From the Guidelines
Ketamine toxicity symptoms include amnesia, delirium, vivid hallucinations, tachycardia and arrhythmias, mild respiratory depression, confusion, irrationality, violent or aggressive behavior, vertigo, ataxia, slurred speech, delayed reaction time, euphoria, altered body image, analgesia, and coma, as reported in a study published in Pediatrics 1. The symptoms of ketamine toxicity can vary in severity and may include:
- Increased heart rate and blood pressure
- Confusion, agitation, and hallucinations
- Dissociative effects, where patients feel detached from reality
- Respiratory depression, seizures, muscle rigidity, and hyperthermia in more severe cases
- Nausea, vomiting, excessive salivation, and nystagmus (involuntary eye movements) Ketamine's effects on the body are due to its stimulation of the sympathetic nervous system and its action as an NMDA receptor antagonist in the brain, as described in a study published in Gastroenterology 1. It is essential to note that ketamine toxicity can develop rapidly, typically within minutes of administration, and can last for several hours depending on the dose and route of administration. Treatment for ketamine toxicity focuses on supportive care, including:
- Monitoring vital signs
- Maintaining airway patency
- Using benzodiazepines to manage agitation or seizures If ketamine toxicity is suspected, it is crucial to seek immediate medical attention, as severe cases can be life-threatening.
From the FDA Drug Label
Changes in heart rate and blood pressure, respiratory depression, and apnea may occur with overdosage or by a rapid rate of administration of ketamine hydrochloride.
In a context of drug abuse, ketamine hydrochloride may produce a variety of symptoms including anxiety, dysphoria, disorientation, insomnia, flashback, hallucinations, and feelings of floating, detachment and being "spaced out".
Respiratory disorders: Respiratory depression and apnea following rapid intravenous administration of high doses of ketamine hydrochloride; laryngospasm, and airway obstruction.
The symptoms of ketamine toxicity include:
- Respiratory depression
- Apnea
- Changes in heart rate and blood pressure
- Anxiety
- Dysphoria
- Disorientation
- Insomnia
- Flashback
- Hallucinations
- Feelings of floating, detachment and being "spaced out"
- Laryngospasm
- Airway obstruction 2 2 2
From the Research
Ketamine Toxicity Symptoms
Ketamine toxicity can manifest through various symptoms, including:
- Dissociation
- Nausea
- Headache
- Elevated heart rate
- Blood pressure increases 3
- Lower urinary tract symptoms, such as dysuria or urgency, particularly with esketamine treatment 3
- Cognitive impairments at high doses, although esketamine clinical trials suggest no increased risk of cognitive impairment when used appropriately 3
Severe Toxicity and Overdose
Severe cases of ketamine toxicity can lead to overdose and even death, often in the context of poly-substance use 4. A systematic review found 312 reported overdose cases and 138 deaths associated with ketamine and its analogues, with most cases involving males and poly-substance use 4. However, no cases of overdose or death were reported in therapeutic settings where ketamine was used as an antidepressant 4.
Therapeutic Context
In a therapeutic context, ketamine is considered safe when used appropriately, with the World Health Organization listing it as an essential medicine 4. Clinicians should remain vigilant, but this should not deter appropriate prescription 4. The use of ketamine in neuropsychiatric disorders, including depression, bipolar disorder, and anxiety spectrum disorders, has been supported by considerable clinical research 5.