A man and woman hooked on headache tablets kept video diaries of their struggle to overcome their addiction for BBC One's Real Story.
Janet Richardson found it agonising to go without her painkillers
Derek Hartsthorne and Janet Richardson have never taken an illegal drug in their lives, yet they feel a certain shame that they have become addicted to over the counter painkillers.
The 44-year-old factory worker and 54-year-old beautician are among the thousands of people in Britain who are reliant on the drugs.
Like many other everyday users, Derek and Janet did not initially realise the risks of taking the medication over prolonged periods or in exceeding the recommended dose.
When Derek's prescription to ease his stomach ulcers ran out four years ago, he began buying huge quantities of a weaker version of the medicine. Over the past six months, the father of five has averaged 16 to 20 painkillers a day.
Janet, a teetotaller and practising Mormon, spent the last decade developing a ten-a-day habit to the non-prescription painkiller Solpadeine to treat her increasingly frequent headaches.
The painkillers used by the pair are available only on prescription in the US but can be purchased for a few pounds a packet from any UK pharmacy. They contain the narcotic opiate, codeine.
A percentage of the codeine in every tablet converts into morphine in the brain which gives a feeling of well-being.
Derek Hartsthorne was determined to kick his habit for his family
Dr Massimo Riccio, a leading addiction specialist at the Priory Clinic in Roehampton, says those trying to kick a serious codeine habit may suffer symptoms not dissimilar to someone weaning themselves off a class A drug.
"You may experience increased perspiration, cold sweats, stomach cramps, a runny nose, and generally feel unwell. Psychologically you may feel more irritable and may not sleep well."
Flu-like aches and heightened anxiety were clearly problems for Derek and Janet when they resolved to give up painkillers.
They both hoped keeping a video diary of their withdrawal for the Real Story programme would give them a further incentive to quit.
Derek followed a five-week programme drawn up for him by the drugs charity Turning Point, while Janet decided to go "cold turkey" and recorded her progress in her first 48 hours without any pill popping.
Although Janet's daily dose was not as high as Derek's, she had been diagnosed with medication overuse headache by a specialist at York University.
After years of being numbed by pills, the pain receptors in her brain had become sensitised. This had led to more headaches and more painkiller use, the one driving the other.
Dr Tim Steiner, a consultant physiologist at Charing Cross Hospital, told Real Story medication overuse headache was a big public health issue.
"It's a massive concern, crying out for the people who have the resources to conduct the studies to understand the scale and scope of the problem and find ways of dealing with it."
With 50 brands to choose from, has the explosion in the painkiller market made us loose sight of the fact that our pain threshold acts as a signal to stop us from injuring ourselves?
"Everything is focused on finding a quick fix," said Dr Ricchio. "We find a pill for every ill but sometimes there is a reason for the pain and we have to work through it."
A spokesperson for GlaxoSmithKline, makers of Solpadeine, does not believe there is evidence that abuse of over the counter medicines exists.
"I can't believe at 8 mgs per tablet, people can take enough to become addicted in a medical sense."
Janet has resigned herself to her addiction to Solpadeine
But David Grieve who runs Overcount, a self-help charity supporting more than 13, 500 addicts, estimates there are actually more than 30, 000 Britons with the problem.
A survey of his clients revealed that 70% of sufferers were women, with the largest group being in the 25 to 35 age range. Of those who admitted their addiction; 52% were housewives; 27% one-parent mothers and a further 21% were professionals who often took up to 75 tablets a day over a four to five year period.
The Propriety Association of Great Britain, the trade body representing manufacturers of non-prescription drugs, told Real Story it was in the process of setting up a helpline.
The Real Story case studies accepted they were responsible for not complying with the manufacturers' instructions and warnings by exceeding the dose stated on the painkiller packets.
But juggling a busy job with headaches proved too much for Janet and half way through her second tablet-free day she filmed her last entry in the video diary from her home in Woodlesford, Leeds.
"I've taken some Solpadeine. I don't know whether I will feel a failure but I'm resigning myself to the fact that maybe I'm going to have to carry on to take a small dosage."
For Derek, his staggered approach to withdrawal meant he finally overcame his demons.
"I just hope this video diary will help somebody else stop," he told the camera, set up in his lounge in Wakefield.
"You do realise there is more to life than tablets. I have no intention of taking them again."
Real Story: BBC One, Monday 9 August 2004, 1930 BST and live on the Real Story website.
If you are thinking of cutting down the number of painkillers you take, experts say you must seek advice from a doctor.