Applicable Research

Postmortem Ketamine Reports

A. A review of self-administered ketamine deaths in Australia

There were a total of 68 cases throughout Australia between 2000-2019 where self-administered ketamine was determined to be contributory to death.  In this study, it is noted that intravenously injecting ketamine quickly at high doses can weaken the body’s natural reflexes that keep your airway open, make your throat muscles tense up, and can briefly slow or stop your breathing. When someone injects ketamine themselves, the drug enters the body very quickly, which can increase these risks.

Of these 68 cases:
•82.3% of cases attributed death to toxicity (58.8% accidental, 23.5% deliberate)
•8.8% of the decedents had been prescribed ketamine
•32.4% of the decedents' final route was IV
•>40% of decedents had previous history of drug use via injection
•72.1% occured in private environments
•95.5% of cases were polydrug fatalities
•Of the cases that underwent autopsy, 82.2% involved pulmonary edema and 26.7%  involved pneumonia
•26.7% of decedents had cardiovascular disease

B. Report of deaths following illicit ketamine use in the UK
This study chronicles 696 deaths involving illicit ketamine use between 1999-2024 throughout England, Wales, and Northern Ireland.

Statistics
•Deaths involving illicit ketamine increased over 10-fold from 2014 to 2024, from 363 deaths (1999-2019) to 333 deaths (2020-2024).
•The median number of co-administered substances rose from 3 (1999–2009) to 6 (2015–2024), indicating that most deaths now occur in the context of complex polydrug use rather than ketamine alone.
•While the absolute number of deaths where ketamine was implicated increased, the proportion of cases where ketamine was the direct cause of death declined (from 60% in 2014 to 42.6% in 2024), suggesting that other substances and factors are increasingly involved.
• The proportion of decedents employed at the time of their death decreased significantly, from 53.9% (1999-2019) to  41.5% (2020-2024).
•The proportion of decedents living in the most deprived areas of the countries increased from 26.2% (1999-2019) to 33.9% (2020-2024)

Why is there a recent rise in ketamine-related deaths?
•The rise in mortality is hypothesized to be due to a series of factors: the decreasing cost/increasing availability of black market ketamine through clandenstine lab production and the increasing incidence of drug users intentionally combining substances to reach a desired effect. In some of these polydrug interactions, synergistic effects can cause fatal consequences, and the cause of death can be shared by or attributed to other substances.

•Over the years, the way people use ketamine has changed a lot. Ketamine is no longer just a party drug used in recreational settings. Many ketamine users have more complicated relationships with the substance, often using it alongside other substances like MDMA, cocaine, methamphetamine, opioids, benzodiazepines, alcohol, GHB, and others.

•The authors emphasize that policy responses should move beyond single-substance legislative controls and instead incorporate harm reduction, integrated treatment, and social support strategies to address the complex drivers of ketamine-related deaths

C. Poisonings involving ketamine reported in the USA
This study reports on characteristics surrounding reports made to the Poison Control Center involving ketamine between 2019-2021.
***Note: Ketamine statistics in the United States must be drawn from poison control center data because the Centers for Disease Control and Prevention (CDC) does not systematically report on ketamine exposures or poisonings. As highlighted in the article, this lack of CDC reporting means that the National Poison Data System (NPDS), which aggregates data from all US poison control centers, is the primary national source for ketamine-related adverse event surveillance. However, poison center data are inherently limited: cases are only captured when healthcare providers, patients, or others contact a poison center, typically for exposures that are concerning or symptomatic. This mandatory reporting nature means the data are not representative of the general population or all ketamine users, but rather reflect a subset with adverse events or suspected toxicity. Therefore, these statistics should not be used to estimate prevalence or patterns of ketamine use in the broader public.

Summary of statistics from the research (2019–2021):

• Reported ketamine exposures increased 81.1% from 37 cases in Q1 2019 to 67 cases in Q4 2021.

• Most patients were male (57.1%).

• Intentional misuse/abuse accounted for 39.5% of cases, followed by suspected suicide attempts (19.7%) and unintentional exposures (18.9%).

• Major adverse effects or death occurred in 19.6% of cases.

• Polydrug use was common (33.4%), with benzodiazepines (14.6%), alcohol (10.3%), and opioids (8.7%) most frequently co-used.

• Co-use of GHB and opioids significantly increased risk for major adverse effects or death.

• Injection-only administration was also associated with higher risk.
  
  

D. A systematic review of overdoses and death associated with ketamine use

This study reviews 34 articles found within medical literature databases throughout the world, chronicling a total of 138 deaths and 312 overdoses reported.

•Polysubstance use was present in 53% of articles. Acute intoxication due to polysubstance misuse  was the cause of death in 1/3 of the cases.
•Most deaths occurred in recreational settings; no deaths were due to a prescribed antidepressant in a therapeutic setting.
•Ketamine and its analogues were exclusively determined to be cause of death in 9 cases (6.5%)

The following tables are excerpts from the review, noting deaths and overdoses related to the use of ketamine and its analogues in Table 2 and Table 3 respectively: