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Long-term users of ketamine warned of serious health risks

Bladder problems and neurological damage key side effects

Caroline White

Thursday, 21 July 2011

Long term users of ketamine— now the fourth most popular recreational drug used by clubbers in the UK—risk serious bladder and memory problems, concludes the most comprehensive review to date of the drug.

Ketamine, which is used for anaesthesia and pain relief by both doctors and veterinarians, is currently classified as a class C drug. But the review authors suggest that it is potentially more harmful than other drugs such as cannabis (class B) or ecstasy (class A).

The review, published in the journal Addiction, and carried out on behalf of the Independent Scientific Committee on Drugs (ISCD), was prompted by widespread misunderstanding about the potential harms of the drug.

Dr Celia Morgan and Professor Val Curran of the Clinical Psychopharmacology Unit at University College London systematically reviewed existing data on the drug, including their own original research, dating back over the past 11 years.

Their analysis shows that ketamine is not only addictive, but that frequent use of the drug is associated with ketamine-induced ulcerative cystitis otherwise known as “K-bladder”. In some cases this can result in a young person’s bladder being surgically removed, say the authors. Daily use of ketamine also seriously impairs short and long term memory.

And the drug can be addictive, say the authors, adding that frequent users often fail to give it up, despite repeated efforts to do so. “Anecdotally, we have encountered many frequent users who have difficulties stopping the drug and yet cannot gain access to drug treatment services in the UK,” they write.

Professor Val Curran comments: “It is vital that ketamine users and professionals have access to accurate information on ketamine use to reduce its potential harms. With only one facility offering treatment specifically for ketamine addiction in the whole of London, there is an urgent need for an increase in addiction services nationwide for ketamine users, linking these with urological clinics and reviewing the effectiveness of classification as a means of reducing drug harms.”

In the UK, ketamine was classified as a Class C substance in 2006. According to an annual drugs survey, the average price of a gram of ketamine in the UK fell from £30 to £20 between 2005 and 2008 and has since become cheaper still.

Ketamine has been included in the British Crime Survey (BCS) since 2006 and the estimated number of ketamine users has risen from around 85,000 in 2006/2007 to 113,000 in 2008/2009. Similarly, a survey of clubbers in 2001 found that one in four respondents had taken ketamine; a similar survey in 2009 found this had increased to 68%.

Although the authors point out that ketamine’s current classification under the Misuse of Drugs Act does not reflect its known and potentially severe harms, they caution: “At the same time, there is currently little evidence that changing a drug’s legal classification impacts on drug users’ behaviour.”

But they urge clinicians to warn young people of the risks they might be taking.

“Young people should be made aware of the long term physical risks of using ketamine. Ulcerative cystitis and loss of bladder control do not mesh well with desirable images of being young and attractive, and so a harm reduction message could be constructed,” they write.

And they add: “The long term neurological, neurocognitive and psychiatric effects must be further investigated in longitudinal studies, which must also follow up on those who subsequently stop using ketamine.”

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