It has a street name of 'bubble', but mephedrone, which can be bought over the internet, is causing serious health problems

Growing numbers of teenagers and young people are receiving emergency medical treatment after being harmed by a legal drug that has the same effects as ecstasy and cocaine.

Users of mephedrone are ending up with nose bleeds and burns, paranoia, heart palpitations, insomnia and memory problems. Some have had such a strong reaction to it that their hearts have stopped and they have had to be resuscitated.

The drug – also known as "drone", "bubble" or "meow meow" – is causing concern to NHS staff, drug workers and the police, who are powerless to control it because it is legal. It comes in powder, tablet, crystal or liquid form and is ­marketed as plant food or bath salts, often via the internet.

Mephedrone sparked concern in November when it was linked to the death of 14-year-old schoolgirl Gabrielle Price in Brighton, although police later said she died from bronchopneumonia. However, Sweden is one of a number of European countries concerned about the safety of this and several "legal highs" .

Its popularity is in part because it is cheaper and more effective than ecstasy and cocaine, easy to obtain and involves no threat of prosecution, according to the forthcoming issue of Druglink magazine. Dealers in Britain are spending £2,500 to ship one kilogram from China, then sell it at £10 a gram for a profit of £7,500, it reports.

In York, the city's main Hospital is experiencing a rise in the number of A&E admissions linked to the drug. Most were teenagers or those in their early 20s who had been to a nightclub. Their symptoms included anxiety, a racing heart-rate, convulsions, paranoia and palpitations. A local police officer said some users of the drug had needed to be resuscitated after their hearts had stopped.

Aggression is another of the drug's potential side-effects. "We have had officers assaulted by people high on it and two people have collapsed in the street. This drug is becoming more prevalent", said Inspector Kevin Tuck of Durham Police. Another local man took 36 hours to come down from his mephedrone high and was then still seriously paranoid afterwards, Tuck added.

In West Yorkshire, police have warned that mephedrone is proving popular among 14- to 25-year-olds and that it could lead to mental or physical damage. Last week a 17-year-old sixth-former collapsed at school in Pocklington in the East Riding of Yorkshire after taking a dose and was taken to hospital.

In Dundee, five users had non-fatal overdoses during one weekend alone in November. Dundee drugs worker Gareth Balmer said the city was "awash" with mephedrone, which locals call "bubbles". It first appeared there in early 2009. "It may have a cute name, but it's very dangerous," said Balmer.

Martin Barnes, the chief executive of Drugscope, said the rapidly rising number of online vendors of the drug was playing a key role in its booming popularity. "The ease with which people can buy mephedrone and the speed at which it appears to have grown is clearly a concern," he said.

"Mephedrone has been linked to a number of hospital admissions in recent months and it appears users can become dependent on it. Treatment services are starting to report people coming forward with physical and mental health ­problems linked to mephedrone use. It's vital that drug workers have guidance on how to support them."

The Advisory Council on the Misuse of Drugs (ACMD), the government's advisers on illicit substances, wrote to the home secretary, Alan Johnson, last month warning that while the potential harms of "legal highs" were still unknown, they "could have serious public health implications".

Professor Les Iversen, the ACMD's interim chairman, said it was taking urgent action about mephedrone because of members' concern about its spread. It plans to hold evidence sessions to try to find out more about the scale of its use and the harms associated with it.

The ACMD is expected to advise Johnson to make mephedrone illegal under the Misuse of Drugs Act. But dealers have told Druglink that even if that happens, other substances which are chemically similar but different enough to remain legal would emerge. The ACMD has told Johnson that five other synthetic psychoactive cathinone derivatives similar to mephedrone are already widely available.