The combined side-effects of commonly-used drugs can increase the risk of death and brain impairment in people over 65, according to a study of more than 13,000 people. Researchers have urged people who are taking a combination of medicines to review their intake with their doctors in light of the findings.
The study was part of the Medical Research Council’s Cognitive Function and Ageing Studies project and looked at a specific class of commonly used drugs being taken by people over 65 over a two-year period.
“The sort of drugs we’re looking at are used in allergies, depression, cardiac disease, bladder disease, pain relief and sometimes in anti-coagulation, very common drugs, some prescribed, some over the counter,” said Chris Fox, clinical senior lecturer at Norwich Medical School who led the research.
The list includes over-the-counter medicines such as Piriton and Nytol, and the anti-depressant paroxetine, used in Seroxat.
Fox rated the activity of different drugs on a messenger chemical in the brain on a three-point scale, with 0 for no effect and 3 for a severe effect. The results, published in the Journal of the American Geriatrics Society, showed that around 20% of those people who took a regimen of drugs that scored more than 4 on the scale had died in the two years of the study, compared with only 7% of those not taking any medication in the drug class. “For every extra point scored, the odds of dying increased by 26%,” said Fox. “We found it was a cumulative risk – not just the severity of the blockade but the number of drugs as well.”
Ian Maidment, a pharmacist at Kent and Medway NHS & Social Care Partnership Trust, said that many doctors, nurses and pharmacists may not be aware that these medicines have these problems and cited overuse of drugs as one of the factors adding to the cumulative burden on people over 65. “Often you see anti-histamines, which have a high burden, for hay fever and they are continued in the depths of winter when there is snow on the ground. The problem is that someone with dementia can’t say, ‘I don’t need anti-histamine,’ so it’s continued when it’s not needed.”
Participants in the study who were taking drugs with a combined score of more than 5 also showed cognitive decline – they scored more than 4% lower in cognitive function tests compared with those who were taking no anti cholinergic drugs.
“The message here is for doctors to regularly review the medication of your older patients,” said Susanne Sorensen, head of research at the Alzheimer’s Society. “The message to patients is to ask, when you’re given medication, the pharmacist if what you’re buying at the counter has any side-effects and may be bad in combination with the other drugs you take..”
Professor David Nutt, president of the British Neuroscience Association and vice-president of the European Brain Council, said that the negative effects of this class of drugs on brain and cardiac function had been known for decades and the latest study reinforced the dangers.
Dr Tim Chico, an honorary consultant cardiologist at the University of Sheffield, added that all drugs had possible side effects, but the new results should not lead anyone to stop current medications without discussing this with their doctor first. “Before starting any drug, it is important for the doctor and patient to discuss the possible benefits of the treatment, compared with the potential downsides, so that the patient can make an informed decision. As a cardiologist, many of the drugs I use (such as beta-blockers) have been definitely proven to make people with heart disease live longer, so it’s important to balance these proven benefits against the risk of side effects.”
By Guardian June 2011