Ketamine

K-holeSpecial KCalypsolhorse tranquilliserKKetalarketaminKetasetRecreational use of ketaminetranquilizer
Ketamine is a medication mainly used for starting and maintaining anesthesia.wikipedia
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WHO Model List of Essential Medicines

World Health Organization's List of Essential MedicinesList of Essential MedicinesModel List of Essential Medicines
It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.

NMDA receptor antagonist

NMDA antagonistNMDA antagonistsNMDA receptor antagonists
Ketamine is an NMDA receptor antagonist, but it may also have other actions.
Some NMDA receptor antagonists, such as ketamine, dextromethorphan (DXM), phencyclidine (PCP), methoxetamine (MXE), and nitrous oxide (N 2 O), are popular recreational drugs used for their dissociative, hallucinogenic, and euphoriant properties.

Sedation

sedatedsedatingsedate
It induces a trance-like state while providing pain relief, sedation, and memory loss.
Examples of drugs which can be used for sedation include isoflurane, diethyl ether propofol, etomidate, ketamine, fentanyl, pentobarbital, lorazepam and midazolam.

Analgesic

analgesiaanalgesicspainkillers
It induces a trance-like state while providing pain relief, sedation, and memory loss.
Other psychotropic analgesic agents include ketamine (an NMDA receptor antagonist), clonidine and other α 2 -adrenoreceptor agonists, and mexiletine and other local anaesthetic analogues.

Opioid

opioidsopioid-induced constipationopioid analgesic
Ketamine is an analgesic that is most effective when used alongside a low-dose opioid; because, while it does have analgesic effects by itself, the doses required for adequate pain relief when it is used as the sole analgesic agent are considerably higher and far more likely to produce disorienting side effects.

Hallucinogen

hallucinogenicpsychedelic drughallucinogens
Ketamine is also used as a recreational drug for its hallucinogenic and dissociative effects. Ketamine can produce euphoria and dissociative hallucinogen effects at higher doses, and thus has an abuse potential.
The classical dissociatives achieve their effect through blocking the signals received by the NMDA receptor set (NMDA receptor antagonism) and include ketamine, methoxetamine (MXE), phencyclidine (PCP), dextromethorphan (DXM), and nitrous oxide.

Recreational drug use

recreational drugdrug userecreational drugs
Ketamine is also used as a recreational drug for its hallucinogenic and dissociative effects.

Esketamine

Spravato
Ketamine has not been approved for use as an antidepressant, but its enantiomer, esketamine, was developed as a nasal spray for treatment-resistant depression and was approved for this indication in the United States in March 2019. Esketamine is a more potent NMDA receptor antagonist and dissociative hallucinogen than arketamine, the other enantiomer of ketamine.
The compound is the S enantiomer of ketamine, which is an anesthetic and dissociative similarly.

Psychoactive drug

psychoactivepsychotropicdrug
At these doses, the psychotropic side effects are less apparent and well managed with benzodiazepines.
For example, propofol is a GABA agonist, and ketamine is an NMDA receptor antagonist.

Anesthesia

anaesthesiaanestheticanesthetized
Ketamine is a medication mainly used for starting and maintaining anesthesia.
Many drugs can produce a sedative effect including benzodiazepines, propofol, thiopental, ketamine and inhaled general anesthetics.

Morphine

morphiamorphine addictionmorphine sulfate
Low doses of ketamine may reduce morphine use, nausea, and vomiting after surgery.
The effects of morphine can be countered with opioid receptor antagonists such as naloxone and naltrexone; the development of tolerance to morphine may be inhibited by NMDA receptor antagonists such as ketamine or dextromethorphan.

Trance

trance statesystemic trancetrance states
It induces a trance-like state while providing pain relief, sedation, and memory loss.

Dissociative

dissociative anestheticdissociativesDissociative drug
Ketamine is also used as a recreational drug for its hallucinogenic and dissociative effects. Ketamine can produce euphoria and dissociative hallucinogen effects at higher doses, and thus has an abuse potential.
Both Pender (1970) and Johnstone et al. (1959) reported that patients under anaesthesia due to either ketamine or phencyclidine were prone to purposeless movements and had hallucinations (or "dreams" ) during and after anaesthesia.

