Versatile and safe, Ketamine can help with sedation, induction, asthma and pain. Can a shot of it even treat suicidality?
Versatile and safe, Ketamine can help with sedation, induction, asthma and pain. Can a shot of it even treat suicidality?

Major Indications
New indications for Ketamine seem to be popping up every day. Its primary ED use is for procedural sedation, though the only FDA approved use is for induction of general anesthesia. It is also used off label as a medical restraint for patients with behavioral volatility, as a primary analgesic, for rapid sequence induction, for status epilepticus, and for moderate to severe asthma exacerbations. Outside the ED setting, it is being studied for use in depression and in chronic pain syndromes, such as fibromyalgia. It can be administered IV, IM, and intranasally.
In The News
Ketamine has received significant press recently for its use in patients with depression and suicidal ideation. Patients with depression reportedly saw a significant decrease in suicidal ideation after just a single treatment with Ketamine [1]. Could this be useful in EDs that are often crowded with psychiatric patients? It remains to be seen.
How It Works
Ketamine is a dissociative agent and NMDA antagonist. It causes a trance-like state in which the patient is not aware of their surroundings or of painful stimuli.
Notable History
Ketamine was originally developed in the 1960s, synthesized as a derivative of phencyclidine (PCP). It received FDA approval in 1970, and was first used clinically as an anesthetic agent for soldiers in the Vietnam War. Recreational use of Ketamine followed quickly after its discovery, starting on the west coast and spreading internationally. Because of its complex synthesis, illicit Ketamine is typically obtained from diversion or theft of legally synthesized pharmacologic Ketamine. It is typically used recreationally in sub-anesthetic doses, and because of its amnestic properties leaves users at risk for sexual assault.
Adverse Events
Serious adverse events are rare. Emergence phenomena may occur, as well as vomiting. Tachycardia and hypertension can also occur but are typically transient.
Black Box Warning
Ketamine carries a black box warning for the risk of emergence reactions.
Cautions
Use with caution in patients who are already tachycardic and hypertensive or who have coronary artery disease. Safety in elderly patients has not been well studied. However, hopefully we can finally lay to rest the concern of Ketamine increasing intra-cranial pressure (ICP). Head injury or elevated ICP was long considered a contra-indication to Ketamine use, but sufficient evidence is available from more recent studies showing that Ketamine use does not increase ICP [2, 3]. Ketamine is pregnancy class B.
Dosing
For procedural sedation and for intubation, doses are typically 1-2mg/kg IV. Dosing is not as well defined for other uses. In studies of Ketamine for sub-dissociative analgesia or for asthma exacerbations doses such as 0.2mg/kg followed by an infusion at 0.5mg/kg/hr are often used. Ketamine has also been studied in the ED setting for analgesia using 1mg/kg intranasally [4]. There are no defined adjustments for hepatic or renal disease.
Cost
A 20mL vial of 10mg/mL (200mg) costs around $18. Street value is around $50-150 per 1000mg.
Christina Shenvi, MD, PhD is an assistant professor in the department of emergency medicine at the University of North Carolina.
REFERENCES
1. PriceRB, Losifescu DV, Murrough JW, et al. Effects of Ketamine on Explicit and Implicit Suicidal Cognition: A randomized Controlled Trial in Treatment-Resistant Depression, Depression and Anxiety, Apr 2014, 31(4);335-43 PMID 24668760
2. Zeiler FA, Teitelbaum J, West M, Gillman LM, The Ketamine Effect on ICP in Traumatic Brain Injury. Neurocrit Care, Feb 2014 Epub ahead of print PMID 24515638
3. Chang LC, Raty SR, Ortiz J, et al The emerging use of ketamine for anesthesia and sedation in traumatic brain injuries, CNS Neurosci Ther, Jun 2013; 19(6);390-5, PMID 23480625
4. Yeaman, F, Meek R, Egerton-Warburton D, et al Sub-dissociative-dose intranasal ketamine for moderate to severe pain in adult emergency department patients’ EmergMedAustralasia June 2014, 26(3);237-242 PMID 24712757