Public Health England has expressed concern that increasing numbers of young people are using ketamine as Guardian analysis of government data shows the number of police seizures of the drug increased by 30% last year.

According to Home Office figures, while the overall number of drug seizures by police fell by 2% in 2017-18, officers carried out 653 confiscations of ketamine in 2017-18, up from 504 the year before.

This represents the third year-on-year increase after seizures of ketamine fell dramatically in 2013-14, around the time that supplies of the drug dried up following a crackdown on its production in India and it was reclassified as a class B substance in the UK.

Ketamine, which is often used as a tranquilliser in veterinary medicine, produces a trance-like state in users, which can range from a relaxed feeling to one of paralysis. It is on the World Health Organization’s list of essential medicines due to its pain-relieving properties. Negative effects of too much use include bladder damage and depression.

According to the latest government crime survey for England and Wales, the proportion of adults aged 16 to 59 who had used ketamine in the past year rose in 2017-18, from 0.4% to 0.8%, equating to 141,000 more people using the drug than in the previous year.

This was driven by an increase in the proportion of 16- to 24-year-olds using the drug, from 1.2% to 3.1%, the highest figure since records of ketamine use began in 2006-07.

In December 2013, the Home Office reclassified ketamine from a class C to a class B drug “in light of the evidence of chronic harms associated with ketamine use, including chronic bladder and other urinary tract damage”.

Rosanna O’Connor, the director of alcohol, drugs and tobacco at Public Health England, said: “PHE are concerned by recent signs that ketamine use is increasing, especially among younger drug users.

“Ketamine is addictive and is associated with a variety of serious health risks that not everyone who uses the drug may be aware of, such as ketamine bladder. We are advising clinicians who work with drug users to look out for urological symptoms which may be caused by their ketamine use.”

Robert Ralphs, a senior lecturer in criminology at Manchester Metropolitan University, said ketamine had become firmly established as the third most popular drug among students after ecstasy and cocaine, partly because it is cheaper – a gram of ketamine costs about £30.

“There’s been a huge change in attitudes to ketamine,” said Ralphs. “When I was going out in the 90s you had stories about how ecstasy pills had ketamine in them rather than MDMA [also known as ecstasy] and lots of people stopped taking pills because they were worried about it.”

One 23-year-old from London said he had first tried the drug in his teens and used to take it most weekends. “I grew up in the middle of nowhere, so there wasn’t really much else to do,” he said.

He now takes it every few months. “Whereas with other drugs it’s about getting wired and seeing how long we can stay up and talk nonsense, with ketamine you can just sit down in someone’s flat and watch TV,” he said.

“I have seen people getting addicted to it. It can start to become not a weekly thing or a monthly thing, but something people do every day after work or school. People think it’s a not a very addictive drug and so they do it in a very blase way and don’t think about the negative effects.”

A 30-year-old living in Manchester, who has taken ketamine occasionally for 13 years, said he had seen the quality of the ketamine supply in the UK fall. “About 10 years ago you never used to worry about it being good [...] but now you can be sold rubbish stuff that doesn’t do anything.”

He said he was not worried about the possible negative side-effects. “The small amounts I’ve done over the years don’t give me great worry,” he said. “I worry much more about how much alcohol I drink, because I do that five or six nights a week.”

Harry Sumnall, a professor in substance use at the Public Health Institute, Liverpool John Moores University, said ketamine became a popular club drug in the late 1990s to the early to mid-2000s, but that there was a backlash against it around 2010 when its side-effects, such as bladder damage, were publicised. Sumnall said that, unlike previous times, the rise in popularity of ketamine did not seem to be attached to a particular music scene.

Martin Raithelhuber, an expert on illicit synthetic drug at the United Nations Office on Drugs and Crime (UNODC), said most ketamine for recreational use was being produced in clandestine labs in Asian countries, particularly China. He said there was evidence that a recent Chinese government crackdown on ketamine production had pushed the trade into neighbouring countries.

Additional reporting by Brogan Maguire.