Weekly / November 7, 2024 / 73(44);1010–1012

Investigation and Findings

Data on drug overdose deaths with unintentional or undetermined intent come from SUDORS, which includes information from death certificates, medical examiner or coroner reports, and postmortem toxicology reports.^§ Data are abstracted on all substances reported to cause death (i.e., involved) and substances detected through toxicology testing.^¶ Decedent demographics and other overdose characteristics were analyzed among 45 jurisdictions (44 states and the District of Columbia [DC]),** and trend analyses were conducted among 28 jurisdictions (27 states and DC).^†† Analyses were restricted to deaths with toxicology reports or with ketamine listed as a cause of death on the death certificate. Ketamine detection included toxicology results for ketamine or its metabolites.^§§ Among deaths with ketamine detected, drug involvement was analyzed to ascertain which drug or drugs caused death. This activity was reviewed by CDC, deemed not research, and was conducted consistent with applicable federal law and CDC policy.^¶¶

During July 2019–June 2023, a total of 228,668 drug overdose deaths were identified in 45 jurisdictions. Ketamine was detected in 912 (0.4%) overdose deaths, listed as involved in 440 (0.2%) deaths, and was the only substance involved in 24 (0.01%) deaths (Table). A majority of deaths with ketamine detected involved illegally manufactured fentanyls (IMFs) (58.7%), followed by methamphetamine (28.8%) and cocaine (27.2%). Overall, 82.4% of deaths involved either IMFs, methamphetamine, or cocaine. Approximately one third (34.8%) of decedents in whom ketamine was detected were aged 25–34 years, and approximately three quarters were males (71.3%) and non-Hispanic White persons (73.7%).

Among 172,475 overdose deaths in 28 jurisdictions during July 2019–June 2023, <1% had ketamine detected (692 deaths; 0.4%) or were classified as ketamine-involved (348 deaths; 0.2%). The number and percentage of deaths with ketamine detected increased during July 2019–June 2023 from 47 (0.3%) to 107 (0.5%), with notable increases as early as July–December 2020

Conclusions and Actions

During July 2019–June 2023, although ketamine was detected or involved in <1% of all drug overdose deaths, overdose deaths with ketamine detected increased. Almost all overdose deaths with ketamine detected involved other substances, mostly IMFs or stimulants; however, the source of ketamine (e.g., illegally purchased or prescribed) is unknown. Because analyses included a subset of jurisdictions, findings might not be generalizable to the entire United States. In addition, the scope of postmortem toxicology testing varies within and across jurisdictions, and ketamine might not be included in testing panels or be tested for in all postmortem samples (4), which could lead to an underestimation of ketamine detection. Despite the lack of uniform testing, ketamine detection among overdose deaths has increased over time, yet both detection and involvement accounted for a small proportion of overdose deaths. As polysubstance use (5) and use of ketamine for treatment-resistant depression and in compounded formulations*** increase, continued monitoring is needed to identify potential changes in the detection and involvement of ketamine in overdose deaths and to better understand potential drug interactions or circumstances leading to death.