Ketamine Infusion Clinic Reports Real-World Patient Experiences

“In clinical trials, they report a 60% to 70% response rate,” Cusin said. “We don’t see that.” However, about one-third in total have at least a partial response, which Cusin defines as a 35% or greater improvement in QIDS.

Cusin attributes the clinic’s lower response and remission rate to the greater illness burden of their patients. All of them are taking multiple psychotropics, have failed to respond to anywhere from four to 15 antidepressant medications, and have numerous medical and psychiatric comorbidities. One-quarter to one-third of the clinic’s patients have already tried and failed electroconvulsive therapy and/or transcranial magnetic stimulation.

“When patients have an exacerbation of stress or a COVID infection, for example, their depression gets worse, and the ketamine seems to work less,” Cusin said. Still, half of those treated choose to continue with ketamine maintenance, even some who are deemed non-responders. “Even the smaller improvement was enough for them.”

The clinic is not able to predict who is going to respond. However, use of illicit substances, particularly cannabis, blocks the effect of ketamine, so the clinic discourages patients with active substance use from obtaining treatments. Cusin also avoids treating those with current psychosis “because we don’t know if it’s safe. There is no data.”

Each ketamine infusion costs $550, according to the clinic website, and is not typically covered by insurance. Cusin said ongoing maintenance infusions are needed, so she has careful conversations about financial planning and scheduling at the outset. “Stopping is almost invariably associated with relapse,” and is almost worse than never starting, she said, adding that patients then return in crisis. “I tell patients, ‘If this works, you have to stick with the program.’ … So, you must make sure it’s sustainable.”

Cusin said that patients rarely seem to be seeking the chance to get high—fewer than 1%. Regardless, euphoric effects dissipate after the first treatment or two. As for side effects and adverse events: 35% of the clinic’s patients require ondansetron or prochlorperazine for nausea, while another 30% to 40% require lorazepam for anxiety, dissociation, psychotic-like experiences, or perceptual disturbances. Most resolve within an hour of treatment, Cusin said.

Patients commonly experience insomnia the night after treatment, Cusin said. As for hypertensive episodes, they are more common with higher ketamine doses and in males over the age of 50.

While the clinic is reasonably sure that ketamine maintenance therapy is safe and effective, Cusin said there are concerns about this type of long-term, repeat, off-label use. They include the potential for Olney’s lesions, addiction, and neurotoxicity.

At the same time, the clinic treats patients as young as 15. “What are the long-term consequences of providing ketamine maintenance therapy on a young brain?” Cusin asked. “We don’t know what we don’t know.”

She discloses to her patients that beyond five years, “we have no idea…. Our fear is of some long-term unknown side effect. Most of our patients accept that and tell us, ‘I could be dead next month from suicide, so I’ll accept the potential downstream risk.’”

Cusin stressed that it is important to integrate cognitive behavioral or dialectical behavior therapy, education, and/rehabilitation into ketamine therapy. “A lot of our patients have forgotten how to live a life after 10 years of depression,” she said. “They have no relationships, no job, no structure, nothing. So, we have to figure out how to help them rebuild after the depression lifts.” ■