Low-dose IV infusions of ketamine are safe and effective in treating chronic pain, a new study says.
Ketamine infusions as part of comprehensive clinical pain care helped as many as 46% of patients improve their physical function, sleep quality and pain management, researchers reported this week in the journal Regional Anesthesia & Pain Medicine.
“This study provides evidence for ketamine's role in chronic pain management,” said lead researcher Hallie Tankha, a clinical pain psychologist in Cleveland Clinic’s Primary Care Institute.
“This is in line with my clinical experience as a pain psychologist, as patients often describe ketamine infusions as ‘life changing,’ ” Tankha said in a news release. “I'm encouraged by treatments that can be integrated into comprehensive care approaches, and this study demonstrates ketamine can be safely and effectively implemented in pain management settings.”
Ketamine is used as an anesthetic for surgery and a treatment for depression, according to Drugs.com.
It’s not an opioid, but instead works by blocking a key brain chemical called N-methyl-D-aspartate, or NMDA, according to Johns Hopkins University. It was initially developed in the 1960s and used as a battlefield anesthetic in the Vietnam War.
For the new study, researchers tracked more than 1,000 patients who received a standard ketamine infusion of 0.5 milligrams for every kilogram of body weight. The patients received the infusion over 40 minutes for five days in a row.
More than 90% of patients completed all five treatment days, researchers said. The research team then followed their progress.
Between 20% and 46% of patients achieved clinically meaningful improvements in their pain, physical function and sleep, results showed. These benefits held for at least six months, and nearly half of patients also had improvement in pain-related anxiety.
About 80% of patients chose to return for additional infusions, researchers noted.
Ketamine treatment also was safe, with minimal side effects and no serious health problems. Hallucinations were the most-reported side effect, but they were rare, the study said.
“We know millions of Americans are suffering from chronic pain and this research addresses critical gaps in pain management and shows a significant step forward in improving care for those patients who have otherwise exhausted all other treatment options,” senior researcher Dr. Pavan Tankha said in a news release. He’s medical director of comprehensive pain recovery in Cleveland Clinic’s Neurological Institute.
“The findings of the research represent a meaningful step toward improved quality of life and may accelerate access to this treatment option for patients all over the country,” Tankha said.
More information
Johns Hopkins Bloomberg School of Public Health has more on ketamine.
SOURCE: Cleveland Clinic, news release, Oct. 6, 2025