Ketamine

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Ketamine

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.

Medical use[change | change source]

In medicine ketamine is normally injected into a vein or muscle.[3] 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.[4] 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 | change source]

Short term[change | change source]

Short term side effects happen in about 40% of people and include:[5]

  • 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.

Long term[change | change source]

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.[6]

Urinary tract effects[change | change source]

There are 110 reports of people with problems in their urinary tract due to using ketamine.[7]

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.[6]

Neurological effects[change | change source]

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.[8]

One study has recently been done using monkeys as a model to see if ketamine is toxic to the brain.[9] 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 | change source]

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 | change source]

Treating addiction[change | change source]

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.[10] 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.[11]

As an antidepressant[change | change source]

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.[12][13] 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.[14]

Complex regional pain syndrome[change | change source]

CRPS is a disease that causes severe pain and swelling, getting worse over time.[15] Some studies have been done which suggest that ketamine might be useful as a painkiller for CRPS.[16]

References[change | change source]

  1. Peck, T. E.; Hill, S. A.; Williams, M. (2008). Pharmacology for anaesthesia and intensive care (3rd edition). 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. 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.
  4. 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.
  5. 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.
  6. 6.0 6.1 Morgan, Celia J. A.; Curran, H. Valerie (1 January 2012). "Ketamine use: a review". Addiction 107 (1): 27–38. doi:10.1111/j.1360-0443.2011.03576.x. PMID 21777321.
  7. 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.
  8. 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.
  9. Sun, Lin; Qi Li, Qing Li, Yuzhe Zhang, Dexiang Liu, Hong Jiang, Fang Pan, David T. Yew (November 2012). "Chronic ketamine exposure induces permanent impairment of brain functions in adolescent cynomolgus monkeys". Addiction Biology. doi:10.1111/adb.12004. PMID 23145560. http://onlinelibrary.wiley.com/doi/10.1111/adb.12004/abstract.
  10. The Combination of Psychedelic and Aversive Approaches in Alcoholism Treatment - Eleusis
  11. http://www.eleusis.us/resource-center/references/ketamine-psychotherapy-heroin.pdf
  12. NIH. "Experimental Medication Kicks Depression in Hours Instead of Weeks" NIH News, 7 August 2006
  13. Khamsi, R. "Ketamine relieves depression within hours" New Scientist, 8 August 2006.
  14. 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.
  15. http://www.marksandharrison.com/pdf/CRPS.pdf
  16. 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. PMID 16850072. http://www.painphysicianjournal.com/linkout_vw.php?issn=1533-3159&vol=8&page=175.