ketamine ketamine ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. it is also used as a treatment for depression, a pain management tool, and as a recreational drug. ketamine is a novel compound that was derived from phencyclidine in 1962, in pursuit of a safer anesthetic with fewer hallucinogenic effects. ketamineclinical datatrade namesketalar, othersother namesci-581; cl-369; cm-52372-2ahfs/drugs.commonographlicense data us dailymed: ketamine us fda: ketamine pregnancycategory au: b3 addictionliabilitylow–moderate routes ofadministrationanydrug classnmda receptor antagonists; general anesthetics; dissociative hallucinogens; analgesics; antidepressantsatc coden01ax03 (who) legal statuslegal status au: s8 (controlled drug) br: class c1 (other controlled substances) ca: schedule i de: unscheduled uk: class b us: schedule iii un: unscheduled in general: ℞ (prescription only) pharmacokinetic databioavailability intravenous: 100% intramuscular: 93% subcutaneous: high epidural: 77% intranasal: 45–50% sublingual: 24–30% rectal: 25–30% by mouth: 16–20% protein binding23 to 47%.metabolismliver, intestine (oral): major: cyp3a4, cyp2b6 metabolites norketamine dehydronorketamine hydroxynorketamine onset of action intravenous: seconds intramuscular: 1–5 min subcutaneous: 15–30 min insufflation: 5–10 min by mouth: 15–30 min elimination half-life ketamine: 2.5–3 hours norketamine: 12 hours duration of action intramuscular: 0.5–2 hours insufflation: 45–60 min by mouth: 1–6+ hours excretion urine: 91% feces: 3% identifiers iupac name (rs)-2-(2-chlorophenyl)-2-(methylamino)cyclohexanone cas number6740-88-1 y 33643-46-8 (esketamine) 33643-49-1 (arketamine) hcl: 1867-66-9 ypubchem cid3821iuphar/bps4233drugbankdb01221 ychemspider3689 yunii690g0d6v8hkeggd08098 yhcl: d00711 ychebichebi:6121 ychemblchembl742 ycomptox dashboard (epa)dtxsid8023187 echa infocard100.027.095 chemical and physical dataformulac13h16clnomolar mass237.73 g·mol−13d model (jsmol)interactive imagechiralityracemic mixture: esketamine (s(+)-isomer) arketamine (r(−)-isomer) melting point92 °c (198 °f) smiles clc1ccccc1c2(nc)ccccc2=o inchi inchi=1s/c13h16clno/c1-15-13(9-5-4-8-12(13)16)10-6-2-3-7-11(10)14/h2-3,6-7,15h,4-5,8-9h2,1h3 ykey:yqezlkzalyswhr-uhfffaoysa-n y (verify) at anesthetic doses, ketamine induces a state of "dissociative anesthesia", a trance-like state providing pain relief, sedation, and amnesia. the distinguishing features of ketamine anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilation. at lower, sub-anesthetic doses, ketamine is a promising agent for pain and treatment-resistant depression. however, as with many antidepressants, the results of a single administration of ketamine wane with time. the long-term effects of repeated use are largely unknown, and are an area of active investigation. liver and urinary toxicity have been reported among regular users of high doses of ketamine for recreational purposes. ketamine is an nmda receptor pore blocker and that accounts for most of its actions, except the antidepressant effect, the mechanism of which is a matter of much research and debate. ketamine was first synthesized in 1962 and approved for use in the united states in 1970. it has been regularly used in veterinary medicine and was extensively used for surgical anaesthesia in the vietnam war. along with other psychotropic drugs, it is on the world health organization's list of essential medicines. it is available as a generic medication. when used as a recreational drug, it is found both in powder and liquid form, and is often referred to as "special k" for its hallucinogenic and dissociative effects. medical uses anesthesia the use of ketamine in anesthesia reflects its characteristics. it is a drug of choice for short-term procedures when muscle relaxation is not required. the effect of ketamine on the respiratory and circulatory systems is different from that of other anesthetics. it suppresses breathing much less than most other available anesthetics. when used at anesthetic doses, ketamine usually stimulates rather than depresses the circulatory system. protective airway reflexes are preserved and it is sometimes possible to administer ketamine anesthesia without protective measures to the airways. psychotomimetic effects limit the acceptance of ketamine; however, lamotrigine and nimodipine decrease psychotomimetic effects and can be counteracted also by benzodiazepines administered or propofol. ketamine is frequently used in severely injured people and appears to be safe in this group. it has been widely used for emergency surgery in field conditions in war zones, for example, during the vietnam war. a 2011 clinical practice guideline supports the use of ketamine as a sedative in emergency medicine, including during physically painful procedures. it is the drug of choice for people in traumatic shock who are at risk of hypotension. low blood pressure is dangerous for people with severe head injury and ketamine is unlikely to lower blood pressure — conversely, often raising blood pressure, making it often the best suited for those with severe head injury. ketamine is an option in children, as the sole anesthetic for minor procedures or as an induction agent followed by neuromuscular blocker and tracheal intubation in particular, children with cyanotic heart disease and neuromuscular disorders are good candidates for ketamine anesthesia. due to the bronchodilating properties of ketamine, it can be used for anesthesia in people with asthma, chronic obstructive airway disease, and with severe reactive airway disease including active bronchospasm. pain ketamine infusions are used for acute pain treatment in emergency departments and in the perioperative period in individuals with refractory pain. the doses are lower than those used for anesthesia; they are usually referred to as sub-anesthetic doses. adjunctive to morphine or on its own, ketamine reduces morphine use, pain level, nausea, and vomiting after surgery. ketamine is likely to be most beneficial for surgical patients when severe post-operative pain is expected and for opioid-tolerant patients. ketamine is especially useful in the prehospital setting, due to its effectiveness and low risk of respiratory depression. ketamine has similar efficacy to opioids in a hospital emergency department setting for management of acute pain and for control of procedural pain. it may also prevent opioid-induced hyperalgesia and postanesthetic shivering. for chronic pain, ketamine is used as an intravenous analgesic, particularly, if the pain is neuropathic. it has the added benefit of counteracting spinal sensitization or wind-up phenomena experienced with chronic pain. in multiple clinical trials, ketamine infusions delivered short-term pain relief in neuropathic pain diagnoses, pain after traumatic spine injury, fibromyalgia, and complex regional pain syndrome (crps). however, the 2018 consensus guidelines on chronic pain concluded that, overall, there is only weak evidence in favor of ketamine use in spinal injury pain, moderate evidence in favor of ketamine for crps, and weak or no evidence for ketamine in mixed neuropathic pain, fibromyalgia, and cancer pain. in particular, only for crps there is evidence of medium to longer term pain relief. depression