At least £100m from the National Health Service budget and almost £2bn worldwide is being spent unnecessarily each year on drugs to treat indigestion, according to an editorial in this week's BMJ.
Proton pump inhibitors are one of the most frequently prescribed classes of drug in the world, write two gastroenterology doctors at King's College Hospital in London. They work by inhibiting the backflow of stomach acid that causes indigestion (dyspepsia).
In 2006, expenditure on these drugs was £425m in England and £7bn globally.
Effective and less expensive alternative drugs are available for many patients. Yet prescriptions for proton pump inhibitors have superseded those for all other acid inhibiting agents and now account for over 90% of the NHS drug budget for treating dyspepsia.
Because of their higher cost, prescribing guidelines have been drawn up in several countries and in the UK recommendations for using these drugs - particularly in the long term - are relatively selective.
So what is the evidence that guidelines are not followed?
In a study of hospitalised patients taking proton pump inhibitors in Australia, Ireland, and the UK, 63%, 33% and 67% of patients did not meet their country's criteria for taking the drug, while a US study of hospital in-patients found that most were taking these drugs unnecessarily at time of discharge.
In primary care, a Swedish study of patients who had been taking proton pump inhibitors for four years showed 27% were able to discontinue the drug altogether, while an audit of patients admitted as a medical emergency to a hospital in Wales found that a quarter were taking proton pump inhibitors, but in only half of the patients was the drug deemed appropriate.
After disseminating the NICE guidelines to local doctors, a repeat audit was performed six months later, which found that the same proportion of patients were taking a proton pump inhibitor and again, that only half of these had a recommended indication.
Proton pump inhibitors have been a tremendous therapeutic advance and have transformed the lives of patients with previously intractable symptoms, say the authors. But the drugs are clearly being overused.
There is evidence that taking proton pump inhibitors trebles the risk of Clostridium difficile infection.
They point out that side effects, although quite rare, should not be overlooked, but the adverse effect of overprescription on drug budgets around the world is the real problem. Quite how to motivate doctors to follow guidelines is a matter of considerable importance, they conclude.