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 the lungs). In some countries it is used as an analgesic, for fast pain relief such as in bone fractures and in children. It has been or is starting to be used for pain relief both as a replacement for or use with opiates such as morphine with varing success.

It can lead to side effects when used medically. The profile of these side effects are generally the opposite of morphine, but the dose of ketamine is lower than a recreational dose and it is not usually enough to cause a high. Sometimes it can lead to a special type of hallucination which makes people feel detached, 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 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 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  by sniffing or by mouth.

## Medical use

The World Health Organization  lists ketamine as an essential medicine, especially as an anesthetic and analgesic. With medical supervision, ketamine is a better surgical anesthetic than many others, and it is safer for a wider range of patients such as opiate tolerant ones. It is also the anesthetic of choice in veterinary surgery. In medicine ketamine is normally injected into a vein or muscle. Most anaesthetics suppress breathing, resulting in the need for a machine to help breathing. Ketamine does not.This can make it a useful anaesthetic if there is no equipment available, for example, in a war zone.

### Short term

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

- 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

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.

#### Urinary tract effects

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

Symptoms include:

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

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

#### Neurological effects

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. This suggests that these problems with memory and mood do not affect infrequent users and might be reversible once ketamine use is stopped.

A study (from 2012) used monkeys as a model to see if ketamine is toxic to the brain.
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.

### Treating addiction

One study by Evgeny Krupitsky found that using ketamine along with psychotherapy and group therapy was a lot more effective at treating alcohol addiction than the traditional treatment. He 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.

### As an antidepressant

Some 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. 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.    Ketamine-assisted psychotherapy has become popular.

### Complex regional pain syndrome

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