Ketamine Overdose Symptoms, Treatment, and Long-Term Outlook

Ketamine is a dissociative anesthetic with a potential for recreational misuse.¹ Ketamine overdose has numerous troubling symptoms that can impact mental and physical functioning.² Recent studies have cited a worldwide increase in ketamine misuse, so it’s becoming more critical to understand the potential adverse effects of using this drug.^3,4

What is Ketamine Overdose or Toxicity?

Ketamine is a powerful dissociative anesthetic that can make people feel detached from things such as pain sensations and other environmental elements.⁵ Though pharmaceutical use in both human and veterinary medicine exists, there are many potential adverse effects of ketamine misuse, including the potential for dose-dependent toxicity, or ketamine overdose.²

At relatively low doses ketamine alters perception and coordination, accompanied by producing a dream-like way of thinking and euphoria.^2,6 As doses increase, the person using may begin to feel a complete separation from reality or a so-called “out of body” experience.⁶ Markedly unpleasant dissociative experiences such as these are sometimes known as a “near-death” experiences or the “K-Hole.”⁶ Loss of consciousness can also occur at high doses.⁶

High doses of ketamine can result in several health issues, including respiratory, cardiovascular, and neurological toxicity. Some of the wide-ranging adverse risks of ketamine misuse include:²

• Amnesia.
• Elevated blood pressure.
• Breathing difficulties.
• Problems with coordination and judgment.
• Seizures.
• Ulcerative cystitis.
• Addiction.

Death by ketamine overdose rarely occurs if ketamine is the only drug someone takes.⁶ However, fatal toxicity may be more likely when someone combines ketamine with alcohol, as both substances impact respiration and cardiovascular functioning.³ Combining alcohol with ketamine has also been linked to a risk for severe neurotoxicity.⁷

Furthermore, ketamine use may be associated with accidental injury and death.^2,6 This can involve falling, drowning, vehicular accidents, and hypothermia.^2,6 One study of deadly motor vehicle collisions found a disproportionately large number of ketamine-involved accident fatalities compared to other substances such as opioids and alcohol.²

Ketamine Overdose Causes and Risk Factors

Studies are still ongoing regarding ketamine dosage and toxicity, and the information available on this topic is limited, especially for human subjects.² Recreational use may entail relatively high doses of the drug to elicit a desired level of intoxication, and high-dose use can increase the likelihood of ketamine overdose symptoms.^1,2

Certain medical conditions can also exacerbate the risk of ketamine toxicity. For example, issues such as pre-existing heart disease and/or hypertension can increase a person’s risk of cardiovascular complications in association with ketamine toxicity.² This can lead to issues such as increased intracranial pressure, an increased risk for stroke, and diminished blood flow to heart muscle (i.e., myocardial ischemia).²

Ketamine Overdose Treatment

Medical monitoring may be necessary when someone experiences symptoms of a drug overdose. A single dose of ketamine can last from 15 minutes to many hours.² Because of the unpredictability of the drug’s effects, someone under the influence of ketamine should be monitored 6 hours after reported ketamine use even if asymptomatic and monitored 1 to 2 hours after the last symptom is seen to be safe.²

Ketamine overdose treatment consists primarily of supportive care, though more severe cases may require the patient to be placed on a monitor.² Intubation may be used if respiratory support is needed.² Ketamine overdose reversal is not possible via any known medication at this time.²

Doctors can use activated charcoal in a supervised medical setting to help with gastrointestinal detox in a ketamine overdose, if this is deemed necessary.² Medications can be used in an emergency room to mitigate some of the psychiatric and medical ketamine overdose symptoms.²

Once someone has been medically stabilized from a ketamine overdose, this may be an ideal time to speak to them about the benefits of seeking substance use treatment regarding their ketamine use (or use of other drugs). Continued misuse of ketamine can be dangerous. Addressing the behavioral aspect of ketamine misuse through professional intervention could be a valuable tool in preventing these dangers from being realized.

Ketamine Overdose Outlook and Prevention

An individual that experienced and recovered from acute ketamine toxicity may experience psychological disturbances, including hallucinations and unusual dreams, for days or weeks after their last use.² These effects are not considered to be permanent and fade with time.² Frequent ketamine use, however, has been linked to long-term depression, sleep issues, and deficits in memory and concentration.²

Psychological dependence has also been found in long-term use of ketamine, despite the absence of physical withdrawal symptoms.² If you are concerned about the possibility of drug dependence, it may be time to seek professional help. Medication, outpatient, and inpatient treatment are generally available to address the health effects of addiction including ketamine misuse.

Going to Rehab for Ketamine Abuse

The best way to prevent ketamine overdose and addiction is to avoid recreational ketamine use. If you or someone you care about need help with ketamine or other substance use, reach out to American Addiction Centers (AAC) to connect with an admissions navigator, who can answer your questions and explain your options.