Ketamine exposure demographics and outcomes over 16 years as reported to US poison centers.

BACKGROUND: This study sought to examine ketamine exposures reported to US poison centers over the past 16 years and identify trends in exposures and outcomes.

METHODS: A retrospective review was performed of all cases involving ketamine exposures reported to US poison centers and entered into the National Poison Data System from 2000 to 2015. Cases were divided into those involving ketamine alone and those involving ketamine and other agents. Data collected included: age, sex, form of ketamine used, reason for exposure, and outcome.

RESULTS: A total of 3109 cases were evaluated. 1595 (51%) reported ketamine to be the only substance exposure, while 1514 (49%) involved multiple substances with ketamine. For single agent exposures, more involved males (67%) between the ages of 16-25 years (49%). Single agent ketamine exposures peaked between 2000 and 2002, fell consistently until 2008; then rebounded to previous peak levels through 2015. Intentional exposures (65% of all cases) were the most common reason for single agent ketamine exposures. 53% of ketamine-only cases resulted in minor effects, with two deaths. In contrast, ketamine exposures with multiple agents resulted in outcomes judged as moderate or worse in 62% of cases, including 20 deaths.

CONCLUSION: Single-agent ketamine exposures reported to US poison centers have rebounded to historical peaks in recent years. More deaths and serious outcomes were reported in ketamine exposures involving multiple substances.