Medications and the Elderly - Why are They at Risk
Older adults are particularly vulnerable to the risks associated with drug therapy. In other words, the elderly are more likely to become intolerant or develop side effects from their medication. There are a number of reasons why this is the case (also see 'The elderly - when drug therapy gets old' below).
The most obvious reason is related to the fact that as we age we are more likely to develop chronic conditions or disease states. These typically require long-term drug treatment, quite often a multiple of drug therapies for each medical condition.
As a result, the number of drugs taken often accumulate with age. And as the number of drugs increase so does the risk of developing adverse events.
Polypharmacy refers to the use of multiple medications (5 or more) and involves the use of inappropriate or more medications than clinically needed. Polypharmacy is particularly worrisome among older adults and is associated with increased risk of adverse drug events.
A large study of almost 3000 older adults demonstrated that 14% developed an adverse drug event (ADE) over the course of a 1-year follow-up. The risk of having an ADE doubled when taking five to six medications and tripled with seven or more therapies.(2)
We are all aware that as we age, our body changes. What is less obvious are the changes that occur internally to some of our organs. Like anything we ingest, it must be processed. Food is processed via our gastrointestinal system. Drugs are processed or metabolized and eliminated mainly through two organ systems, that is, our kidneys and liver.
And, this elimination process is where the kidneys become involved. They essentially are the filtration units that draw unwanted substances from our blood, such as liver-metabolized drugs.
Unfortunately these organs begin to fail as we age and become less efficicient. The liver is less capable of metabolizing and the kidneys less able to eliminate the drugs that are ingested.
Ultimately, these age-related changes can result in the following:
Fortunately a medication review in the elderly can help minimize all of these unwanted issues.
The elderly – 'when drug therapy gets old'
A better understanding of what makes them different from younger adults (4)
The elderly really are special in many ways – a wealth of experience, great story telling, a great source of knowledge etc. When it comes to medication they are really special. They are not like younger adults. Their bodies have matured and continue to do so. This has significant implications with regards to how they should be medicated. And, an additional effect on how they are likely to respond to therapy.
2. The liver is also becoming less efficient.
1. Kwan D, Farrell B. Pharmacy Practice 2013; Apr/May 2014: 20-25
2. Field TS, et al. Arch Int Med 2001;161 (13): 1629-1634
3. Hilmer SN. et al. Ther Clin Risk Manag. 2005; 1(2): 151-56
4. Turnheim K. Experimental Gerontology 38 (2003) 843–853
3. Changes in body mass
There are no simple rules when it comes to initiating a drug therapy in the elderly. Drug administration in the elderly is often complicated by a number of medical conditions, a greater number of medications and physiologic changes that occur with age. Having said this, there is a tendency in the elderly to be at much higher risk for drug accumulation and toxicity. We must remain vigilant and look for signs that might be indicative of adverse drug events. One of our best and often overlooked tools to help optimize a drug regimen and prevent possible unwanted reactions remains a periodic medication review.