hours after taking the drug.

As Megan Thielking points out in Stat, this requirement may raise logistical challenges for clinics. “Many health care facilities aren’t set up to have patients wait in the office for several hours under observation. A health care facility also might not have enough staff to properly monitor them.”

Before the approval, more and more people with major depression seemed to be trying ketamine. Anecdotes like this one from a Vox contributor, who felt relief from the drug, had begun to surface.

But while some patient and doctor groups are hailing the approval, others aren’t so sure there’s enough evidence to justify it.

That’s because the benefits of ketamine and esketamine aren’t yet well understood. According to the FDA, the drug has only been studied in four clinical trials, three of them lasting just four weeks. And the results were pretty mixed. Per the agency:

In one of the short-term studies, Spravato nasal spray demonstrated statistically significant effect compared to placebo on the severity of depression, and some effect was seen within two days. The two other short-term trials did not meet the pre-specified statistical tests for demonstrating effectiveness. In the longer-term maintenance-of-effect trial, patients in stable remission or with stable response who continued treatment with Spravato plus an oral antidepressant experienced a statistically significantly longer time to relapse of depressive symptoms than patients on placebo nasal spray plus an oral antidepressant.

Though some of the patients who took esketamine experienced relief of their depressive symptoms, side effects — including dissociation, dizziness, nausea, sedation, anxiety, a lack of energy, increased blood pressure, vomiting, and feeling drunk — were also common.

“The clinical benefit of esketamine appears to be comparable to that of ketamine,” UpToDate, the physicians’ resource, warned. “The demonstrated benefit of ketamine is only short lived, the drug is associated with bladder toxicity and is potentially neurotoxic, and ketamine is liable to abuse [or] diversion.” A recent perspective in JAMA, about evolving treatments for depression, noted, “Potential long-term risks include tolerance, abuse, and misuse.”

It’s also not yet clear whether ketamine is a real antidepressant or just triggers a feeling of euphoria. But the FDA said the medical need for another option for patients with depression justified the approval. We’re sure to learn more now that patients will have the opportunity to try it.