Ketamine (Ketalar, Vetalar, Ketaset) by Ray Sahelian, M.D. Use and abuse

Ketamine is an anesthetic most commonly used on animals but also used in humans. Ketamine, sometimes called Special K on the street, is an anesthetic that is available only to physicians and is a scheduled drug. The liquid form of ketamine is injected either IV or IM. This drug is a potent NMDA antagonist.

Ketamine and depression
Ketamine causes feelings of detachment and relaxation. It helps restores to normal the orbifrontal cortex, an area of the brain located above the eyes that is overactive in depressed people. The orbifrontal cortex is believed to be responsible for feelings of guilt, dread, apprehension and physical reactions such as a racing heart. It may also be an area that holds grudges. Some ketamine reseachers think that this drug could be useful to treat depression. For natural ways to treat this mood disorder, see depression.
 

Ketamine Abuse
Ketamine has become popular among teens and young adults at dance clubs and raves.

Cognitive decline, memory problems
Abuse of ketamine impairs memory, concentration, and psychological well-being. Dr. Celia J. A. Morgan and colleagues, from University College London, followed 150 people for over 1 year to assess how use of the drug affects memory, concentration, and psychological well-being. The subjects were evenly divided into five groups based on their usage of ketamine: nearly daily use in large quantities (frequent use), use once or twice a month (recreational use), former use, use of illicit drugs other than ketamine, and no use of any illicit drugs. Impairments in thinking ability and psychological well-being were mostly seen in frequent users. Moreover, as the study year progressed, short term memory and visual memory continued to worsen in this group. Frequent ketamine users also had disturbances in verbal memory, such as forgetfulness and difficulty in recalling people's names or conversations. By contrast, recreational ketamine users and former users did not show disturbances in memory, attention, or most tests of psychological well-being, suggesting that occasional use does not cause lasting damage and that the impairments seen may be reversible when usage is stopped. This study by Dr. Celia J. A. Morgan was published in Addiction, November 16th online issue, 2009.

Ketamine abuse and urinary problems, interstitial cystitis
Ketamine may cause inflammation and contraction of the bladder leading to possibly irreversible kidney damage. Dr. Peggy Sau-Kwan Chu from Tuen Mun Hospital, Hong Kong, China evaulated 59 ketamine abusers who were seen at Hong Kong hospitals from March 2000 to December 2007. All of the ketamine users had moderate to severe lower urinary tract symptoms, such as urgency, frequency, and difficulty urinating. Visual examination with a cystoscope revealed an inflamed bladder in 42 of these individuals, and biopsies showed that 12 of them had a more serious condition called interstitial cystitis. On further testing, 47 patients were found to have overactive bladder or decreased bladder elasticity. BJU International, 2008.

Ketamine and Altered State of Consciousness

Ketamine is also used by certain individuals as a way to relax and heal old wounds and find answers to one's life uncertainties. The dose of ketamine used for this manner is usually a tenth or less of the dose used for anesthesia.

Ketamine and Near Death Experience
Ketamine HCL, when injected IM or IV, is able to induce a near death experience. Since high levels of ketamine can cause complete anesthesia, the dose required to have an experience is a tenth smaller than what is given by veterinarians and physicians.

Ketamine for Depression
A single dose of the anesthetic ketamine appears to reduce depression in patients who show little improvement with standard medications, new research suggests. The beneficial effects start less than 2 hours after the drug is given and last for about 7 days, according to results of a study conducted by investigators at the National Institutes of Health in Bethesda, Maryland. The researchers decided to look at ketamine as a treatment because it blocks an enzyme system that seems to play a key role in depression. Their study group included 17 patients with severe depression that failed to respond to at least two trials of antidepressants. They were required to have a score of at least 18 on a standard depression test called the Hamilton Depression Rating Scale (HDRS). In the trial, the participants received an intravenous infusion of ketamine or inactive "placebo," then switched to an infusion of the other agent 1 week later. Patients treated with ketamine scored significantly lower on the HDRS at 110 minutes, lasting through 7 days, compared with those receiving placebo treatment. The HDRS at day 1 fell by up to 90 percent, indicating a substantial improvement in depression. Seventy-one percent of patients were classified as treatment responders and 29 percent had little or no evidence of depression on day 1 after the ketamine dose. The treatment response was maintained for at least 1 week by 35 percent of patients. Archives of General Psychiatry, August 2006.

Q. I am a patient of depression since 12 years now and none of the anti-depressants have worked. I recently learnt about how small doses of ketamine (0.5 mg/kg IBW) can lead to tremendous improvement in depression. So I decided to try it and it worked! I have never felt this better. I take about 30mg of ketamine orally. Is it okay to take this much daily? I have read that use can cause bladder problems, but none of those research papers seem to mention the dosage of ketamine which is potentially harmful. So my basic question is - is a 30mg dose safe for daily use?
   A. I am not familiar with its regular use and how safe it is if used daily.

Pain treatment
Outpatient infusions can significantly improve the severe pain of complex regional pain syndrome, a chronic problem after trauma. Dr. Robert J. Schwartzman from Drexel University College of Medicine, Philadelphia, wanted to find a ketamine regimen that could potentially achieve the complete, long-lasting remissions seen with multiple days of anesthetic doses, but with sub-anesthetic doses in outpatients. Dr. Robert J. Schwartzman reports on 19 patients with severe, long-standing complex regional pain syndrome who were randomized to receive 4-hour infusions of ketamine (25 mL/h) or placebo each day for 10 days, with a limit of 25 mg/h over 4 hours. All subjects also received clonidine and midazolam. Ketamine produced improvements on scores for a 7-question pain questionnaire and on the short form McGill pain questionnaire. Pain 2009;147:107-115.