A new study finds that long-term regular use of the club drug ketamine, sometimes called Special K, can alter bladder function, leading to bothersome symptoms such as urgency and pelvic pain.
Symptoms may persist for up to a year or more after a person stops using ketamine, according to Dr Siu-king Mak from The Chinese University of Hong Kong and colleagues. They published their findings in the Journal of Urology.
Dr Mak said, "It is likely but not guaranteed that these early functional changes will normalise after one year of abstinence from ketamine."
Abuse of ketamine, a powerful anaesthetic, is on the rise in many countries. Repeated use has been linked to mental problems such as hallucinations and impaired memory, thinking and concentration. It also causes high blood pressure.
Incontinence and drug abuse
In the last three years, at least five reports have "alerted the urological community to the spectrum" of lower urinary tract symptoms associated with regular recreational ketamine use, Dr Mak and colleagues note in their report.
These include painful urination, debilitating urinary frequency, urgency, urge incontinence and blood in the urine, often with inflammation and abnormal blood vessel growth in the bladder.
The authors say that to the best of their knowledge their study is the first report of lower urinary tract status in teenagers and young adults in the general population using ketamine.
They surveyed 66 individuals between 13 and 25 years old with a history of ketamine use. Roughly three-quarters were male. Lower urinary tract function was evaluated using a "Pelvic Pain, Urgency and Frequency (PUF) Questionnaire", as well as sonograms and measures of urinary flow.
At the time of questioning, 36 subjects were currently using ketamine and 31 provided information on the duration of their ketamine use. Of these, 26% had been using for more than four years, 36% for between two and four years, 32% for one to two years and only 6% for less than one year.
The active ketamine users used an average of 12.5 grams per week, with wide variation and a maximum weekly use of 64 grams.
People should be made aware of risks
They found that use of ketamine three or more times a week was associated with "measurable dysfunction of the (lower urinary tract)". In particular, this level of use was significantly tied with lower urine output volumes.
"This is the first report showing the dose relation of ketamine abuse and deterioration of bladder function," Dr Mak said.
"This evidence should be conveyed to young adults abusing ketamine and to the general public. The potential side effects on the lower urinary tract should be mentioned to chronic pain patients using ketamine," Dr Mak added.
Previous ketamine users in the study who had abstained from the drug for more than a year tended to have higher voided volumes than active ketamine users or those who had abstained for three months.
Ultrasound showed kidney swelling in 25 percent of active ketamine users versus 5 percent of nonusers. Abdominal pain was reported by nine users and two abstainers. No subjects reported incontinence. Blood in the urine was noted in three active users and two nonusers.
Scores on the PUF questionnaire were significantly higher (worse) for subjects who used ketamine for more than two years compared to those who used it for shorter durations. The scores got progressively better with increased duration of abstinence.
For individuals with one year of abstinence, the PUF questionnaire scores were significantly lower (better) and urine output volumes were higher than those for active users. Summing up, the researchers say it has become clear that regular use of ketamine for long periods of time will have adverse effects on physical and mental health.
"This study provides a basis for the development of health promotion material that can be used in the community by welfare workers seeking to encourage drug cessation," Dr Mak and colleagues note in their report.
(Reuters Health, Megan Brooks, July 2011)
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