Once helpful drugs can turn risky
5 May 2012
IN her rounds among nursing home residents in regional Western Australia, GP Kathleen Potter regularly encounters patients taking 15 to 20 different medications.
Upon reviewing the plethora of pills, she often discovers that more than half of the drugs being faithfully consumed are probably not needed. And worse, they may be doing more harm than good.
Seeing this scenario again and again, Potter noted that while she was bombarded with information about how and when to start patients on new drugs, there was almost nothing available on when it might be appropriate to withdraw them.
"It made me think, is this really in these people's interest? Are they really benefiting?" says Potter, a research fellow at the University of Western Australia, who has since teamed up with UWA associate professor Christopher Beer to study how drugs can be safely "de-prescribed."
So far 28 patients in WA aged care facilities have enrolled in their trial, which will measure whether quality of life and cognitive and physical function improve as drugs are withdrawn.
"As people get older, their livers and kidneys don't work as well, so the way that they process drugs changes, and they're more at risk of toxic effects without necessarily getting the same level of therapeutic benefit," Potter says.
Compared with their younger counterparts, older patients are more likely to experience adverse events. These can range from irritating side effects such as dry mouth, nausea and constipation to more serious and potentially fatal issues, such as increased risk of fractures and falls, and uncontrolled bleeding.
Likewise, the more medicines a patient is on, the higher the risk of confusion and memory problems, signs of dementia, falls, hospitalisation, entering into aged care and dying. Patients taking more medications are also more likely to become frail. And last month South Australian researchers published in the International Journal for Quality in Health Care the results of a five-year study of more than 100,000 veterans that attributed 20 per cent of more than 1.6 million hospital admissions to potentially preventable mismanagement of medications.
Professor David Le Couteur of the University of Sydney's Centre for Education and Research on Ageing, who is also president of the Australasian Society for Clinical and Experimental Pharmacologists and Toxicologists, is one of the most prolific researchers on the subject. He says there is a disconnect between the evidence base and clinical practice. Randomised controlled trials rarely include people over 65, and most clinical guidelines for older people are extrapolated from younger populations. Yet older people use medicines extensively, and polypharmacy - the practice of taking many different drugs at once - may even be increasing.
"A typical person in their 80s will have five or more different illnesses and they're chronic, and what we do is tend to treat each disease individually so the older person ends up being on five to 10 different medicines," he says.
"But we have very little evidence that treating multiple diseases with multiple drugs is useful. It's being increasingly recognised that the guidelines are perhaps driven by things that are more marketing-related than patient-related, so they're being used to encourage particular drugs and they don't take into account co-morbidities or end-of-life issues."
Experts say various factors can lead to people taking medications that render them few, if any, benefits. Sometimes the meds are effective at first, but the patient becomes tolerant, as is often the case with sleeping pills. Or people go to more than one pharmacist, become confused when they receive a generic drug instead of the brand-name version they are accustomed to, and end up taking both. Many neglect to mention over-the-counter and complementary and alternative therapies to their doctor, not realising they can interact or cause side-effects without any benefits.
In other cases, patients continue taking drugs that were once benefiting them, even though their situation may have changed. For example, someone in their 50s or 60s might be prescribed nitrates for angina, which is usually triggered by exertion. This makes sense when they are likely to, say, climb stairs. But if the patient later becomes sedentary or confined to a wheelchair, the risks are likely to outweigh the benefits.
Meanwhile, as people reach their 80s or 90s, the potential side-effects of drugs that lower cholesterol or blood pressure, or thin blood, may be of greater concern than the events they aim to avoid.
"If you're in your 90s and you're on a blood pressure medication, you're much more at risk of falling," Potter says. "You're more likely to die from falling over and breaking your hip and getting pneumonia than you are from having a heart attack or stroke."
The Home Medicines Review is one government initiative designed to reduce adverse events in patients living at home. Once a patient is referred by their GP, an accredited pharmacist will go through everything the patient is taking, prescribed or otherwise, and send a report to the doctor. There is evidence these reviews do reduce adverse events. Recent research shows patients taking the blood thinner warfarin or on medications for heart failure are less likely to be admitted to hospital if they have received an HMR.
However, access to the program remains low.
"The patients who are fortunate enough to have a review by someone who knows what they are doing appreciate it," says Ben Basger, a community and private hospital pharmacist and Sydney University researcher who regularly performs HMRs.
"But you have to bear in mind that less than one in 10 doctors believe in them or fill out the referral forms, so that's a limiting factor, and the majority of patients who are discharged from hospital don't get them.
"It's a valuable service but it needs to be extended."
Perhaps the biggest barrier, however, is convincing people that discontinuing medications they have been on for years is in their own best interest and that such action doesn't mean the doctor has given up.
Potter and Beer initially hoped for 250 participants for their pilot study, but now say 100 to 150 would be more realistic, as only about 10 per cent of non-dementia patients they have approached have agreed to participate.
"A lot of people are quite nervous about it," Potter says. "We need to help patients and their carers understand that stopping medications can actually help them feel better."