Ketamine

Ketamine was developed in the early 1960s to be used as a sedative in the human and veterinary medicine. It was created by Dr. Calvin Stevens of Wayne State University, and then developed by Parke-Davis in 1962 as an alternative to the anesthetic drug Phencyclidine (PCP). Apart from a veterinary medicine, Ketamine is also used as a battlefield anesthetic in the developing nations. The hydrochloride salt of Ketamine is sold as Ketanest, Ketaset, and Ketalar. Over the years, Ketamine has become a popular party-drug due to its trance-like effects, or “dissociative anesthesia”.

Ketamine was developed as an alternative to PCP because PCP was more likely to cause hallucinations, seizures, and neurotoxicity. It is pharmacologically classified as an NMDA receptor antagonist. When used in high anesthetic doses, Ketamine binds to opioid μ receptors and sigma receptors.

Ketamine is a chiral compound and majority of the pharmaceutical preparations are racemic in nature. Chemically, a racemic mixture has equal amounts of left and right handed enantiomers of a chiral molecule. In the World Health Organization’s “Essential Drugs List”, Ketamine is a “core” medicine, needed for the basic health care system. The most active enantiomer, S-ketamine, is used medically under the brand name Ketanest S. Ketamine’s psychotomimetic effects give it the potential to cause the emergence phenomena.

Medically, Ketamine is injected intravenously or intramuscularly. However, it is also effective when smoked, taken orally, or insufflated. Ketamine does not suppress breathing unlike other anesthetics, but it does cause severe hallucinations and this is a major reason why it is not used on patients with unknown medical history (like accident victims). Ketamine is used in podiatry, minor surgery, and the treatment of migraine. A research is being conducted to ascertain the effects of Ketamine in pain therapy, as an antidepressant, and in the treatment of alcoholism and heroin addiction. Cats, dogs, rabbits, rats and several other small animals are administered Ketamine to induce anesthesia in them. In larger animals, Ketamine works to control pain.

As a local anesthesia administered to relieve neuropathic pain, or pain associated with movement, 0.1−0.5mg/kg/h of Ketamine is sufficient. Such doses undermine the psychotropic side effects and also counteract spinal sensitization. Being a co-analgesic, Ketamine is most effective when used along with an opioid, and proves particularly helpful in relieving pain caused by cancer.

Respiratory and circulatory systems react favorably to Ketamine in comparison to other anesthetics. In anesthetic doses, Ketamine stimulates the circulatory system and at times Ketamine anesthesia can be performed without protection of the airways. It is only because of its psychotropic and unwanted psychological effects that the use of Ketamine in human medicine has taken a backseat. However, these side effects can be considerably reduced or totally done away with by the simultaneous use of the benzodiazepine sedative.

Ketamine infusion has proved effective in curing depression in patients suffering from complex regional pain syndrome. Though never documented properly, it is believed that a low dose or subanesthetic infusion of Ketamine might work in people suffering primarily from treatment-resistant depression.

Even in people suffering from chronic pain along with sensory, autonomic, motor and dystrophic symptoms (complex regional pain syndrome), Ketamine is observed to have a positive effect. This may be possible because Ketamine manipulates NMDA receptors, thereby rebooting aberrant brain activity. The “Awake” technique is one in which a low dose (25−90mg per day) of Ketamine is infused in the patient over a period of 5−10 days. This is noted to have significantly reduced the pain, decreased autonomic dysregulation, and increased mobility. The other treatment procedure consists of medically inducing coma in the patient and giving him/ her an extremely high dose (600−900mg) of Ketamine. This method has succeeded in curing the complex regional pain, or at least keeping it in remission.

Ketamine is also proved to have positive effects on people suffering from alcoholic addiction. This method combines psychedelic and aversive techniques, and involves controlled Ketamine use, psychotherapy and group therapy. This technique was first used by the Russian doctor Evgeny Krupitsky (Clinical Director of Research for the Saint Petersburg Regional Center for Research in Addiction and Psychopharmacology), and has proved very effective in a large percentage of alcoholic males. Heroin addicts have also been treated in a similar manner and it has been noted that one Ketamine assisted psychotherapy session is more effective than active placebo. This method promotes heroin abstinence without any adverse reactions.

Ketamine can produce the positive symptoms (hallucinations, delusions), negative symptoms (social withdrawal, alogia), and the cognitive deficits of schizophrenia in humans and animals. It is the ideal pharmacological model of schizophrenia and has led to the formation of the alternative theory which states that schizophrenia is a result of the hypofunction of the NMDA receptor in the prefrontal cortex.

Though Ketamine has proved very useful drug in the medical world, its side effects have made it a popular dissociative. The unusual phenomenology of Ketamine intoxication has been documented in John Lilly’s “The Scientist” and Marcia Moore and Howard Alltounian’s “Journeys into the Bright World”. It was used for recreational purposes in rave parties which prompted the US government to place it in the schedule of the Controlled Substance Act in 1999. Ketamine was outlawed in the United Kingdom, and Canada classified it as a Schedule I narcotic. Even in some eastern countries, Ketamine has been placed under the dangerous drugs ordinance. It can be used legally only by health professionals, for research purposes, or with a relevant medical prescription.

On the streets, Ketamine is referred to as cat valium, K, Ket, new ecstasy, super acid, and vitamin K. As a party drug, it is used more commonly as a liquid, but can also be taken in the form of powder or caplets. The liquid Ketamine is injected into muscles, snorted, smoked, rolled into joints, or even mixed in drinks. Ketamine generally induces a dream-like state and hallucinations, and in larger doses, it can cause amnesia, delirium, impaired motor functions, depression, high blood pressure, eventually leading to fatal respiratory problems. In the long term, Ketamine can lead to addiction and paranoia, and has also acquired the reputation of a date-rape drug.