The Swinging Sixties generation is the reason for a rise in the number of pensioners being hospitalised for recreational drug use, according to experts.

In the past two years, 27 people aged 60 and over have been taken to Queen’s Hospital in Romford for opiates, cocaine or cannabis poisoning.

Among them were two opiate users in their 90s and another patient, aged between 85 and 89, who was admitted for cocaine use.

The increase on the 22 admissions in 2011/2012 and the 16 in 2009/2010 was revealed through a Freedom of Information Act request to Barking, Havering and Redbridge University Hospitals (BHRUT) NHS Trust.

The spike is in line with a rise at King George Hospital, Goodmayes, which had 12 admissions in the past two years, and national statistics, which show admissions for people aged 65 and over have grown from 334 to 912 in a decade.

David Raynes, of the National Drug Prevention Alliance, said: “It isn’t surprising. We are dealing with the ’60s generation, some of whom never got free of drugs. I suspect it’s people who have dabbled for most of their life.

“If people use them for long enough they will get problems.”

More than half of the patients taken to Queen’s were over 75, and would have been in their 20s during the 1960s when drug taking was first glamourised by rock stars.

Of the 65 admissions over the past six years, 83pc – 54 – have been for poisoning by opiates, which cause more drug deaths than any other substance.

After falling out of fashion among users, deaths from heroin fell from 981 in 2001 to 579 in 2012. But in 2013, the figure increased to 765, up 32pc.

Fears were raised in January about a possible heroin epidemic after research showed prescriptions of oxycodone reached the one million mark in the UK last year, a 39pc increase on 2010.

Dubbed “hillbilly heroin,” the drug sparked concern in the US, where it is known as oxycontin, when experts said users were getting addicted and switching to heroin because it was cheaper and easier to buy.

Initially prescribed for late stage cancer, oxycodone is now given to treat a wider range of conditions. Actor Philip Seymour Hoffman died last year from an overdose after allegedly relapsing into heroin and oxycodone use.

Rupert Oldham-Reid, senior researcher at the Centre for Social Justice, who published the statistics, said questions needed to be asked about the drug’s “dramatic rise”.

“It is right we ask why this is happening and what the effects may be,” he said. “Oxycodone plays an important medical role, but we have to make sure we don’t over-prescribe and risk facing the problems they now see in America.”

Leading drug charity Drugscope said elderly heroin use in the UK had nothing to do with oxycodone.