The increasingly popular and addictive club drug ketamine, also known as “Special K” causes a variety of urinary tract problems that are more likely to occur with heavier or more frequent use, according to a new UK study. 

Researchers from the latest study, published in the British Journal of Urology International, surveyed 1,285 people who reported using ketamine in the past year, and found that 27 percent of participants had developed urinary tract problems, including abdominal pain, bladder control issues, painful urination and blood in the urine.

While in medicine ketamine is sometimes used as an anesthetic and some researchers are testing the drug as a treatment for severe depression, “Special K” is often snorted or injected by users who say that the drug can produce dream-like effects, hallucinations, and intense feelings of euphoria.

Ketamine, which has also been linked to high blood pressure, is increasingly being abused in many countries.  Repeated use has been associated with mental problems like hallucinations and impaired memory, thinking and concentration.

"The take-home message is that regular ketamine use can lead to severe urinary symptoms," lead author Angela Cottrell told Reuters.  However, researchers noted that they were unsure about how rate of urinary problems among ketamine users compares to the rate among young people in general. 

The study data was based on an online survey promoted by a UK club-music magazine called "MixMag," and of the 3,806 people who responded, 50 percent reported trying the drug at least once, and 1,285 reported that they used it in the last year. 

The findings show that the 17 percent of all participants who had symptoms of ketamine dependence, and tended to take larger doses and more often than other users, and also showed more urinary problems and abdominal pain.

Researchers said that the symptoms appeared to disappear after ketamine use stops. 

Researchers said that half of the 251 survey respondents who described their ketamine experience reported that their symptoms had improved after they stopped taking ketamine, 43 percent still had urinary problems but were also still using ketamine, and 4 percent said that their urinary problems had gotten worse even though they were off the drug.

"There may be a stage where irreversible damage may occur," Cottrell said. "However, little is known about this."