Ketamine is a dissociative anesthetic that has both anesthetic and some hallucinogenic properties. It can distort perceptions of sight and sound and make a person feel disconnected from their body and environment. It’s used medically as a short-acting injectable anesthetic for both humans and animals.

Ketamine has several medical applications:

• Anesthesia: It’s widely used as an anesthetic for diagnostic and surgical procedures, especially for short procedures or as an induction agent before other general anesthetics. It’s often preferred in emergency settings due to its relatively safe profile, maintaining normal pharyngeal and laryngeal reflexes and spontaneous respiration.
• Pain Management: Ketamine is effective for treating severe pain, including trauma, fractures, and chronic pain conditions, often at lower “sub-dissociative” doses.
• Treatment-Resistant Depression and Suicidal Ideation: A specific form of ketamine, esketamine (Spravato®), is FDA-approved as a nasal spray for treatment-resistant depression when used in conjunction with an oral antidepressant. Other forms of ketamine (racemic ketamine) are used off-label for depression, anxiety, and PTSD, though more research is needed to fully understand long-term effectiveness and safety for these uses.
• Refractory Status Epilepticus: It’s also used in some cases of severe, prolonged seizures that don’t respond to other treatments.

The exact mechanisms of how ketamine produces all its effects are still being researched, but it primarily acts as an NMDA receptor antagonist. This means it blocks the N-methyl-D-aspartate (NMDA) receptor, a receptor for the neurotransmitter glutamate in the brain. This inhibition of NMDA receptors is thought to be key to its anesthetic and pain-relieving effects.

For its antidepressant effects, it’s believed that other mechanisms are also involved, possibly including:

• Indirect or direct stimulation of AMPA receptors, which may lead to the formation of new synapses (connections between brain cells).
• Effects on the mTOR pathway, which is associated with the growth of new neural connections.
• Boosting levels of certain neurotransmitters like norepinephrine, dopamine, and serotonin.

Ketamine can cause a range of side effects, which can vary depending on the dose, individual sensitivity, and whether it’s used alone or with other substances.

Common short-term side effects may include:

• Disorientation, confusion, or loss of motor coordination
• Dizziness, nausea, vomiting
• Increased blood pressure, heart rate, breathing, or body temperature
• Changes in sensory perceptions, including visual or auditory hallucinations
• Feeling detached from oneself or surroundings (“dissociative experience,” or “k-hole” at higher doses)
• Blurred vision, slurred speech, drowsiness
• Numbness, feeling uncoordinated

More serious or long-term concerns, especially with misuse or high doses, can include:

• Cardiovascular issues: Significant increases in heart rate and blood pressure can be dangerous for individuals with pre-existing heart conditions.
• Respiratory depression: Especially with overdose or rapid infusion, breathing can become dangerously slowed.
• Urinary Tract Damage (“Ketamine Bladder Syndrome”): Chronic, high-dose recreational use can lead to severe and painful bladder problems, including ulcers and incontinence, and potentially kidney issues.
• Psychiatric disturbances: Agitation, depression, cognitive difficulties, paranoia, and anxiety. Hallucinogen Persisting Perception Disorder (HPPD) has been reported.
• Cognitive impairments: Problems with memory and concentration, especially with long-term misuse.
• Dependence and Addiction: Regular use can lead to tolerance and physical or psychological dependence, with withdrawal symptoms if use is stopped suddenly (e.g., cravings, exhaustion, anxiety, depression).
• Risk of injury: Due to diminished perception of pain and disorientation, individuals under the influence may injure themselves.

When administered in a supervised medical setting by trained professionals, ketamine is generally considered safe. Medical providers carefully screen patients for potential risks (e.g., untreated high blood pressure, certain heart conditions, history of hypersensitivity to ketamine) and monitor vital signs during treatment.

However, unsupervised or recreational use of ketamine is dangerous due to:

• Uncontrolled dosing: The risk of overdose, leading to unconsciousness, dangerously slowed breathing, seizures, or coma.
• Lack of medical monitoring: Without supervision, severe side effects like dangerously high blood pressure or respiratory depression can go unnoticed and untreated.
• Interactions with other substances: Combining ketamine with alcohol or other central nervous system depressants (like opioids) can be fatal.
• Potential for addiction and long-term health problems: Especially concerning with chronic recreational use.

Ketamine has several medical applications:

• Anesthesia: It’s widely used as an anesthetic for diagnostic and surgical procedures, especially for short procedures or as an induction agent before other general anesthetics. It’s often preferred in emergency settings due to its relatively safe profile, maintaining normal pharyngeal and laryngeal reflexes and spontaneous respiration.
• Pain Management: Ketamine is effective for treating severe pain, including trauma, fractures, and chronic pain conditions, often at lower “sub-dissociative” doses.
• Treatment-Resistant Depression and Suicidal Ideation: A specific form of ketamine, esketamine (Spravato®), is FDA-approved as a nasal spray for treatment-resistant depression when used in conjunction with an oral antidepressant. Other forms of ketamine (racemic ketamine) are used off-label for depression, anxiety, and PTSD, though more research is needed to fully understand long-term effectiveness and safety for these uses.
• Refractory Status Epilepticus: It’s also used in some cases of severe, prolonged seizures that don’t respond to other treatments.

etamine can cause a range of side effects, which can vary depending on the dose, individual sensitivity, and whether it’s used alone or with other substances.

Common short-term side effects may include:

• Disorientation, confusion, or loss of motor coordination
• Dizziness, nausea, vomiting
• Increased blood pressure, heart rate, breathing, or body temperature
• Changes in sensory perceptions, including visual or auditory hallucinations
• Feeling detached from oneself or surroundings (“dissociative experience,” or “k-hole” at higher doses)
• Blurred vision, slurred speech, drowsiness
• Numbness, feeling uncoordinated