The sale of codeine-based painkillers over the counter is worth more than £500million to the drug industry. But they carry a risk of addiction, meaning guidelines for their sale have had to be tightened. Fiona Foster reveals just how easy it is to buy large quantities of these drugs and meets people who lost everything when codeine addiction took hold. More than 900,000 people across the UK could be misusing over-the-counter painkillers containing codeine, a drug derived from morphine, the Tonight programme has found. There are no firm figures about the scale of this problem yet so Tonight commissioned a survey. We asked 2000 people whether they took these drugs, what they used them for and if they took them in accordance with the guidance of 6-8 tablets a day for a maximum of three days.