Olney's lesions

neurotoxicityNMDA Antagonist NeurotoxicityNMDA receptor antagonist neurotoxicity
In 1989, psychiatry professor John Olney reported ketamine caused irreversible changes, known as Olney's lesions, in two small areas of the rat brain.
In 1989, Olney et al. discovered that neuronal vacuolation and other cytotoxic changes ("lesions") occurred in brains of rats administered NMDA antagonists, including PCP, MK-801 (dizocilpine) and ketamine.

Dehydronorketamine

Active metabolites of ketamine including dehydronorketamine, hydroxynorketamine, and norketamine have been found to act as negative allosteric modulators of the α 7 nicotinic acetylcholine receptor in the KXa7R1 cell line (HEK293 cells transfected with rat nicotinic acetylcholine receptor genes) with subanesthetic and nanomolar potencies (e.g., IC 50 = 55 nM for dehydronorketamine), whereas ketamine itself was inactive at the same concentrations (< 1 μM).
Dehydronorketamine (DHNK), or 5,6-dehydronorketamine, is a minor metabolite of ketamine which is formed by dehydrogenation of its metabolite norketamine.

Norketamine

Active metabolites of ketamine including dehydronorketamine, hydroxynorketamine, and norketamine have been found to act as negative allosteric modulators of the α 7 nicotinic acetylcholine receptor in the KXa7R1 cell line (HEK293 cells transfected with rat nicotinic acetylcholine receptor genes) with subanesthetic and nanomolar potencies (e.g., IC 50 = 55 nM for dehydronorketamine), whereas ketamine itself was inactive at the same concentrations (< 1 μM).
Norketamine, or N-desmethylketamine, is the major active metabolite of ketamine, which is formed mainly by CYP3A4.

Nystagmus

nystagmus, pathologicPathologic nystagmusHorizontal gaze nystagmus

Euphoria

euphoriceuphorianthigh
Ketamine can produce euphoria and dissociative hallucinogen effects at higher doses, and thus has an abuse potential.
Certain depressants can produce euphoria; some of the euphoriant drugs in this class include alcohol in moderate doses, γ-hydroxybutyric acid, and ketamine.

Dizocilpine

MK-801(+)-MK-801[ 3 H]MK801
It binds specifically to the dizocilpine (MK-801) site of the NMDA receptor, near the channel pore, and is an uncompetitive antagonist.
Because of these effects of dizocilpine, the NMDA receptor pore-blocker ketamine is used instead as a dissociative anesthetic in human medical procedures.

NMDA receptor

NMDANMDARNMDA receptors
In vitro, ketamine acts as a selective antagonist of the NMDA receptor, an ionotropic glutamate receptor.
The anaesthetic and analgesic effects of the drugs ketamine and nitrous oxide are partially because of their effects on NMDA receptor activity.

CYP2B6

2B6CYP2B6 inhibitors
Plasma concentrations of ketamine are increased by CYP3A4 inhibitors (e.g., diazepam) and CYP2B6 inhibitors (e.g., orphenadrine) due to inhibition of its metabolism.

Complex regional pain syndrome

reflex sympathetic dystrophyCausalgiaReflex neurovascular dystrophy
Low-dose ketamine is sometimes used in the treatment of complex regional pain syndrome (CRPS).
Tentative evidence supports the use of bisphosphonates, calcitonin, and ketamine.

Substance abuse

drug abusedrug useabuse
Ketamine can produce euphoria and dissociative hallucinogen effects at higher doses, and thus has an abuse potential.

Arketamine

Esketamine is a more potent NMDA receptor antagonist and dissociative hallucinogen than arketamine, the other enantiomer of ketamine.
Arketamine (developmental code names PCN-101, HR-071603), also known as (R)-ketamine or (R)-(−)-ketamine, is the (R)-(−) enantiomer of ketamine.

Intraocular pressure

intra-ocular pressurepressure inside the eyepressure in the eye
Ketamine also increases IOP.