Ketamine

group of stereoisomers

Ketamine is a dissociative anesthetic. It is a type of drug a doctor might give to put someone to sleep for an operation. Ketamine can also be used as a painkiller and a bronchodilator (which makes it easier for air to get into your lungs).[1] Sometimes it can lead to a special type of hallucination which makes you feel detached from yourself and the things around you[2] which is why some people use it as a recreational drug. As it can have severe side effects, it is usually not available as an over-the-counter drug.

Ketamine

Ketamine was developed in 1962 as a rapid-acting dissociative anesthetic that was used in surgery. It was approved for human use by the Food and Drug Administration (FDA) in 1970. Unfortunately, abuse began along the West Coast and spread across the country by the 1980s. The illicit market produced new forms of the drug, available as powder, capsules, crystal rocks, tablets, and injectable solutions. The drug is largely abused intranasally (via sniffing) or orally.

Medical use change

The World Health Organization (WHO) lists ketamine as an essential medicine, especially as an anesthetic and analgesic.[3] With medical supervision, ketamine is a better surgical anesthetic than many others, and it is safer for a wider range of patients. It is also the anesthetic of choice in veterinary surgery.[4] In medicine ketamine is normally injected into a vein or muscle.[5] Ketamine is not the first anaesthetic a doctor would think of using in most situations because of the hallucinations it causes. On the other hand, while most anaesthetics suppress your breathing, resulting in the need for a machine to help you breathe, ketamine does not.[6] This can make it a useful anaesthetic when you don't have any equipment available, for example, in a war zone.[source?]

Side effects change

Short term change

Short term side effects happen in about 40% of people and include:[7]

  • Dizziness
  • Double vision
  • Euphoria
  • Blurred vision
  • Finding it hard to express emotions, not being very emotionally reactive
  • High blood pressure
  • Fast heart beat
  • Feeling sick and vomiting
  • Having trouble understanding or producing speech
  • Nightmares
  • Illusions
  • Hallucinations
  • Changed body image
  • Impaired memory and attention
  • Derealization, or losing touch with reality
  • Muscle rigidity.

Long term change

In the medical setting ketamine is only given a few times so most long term effects mentioned below are found in recreational ketamine users and animal models.[8]

Urinary tract effects change

There are 110 reports of people with problems in their urinary tract due to using ketamine.[9]

Symptoms include:

  • Urgently needing to urinate.
  • Finding it painful to urinate and having blood in your urine.
  • Not being able to hold as much urine in your bladder

These urinary tract problems are most common in people who have abused ketamine daily for a long time.[8]

Neurological effects change

People who abuse ketamine a lot (more than 4 times a week) have been found to have impaired memory and increased depression when compared to people who don't abuse ketamine. Those who use ketamine less frequently (1-4 times per week)and those who had stopped taking ketamine showed no difference in the aforementioned parameters. This suggests that these problems with memory and mood do not affect infrequent users and might be reversible once ketamine use is stopped.[10]

One study has recently been done using monkeys as a model to see if ketamine is toxic to the brain.[11] The study found that injecting the monkeys every day for 6 months with ketamine caused more cells to die in the front of their brain and also caused a decrease in activity in the areas of the brain which control movement.

Mechanism of action change

Ketamine is a NMDA antagonist in the CNS. By inhibiting NMDA receptors in inhibitiory neurons in the brain, it causes increased CNS activity and sympathomimetic effects. As a result, there is not only an anaesthetic effect, but also activation of the CNS unlike other anaesthetics. This is beneficial in surgical settings because it maintains blood pressure, airway reflexes, bronchioles remain dilated and airways patent. Making this a particularly useful drug in shock and surgery patients because of blood pressure maintained with ketamine use, unlike typical anaesthetics which cause decreased BP and respiratory suppression.

Research change

Treating addiction change

One study by Evgeny Krupitsky has found that using ketamine along with psychotherapy and group therapy was a lot more effective at treating alcohol addiction than the traditional treatment.[12] The same scientist found that ketamine might also be useful for treating heroin addiction. Patients who had been treated for their addiction with multiple sessions of ketamine fared much better than those who had only had one session of ketamine with abstinence rates of 50% and 22.2% respectively.[13]

As an antidepressant change

Some small studies have been done which found that a single dose of ketamine was able to improve treatment resistant depression after just a few hours with the effects lasting for one week.[14][15] The rapid anti-depressant effects of ketamine may prove to be a useful alternative compared to current anti-depressants which can take several weeks to have their effects.[16]

