Fatal cocktail of common drugs puts elderly at risk, says study
Published 24/06/2011 | 05:00
Hundreds of thousands of older people are being put at increased risk of death or developing dementia by taking combinations of common medicines to treat routine illnesses, a major new study warned yesterday.
Well-known brands of hay- fever tablets, painkillers and sleeping pills pose a previously unknown threat to people's health when taken together, British scientists claim.
And because many are available over-the-counter at pharmacists -- as well as being prescribed by GPs, nurses and chemists -- patients are unknowingly putting themselves in harm's way, the research shows.
Yesterday the scientists called for doctors to recognise just how dangerous these combinations of drugs can be and to prescribe harmless alternatives instead while further research is carried out
Researchers from the University of East Anglia and the University of Kent identified 80 widely prescribed over-the-counter medications which, when used in combination, were found to increase health risks to patients. The drugs include common allergy treatments Piriton and Zantac, which, when taken alongside Seroxat, an anti-depressant, were found to more than treble an elderly patient's chance of dying within two years. Common bladder medications, heart drugs and asthma treatments were also among those which pose a risk.
The scientists claim the combination of treatments can also worsen dementia. In patients showing early signs of mental impairment high doses could "tip them over" into a more confused state, they say.
All the drugs work by blocking a key chemical in the nervous system called acetylcholine.
Previous research has shown they could have a harmful impact on the brain. But the new study is the first to examine the cumulative effect of the medications. "It is the cumulative burden which is very damaging," said Ian Maidment, one of the researchers and a pharmacist at the University of Kent. "It is not just the obvious medicines, it is things like heart drugs and antihistamines."
Researchers examined the medication records of more than 13,000 people aged over 65 over two decades and found that 48pc were using at least some of the drugs on the list.
They placed each drug into one of three groups based on how effectively they blocked acetylcholine.
The more effectively they block the chemical the more dangerous they are in high doses. The most dangerous included the antihistamines chlorphenamine (used in the brand Piriton) and promethazine (used in Phenergan), the anti-depressant paroxetine (used in Seroxat) and the incontinence drug oxybutynin (used in Ditropan).
The heartburn drug ranitidine (used in Zantac), beta blocker Atenolol, painkiller codeine and some eye drops were among the drugs in the mildest category. Low-risk drugs were graded one point, while high-risk drugs were worth three.
The study found that patients who took a combination of drugs which added up to four points or more had a 20pc chance of dying in the next two years, compared with just 7pc for over-65s who did not take anything.
The risk of dying increased by a further 25pc for each additional point accumulated, the study published in the 'Journal of the American Geriatrics Society' warned.
Rebecca Wood, chief executive of Alzheimer's Research UK, said: "The results underline the critical importance of calculated drug prescription. Further investigation needs to establish exactly how and why (these) drugs are increasing mortality, which might offer clues to safer drug design." (© Daily Telegraph, London)