Older People Need Only Half the Dose of Sleeping Pills
Research into how drugs affect young people and older people differently has led some experts to the conclusion that older patients should have their doses of certain medications reduced. It has been found that some drugs, particularly sleeping pills, are more effective in older people, meaning that a smaller dose could help to prevent unwanted side effects.
Dr Ian Maidment, a pharmacist at the University of Aston, has pointed out that most drugs trials are done on healthy younger people. Considering their lack of other illnesses and the fact that they most often do not take other regular medication, the results gleaned from these trials may not always be directly applicable to older people. He says that aging reduces the liver’s ability to break down drugs and the kidney’s ability to excrete them effectively.
“Overall, drugs stay in the body for longer and are more likely to cause side effects and have a stronger effect,” he says.
“There’s increasing recognition that drugs don’t always work in the same way for every individual and that age can be an important factor, along with other factors such as genes, weight and whether someone can produce the right enzymes to break down a drug,” says Dr Chris Fox, consultant in psychogeriatric medicine at Norwich Medical School at the University of East Anglia.
A Study on the Effects of Aspirin in Older Women
Researchers at the University of Utrecht studied 30,000 women and found that low doses of aspirin begin to help prevent cancer and heart disease in women over the age of 65, when taken every other day. However, the same intake caused more negative side effects for younger women, such as gastro-intestinal bleeding.
“This new study had some unexpected results as in most cases drugs seem to work better in younger people,” says Dr Fox. “Older people often metabolise medicines more slowly, so the levels of the drug are too high and more likely to cause side effects.”
A number of drugs have been found to work differently in older people. Anticholinergic drugs have been associated with more negative side effects in older people, such as blurred vision and memory problems. Anticholinergic drugs include the likes of antihistamines, some antidepressants and diuretics. These drugs block the action of a chemical messenger in the brain called acetylcholine, which affects memory and co-ordination.
Why Older People Need Less Sleeping Pills
Meanwhile, some drugs which help with sleep problems have been found to be more effective in older people. Circadin, used to treat sleep disorders such as insomnia, is licensed only for those over the age of 55 because trials showed that it is ineffective in younger people. Similarly, sedatives such as zopiclone have proved significantly more successful in older people.
“As a rule of thumb, an older person needs around half the dose of a younger person to achieve the same effects,” says Dr Maidment. “But GPs, consultants and nurse prescribers may not consider age when they are prescribing sleeping pills and just give the standard dose. Having too high a dose can result in excessive drowsiness, so if this happens to you it’s worth going back to your GP to ask for the dose to be reduced. The same is true of all anti-psychotic drugs that are sometimes prescribed to patients with dementia, which should be used at much lower doses for older people, if at all, as they are more likely to get side effects.”
It has also been highlighted that the effect of a drug can be altered by the presence of other drugs in the system, and that this should be taken into account when new drugs are prescribed. Sultan Dajani, a community pharmacist and spokesman for the Royal Pharmaceutical Society, says that the average person over the age of 65 is on eight different medications, “but even three drugs can interact with each other and make side effects and complications more likely.”
If you are concerned about any drugs you have been prescribed, don’t hesitate to speak to your GP or your local pharmacist.