Ketamine is a dissociative anaesthetic, meaning users will feel detached from themselves and their immediate surroundings. The drug also has painkilling, stimulant and psychedelic effects. Effects are immediate if injected, though this practice is rarer, with most users sniffing the drug. Using the drug this way, the effects will take around 20 minutes to come on, and can last for one or two hours.
The drug is described as dose specific. This means the amount taken will strongly determine the extent and type of effect the drug will have. At a relatively low dosage (around 100mg), users will commonly experience mild dissociative effects, hallucinations, and will feel distortions of time and space.
In 1992 it found its way on to the club and rave scene in the UK when people took it thinking they were buying ecstasy. Ketamine comes in a variety of forms, ranging from its liquid pharmaceutical state, for injecting, through to pill to be taken orally. Powders are sniffed up the nose or sometimes smoked.
Larger doses (anything above 200mg) may induce a so called ‘K-hole’, where a user can experience considerable and lengthy detachment from reality. The user may experience hallucinations, followed by numbness, often in the limbs, and strange muscle movements. Users may also feel sick or throw up – which can be very dangerous at high doses if the user is unconscious or very disorientated as people may choke on their vomit.
Concerns over the risks of using the drug have been growing in recent years. Repeated or heavy use of ketamine appears to be particularly harmful to the urinary tract and can cause ulcerative cystitis, where the bladder wall thickens. In some cases, individuals have had to have their bladders surgically removed. Frequent use can also cause kidney dysfunction and abdominal pains known as ‘K-cramps’.
The risk of death from accidents is also elevated while under the influence of ketamine. As a powerful anasthetic, ketamine use can make users more vulnerable to physical injury as the seriousness of an incident may not be immediately apparent. Its dissociative effects may also make users unaware of potentially risky behaviour. One study found that as many as 83% of ketamine users knew of someone who had an accident from taking ketamine.
Frequent use of ketamine may also lead to depression.
While the evidence is still unclear, there is strong evidence from ketamine users that heavy use of the drug can lead to dependence. Studies on animals, as well as reports from regular users, suggest that tolerance to ketamine can also develop, with heavy use precipitating higher dosages to achieve similar effects.
Ketamine use can also be particularly dangerous if used at the same time as depressant drugs such as alcohol, heroin or tranquillisers, with the combined effects of the depressant drugs causing the body to shut down to such an extent that the lungs or heart may stop functioning.
According to data from the 2010/2011 British Crime Survey (BCS) published by the Home Office, around 714,000 16 to 59-year-olds are estimated to have taken ketamine in their lifetime, and 207,000 in the last year. The drug appears to be particularly prevalent amongst young people, with 66 per cent of those who admitted taking the drug in the last year being 16 to 24-year-olds. The data for 2010/11 showed that use in the 16 to 24 age group had almost doubled since the drug was brought under control of the Misuse of Drugs Act in 2006. An estimated 0.8 per cent of 16 to 24-year-olds had taken it in the last month in 2006/07. This had risen to 2.1 per cent by 2010/11. A 2009 survey in the specialist clubbing magazine Mixmag suggested that as many as 68 per cent of clubbers had tried the drug.