The number of patients admitted to hospital for overdosing on painkillers has doubled in a decade, NHS figures show.
Doctors say it is a 'very worrying' consequence of the pills being prescribed too readily.
There were 10,999 admissions in 2016/17 for poisoning by opioid painkillers and other narcotics, which include codeine, morphine and fentanyl.
This is up from 5,085 in 2006/7, although slightly down on 2015/16, when there were 11,660 admissions, the data from NHS Digital shows.
Dr Jane Quinlan, a consultant in anaesthesia and pain management at Oxford University Hospitals, said the ten-year rise was 'very worrying'.
A shocking 11.5 million American adults abused prescription opioids in 2015, a survey shows
But she pointed out that it was not clear whether people had overdosed by accident or after becoming addicted to the drugs.
'These figures confirm fears that the increase in opioid prescribing and availability has broader consequences,' she said.
'I have also seen patients taking more opioids than they should because they were desperate to treat their pain, even though we know they are unlikely to be effective; some who have taken them as a deliberate suicide attempt – sometimes because of the pain – and some who have become acutely hypersensitive to their normal opioid doses as a result of a chest infection or other infection.'
A spokesman for NHS Digital pointed out that the figures were not directly comparable as from 2012 the data changed slightly to include poisoning from the drug tramadol.
A rise in prescriptions?
THE SAME PROBLEM EXISTS IN THE US
It's not just a problem in England. A shocking 11.5 million American adults abused prescription opioids in 2015, a survey showed in July.
Federal data analyzed by the Boston Medical Center show the prevalence of excessive prescribing of painkillers, leaving unused pills available for recreational use.
In 2015, 91.8 million adults in the United States used prescription opioids, 11.5 million misused those drugs, and 1.9 million reported addiction.
Prescription opioids, such as hydrocodone and morphine, are behind the deadliest drug overdose epidemic in US history.
More than 52,000 Americans died of overdoses in 2015 - an all-time record - and experts believe the numbers have continued to rise.
Roger Knaggs, a pain expert at the Royal Pharmaceutical Society, said the rise in patients admitted with poisoning could be mainly attributed to the rise in prescriptions. It could also be down to more people buying the drugs online, he added.
'In order to improve discharge from hospital after surgery more people are being discharged with supplies of opioids and these may be being continued in the community.
'Equally, there is a misheld perception that as 'strong' analgesics they are effective for all types of pain – however, that is not the case for long-term non-cancer pain.'
Experts blame it on tramadol
Harry Shapiro, the director of DrugWise, an online drug information service, said: 'The key drug here is tramadol. There is a jump in admissions once they included it in the statistics.
'The drug is one of the most popular opiate painkillers to be prescribed for pain and numbers of prescriptions have risen dramatically in recent years.
'Nobody wants to deprive people of a valuable pain medication, but there needs to be better risk assessment and monitoring at a primary care level – and more dedicated services for people who actually have a problem with opiate painkillers, and clearly more public awareness of the risks of overdose.'