Reduced-dose intramuscular ketamine for severe agitation in an academic emergency department

Clin Toxicol (Phila). 2020 Apr;58(4):294-298. doi: 10.1080/15563650.2019.1643468. Epub 2019 Jul 23.


Introduction: Rapid sedation of severely agitated patients is often necessary to ensure the safety of patients and healthcare workers. Intramuscular (IM) ketamine 4-6 mg/kg was previously studied but may carry an increased risk of intubation and other adverse effects. Therefore, the purpose of this case series was to describe the efficacy and safety of a reduced-dose (2 mg/kg) IM ketamine guideline.Methods: Consecutive patients receiving IM ketamine for agitation in the emergency department via our reduced-dose guideline were included. Successful sedation of the agitated patient was defined as documentation from a healthcare provider, a lack of additional sedating medication administration for 30 min following administration of IM ketamine, or ability to complete necessary procedure.Results: Of 15 patients included in this case series, 13 (87%) were adequately sedated with no subsequent intubations due to excess ketamine. The median total dose administered was 157.5 mg and the median weight-based dose was 2 mg/kg. In 11 of the 15 cases, reduced-dose ketamine was used as a second-line agent.Conclusion: Reduced-dose IM ketamine may be effective for severe agitation, particularly when used as a second-line agent.

Keywords: Ketamine; agitation; intubation; safety; sedation.

MeSH terms

  • Adult
  • Aged
  • Dose-Response Relationship, Drug
  • Emergency Service, Hospital*
  • Female
  • Humans
  • Hypnotics and Sedatives / administration & dosage*
  • Injections, Intramuscular
  • Ketamine / administration & dosage*
  • Male
  • Middle Aged
  • Psychomotor Agitation / drug therapy*
  • Retrospective Studies
  • Treatment Outcome
  • Young Adult


  • Hypnotics and Sedatives
  • Ketamine