Complex regional pain syndrome change

CRPS is a disease that causes severe pain and swelling, getting worse over time.[17] Some studies have been done which suggest that ketamine might be useful as a painkiller for CRPS.[18]

References change

  1. Peck, T. E.; Hill, S. A.; Williams, M. (2008). Pharmacology for anaesthesia and intensive care (3rd ed.). Cambridge: Cambridge University Press. p. 111. ISBN 978-0-521-70463-2.
  2. Bergman, S. A. (1999). "Ketamine: review of its pharmacology and its use in pediatric anesthesia". Anesthesia Progress. 46 (1): 10–20. PMC 2148883. PMID 10551055.
  3. "Uses of Ketamine Powder as anesthetic". Trippy Way Psychedelics. Archived from the original on 2022-09-20. Retrieved 2022-09-18.
  4. "Ketamine: Medical Uses, Abuse Risks". Treatment Solutions. Retrieved 2021-09-04.
  5. Lankenau SE; Sanders B; Bloom JJ; et al. (March 2007). "First injection of ketamine among young injection drug users (IDUs) in three U.S. cities". Drug and Alcohol Dependence. 87 (2–3): 183–93. doi:10.1016/j.drugalcdep.2006.08.015. PMC 1852477. PMID 16979848.
  6. Heshmati F; Zeinali MB; Noroozinia H; Abbacivash R; Mahoori A (December 2003). "Use of ketamine in severe status asthmaticus in intensive care unit". Iranian Journal of Allergy, Asthma, and Immunology. 2 (4): 175–80. PMID 17301376.
  7. Quibell R; Prommer EE; Mihalyo M; et al. (March 2011). ""Ketamine*"". Journal of Pain and Symptom Management. 41 (3): 640–649. doi:10.1016/j.jpainsymman.2011.01.001. PMID 21419322.
  8. 8.0 8.1 Morgan, Celia J. A.; Curran, H. Valerie; Independent Scientific Committee on Drugs (1 January 2012). "Ketamine use: a review". Addiction. 107 (1): 27–38. doi:10.1111/j.1360-0443.2011.03576.x. PMID 21777321. S2CID 11064759.
  9. Middela, S.; Pearce, I. (1 January 2011). "Ketamine-induced vesicopathy: a literature review". International Journal of Clinical Practice. 65 (1): 27–30. doi:10.1111/j.1742-1241.2010.02502.x. PMID 21155941. S2CID 25034266.
  10. Morgan, Celia J. A.; Muetzelfeldt, Leslie; Curran, H. Valerie (2009). "Consequences of chronic ketamine self-administration upon neurocognitive function and psychological wellbeing: a 1-year longitudinal study". Addiction. 105 (1): 121–33. doi:10.1111/j.1360-0443.2009.02761.x. PMID 19919593.
  11. Sun, Lin; Li, Qi; Li, Qing; Zhang, Yuzhe; Liu, Dexiang; Jiang, Hong; Pan, Fang; Yew, David T. (November 2012). "Chronic ketamine exposure induces permanent impairment of brain functions in adolescent cynomolgus monkeys". Addiction Biology. 19 (2): 185–194. doi:10.1111/adb.12004. PMID 23145560. S2CID 23028521.
  12. "The Combination of Psychedelic and Aversive Approaches in Alcoholism Treatment - Eleusis". Archived from the original on 2008-06-18. Retrieved 2013-08-11.
  13. "Ketamine psychotherapy for heroin addiction" (PDF). Archived from the original (PDF) on 2013-11-01. Retrieved 2013-08-11.
  14. NIH. "Experimental Medication Kicks Depression in Hours Instead of Weeks" NIH News, 7 August 2006
  15. Khamsi, R. "Ketamine relieves depression within hours" New Scientist, 8 August 2006.
  16. Eison AS, Mullins UL (1996). "Regulation of central 5-HT2A receptors: a review of in vivo studies". Behavioural Brain Research. 73 (1–2): 177–81. doi:10.1016/0166-4328(96)00092-7. PMID 8788498. S2CID 4048975.
  17. "Firm News & Press Archive".
  18. Goldberg ME; Domsky R; Scaringe D; et al. (April 2005). "Multi-day low dose ketamine infusion for the treatment of complex regional pain syndrome". Pain Physician. 8 (2): 175–9. doi:10.36076/ppj.2005/8/175. PMID 16850072. Archived from the original on 2013-05-20. Retrieved 2013-08-11.