Although the overall ketamine exposures were low, researchers say the findings add to a growing body of research that suggests recreational ketamine use may be on the rise.
“Ketamine is by no means the most dangerous drug, but it could be dangerous if combined with drugs such as alcohol or if used in potentially hazardous situations – physically hazardous or socially hazardous,” lead author Joseph Palamar, PhD, associate professor and epidemiologist at New York University Langone Health, New York, told this news organization.
“People who decide to use ketamine recreationally need to be educated about potential risks,” Dr. Palamar said.
The findings were recently published online in the Journal of Psychopharmacology.
More widespread use
Researchers noted that ketamine use has become more widespread in the United States due in part to increasing availability of ketamine in both clinical and nonclinical settings.
Previous work by Dr. Palamar documented an increase in recreational use of ketamine at dance clubs and an increase in ketamine seizures by the Drug Enforcement Administration.
In the current study, investigators analyzed data from the National Poison Control database and included cases reported by 51 of the 55 poison control centers in the United States.
They identified 758 cases involving ketamine exposure between the first quarter of 2019 and the last quarter of 2021 in individuals aged 13 and older, more than half of whom were men.
The number of ketamine exposures increased 81.1% during the study period, rising from 37 to 67 (P = .018).
Nearly 40% of callers reported intentional misuse or abuse of ketamine, while 19.7% involved a suspected suicide or suicide attempt. The ketamine exposure was unintended in 18.9% of cases, and 10.6% of calls involved an adverse drug reaction.
Onep-third of cases involved co-use of other substances, most commonly benzodiazepines, opioids, or alcohol.
The route of administration was ingestion for 44.3%, injection for 18.8%, and inhalation for 17.6%. Another 19.3% involved another route or a combination of routes.
Nearly 20% of cases reported a major adverse effect or death, 42.8% reported a moderate effect, 25.8% a minor effect, and 11.8% no effect. There were seven deaths reported in ketamine-related calls, although Dr. Palamar noted it is unlikely those deaths were due solely to ketamine use.
Researchers didn’t analyze specific harms reported in the calls, but chronic and heavy ketamine use has been previously associated with cognitive impairment, urinary cystitis and other urinary tract issues, and upper gastrointestinal problems.
In addition, using ketamine with gamma-hydroxybutyrate (GHB) or opioids was associated with a significantly higher risk for major adverse effects (P < .001 for both). Injecting ketamine was also linked to a higher prevalence of major adverse effects, although the association did not quite reach significance (P < .05).
Cause for concern
Commenting on the findings, Timothy Wiegand, MD, director of Addiction Toxicology and Toxicology Consult Service and associate professor of emergency medicine at the University of Rochester Medical Center and Strong Memorial Hospital, New York, noted the data on co-use of ketamine with other drugs were cause for concern.
“I think the co-occurring behaviors are critical here with concomitant use of opioids and GHB, intravenous drug use, or that it is used in an attempt to harm one’s self because it allows for identification of these behaviors or use patterns,” said Dr. Wiegand, who was not involved with the research.
He added that it is important for “addiction providers and others in medicine or in the addiction field to be aware of trends” associated with ketamine.
“At the same time, a focus on general prevention, and access to care and treatment, and understanding how to implement harm reduction strategies remain high priorities,” Dr. Wiegand said.
The study was funded by the National Institute on Drug Abuse. Dr. Palamar has reported consulting for Alkermes. Dr. Wiegand has reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.