The aging population of the United States creates pharmaceutical challenges for the practicing emergency physician. Polypharmacy, drug-drug and drug-disease interactions, and other pharmaceutical complications from the pathophysiologic changes associated with aging need to be recognized in order to optimize outcomes in the elderly. Effective strategies that improve patients outcomes include a better understanding of the physiologic and pharmacologic changes that occur with aging, integrated use of clinical emergency department pharmacists, and choosing nonpharmacologic treatment options when possible.
Key points
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A higher proportion of emergency department patients in the future will be elderly.
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Elderly patients are often prescribed multiple medications by multiple providers.
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Physiological changes with age affect drug metabolism, effect, and elimination.
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Drug interactions are more common in elderly patients.
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Involving clinical pharmacists can avoid drug interactions and polypharmacy and improve resource utilization.
Introduction
According to the US Census Bureau, from 2012 to 2050 the country will undergo significant aging, wherein the proportion of persons 65 years and older (defined as “older population”) will increase at a more rapid pace when compared with persons younger than 65 years. As technology and medical knowledge continue to advance, a growing number of older patients will survive previously fatal disease processes, such as cancer, organ transplantation, and human immunodeficiency virus. With this increasing proportion of elderly patients, pharmacologic issues specific to this patient population will become more pronounced because the need for long-term medication use naturally increases with age.
Although medication reconciliation in the emergency department (ED) has been an important national priority, understanding the long-term implications of polypharmacy has only recently received close attention. Recent data confirm that most front-line caregivers have seen increased rates of prescription drug use in all ages in the United States (from 51% in 1999–2000 to 59% in 2011–2012). More importantly, during that same time period, the rate of polypharmacy in the United States doubled. Simply being on a few medications when younger significantly increases the risk for polypharmacy as one gets older. The problem of polypharmacy is not limited to the United States, but instead is a worldwide phenomenon. A Scottish study demonstrated patients prescribed 10 or more medications increased from 4.9% in 1995 to 17.2% in 2010. Polypharmacy in the elderly is particularly important to recognize in the ED, because with increased age comes increased frailty, defined here as decreased function of multiple organs, loss of physiologic reserve, and increased risk of disease and death.
The definition of “polypharmacy” is controversial. It is important to note 2 themes, which emerge consistently in most published works on polypharmacy: either too many medications are prescribed or medications that are not clinically indicated are administered. Definitions of polypharmacy in published studies have ranged from 2 to 10 prescribed medications. Today, the most commonly accepted definition for polypharmacy by scholars in current use of 5 or more prescribed, because that number of medications is associated with poor mental and physical health.
Introduction
According to the US Census Bureau, from 2012 to 2050 the country will undergo significant aging, wherein the proportion of persons 65 years and older (defined as “older population”) will increase at a more rapid pace when compared with persons younger than 65 years. As technology and medical knowledge continue to advance, a growing number of older patients will survive previously fatal disease processes, such as cancer, organ transplantation, and human immunodeficiency virus. With this increasing proportion of elderly patients, pharmacologic issues specific to this patient population will become more pronounced because the need for long-term medication use naturally increases with age.
Although medication reconciliation in the emergency department (ED) has been an important national priority, understanding the long-term implications of polypharmacy has only recently received close attention. Recent data confirm that most front-line caregivers have seen increased rates of prescription drug use in all ages in the United States (from 51% in 1999–2000 to 59% in 2011–2012). More importantly, during that same time period, the rate of polypharmacy in the United States doubled. Simply being on a few medications when younger significantly increases the risk for polypharmacy as one gets older. The problem of polypharmacy is not limited to the United States, but instead is a worldwide phenomenon. A Scottish study demonstrated patients prescribed 10 or more medications increased from 4.9% in 1995 to 17.2% in 2010. Polypharmacy in the elderly is particularly important to recognize in the ED, because with increased age comes increased frailty, defined here as decreased function of multiple organs, loss of physiologic reserve, and increased risk of disease and death.
The definition of “polypharmacy” is controversial. It is important to note 2 themes, which emerge consistently in most published works on polypharmacy: either too many medications are prescribed or medications that are not clinically indicated are administered. Definitions of polypharmacy in published studies have ranged from 2 to 10 prescribed medications. Today, the most commonly accepted definition for polypharmacy by scholars in current use of 5 or more prescribed, because that number of medications is associated with poor mental and physical health.
Patient evaluation overview
Complications from medications should always be considered in the emergency physician’s (EP) differential diagnosis. Medication overuse and polypharmacy are only recently being recognized as common reasons for ED evaluation, and the number of cases will continue to increase as the population gets older and more patients are prescribed even more medications. Acute delirium from pharmaceuticals is underrecognized in the elderly, but should always be considered near the top of the EP’s differential. Elderly patients undergoing ED evaluation for altered mental status or delirium could result from using too many medications prescribed by too many providers, in cases when a patient unintentionally uses leftover medications that were discontinued but not discarded appropriately, in cases when they have visual impairment and take the wrong medications, in cases where they use another household member’s medications in place of their own, or in cases when they use their pets’ medications in addition to their own.
Evaluation of medications should happen at multiple stages during the ED visit, from the time of initial triage until final disposition to home or to the inpatient unit. It should include currently prescribed medications, previously prescribed medications, access to other household member or pet medications, and use of over-the-counter and herbal products. Despite progress in medical reconciliation with the introduction of electronic health records (EHRs), problems specific to this system include incomplete lists of medications when a patient uses multiple health facilities, historical medications not being verified, but remaining in the record, and lack of universal participation in medical record sharing, such as Care Everywhere. Use of an ED pharmacist can assist with rapid assessment of drug-drug interactions, adverse drug reactions, and other pharmaceutical-related complications. In fact, American College of Emergency Physicians recognizes the importance of ED pharmacists in a 2015 position statement: “The emergency medicine pharmacist should serve as a well-integrated member of the ED multidisciplinary team who actively participates in patient care decisions, including resuscitations, transitions of care, and medication reconciliation to optimize pharmacotherapy for ED patients.”
Several tools have been developed to prevent polypharmacy or inappropriate medication use in elderly patients; although not ED-friendly, it is important for the EP to be familiar with them. The Beers Criteria, developed by geriatricians and updated in 2015, are the most widely used tool for evaluating appropriate medication use in the elderly. The utility of the Beers Criteria is easily illustrated by comparing the difference between nursing home residents cared for by family medicine physicians and those cared for by geriatricians. Those cared for by family medicine physicians had 13.15 greater odds of being prescribed 9 or more medications and 6.25 greater odds of being prescribed one or more potentially inappropriate medications when compared with those cared for by geriatricians. This difference is especially notable, because patients cared for by geriatricians were found to be more complex with more comorbid diseases.
Beers Criteria include identifying medications in the following categories:
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Potentially inappropriate medication use in older adults
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Potentially inappropriate medication use in older adults due to drug-disease or drug-syndrome interactions that may exacerbate the disease or syndrome
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Potentially inappropriate medications to be used with caution in older adults
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Potentially clinically important non-anti-infective drug-drug interactions that should be avoided in older adults
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Non-anti-infective medications that should be avoided or have their dosage reduced with varying levels of kidney function in older adults
Beers Criteria identify patients at higher risk for admission to the hospital from medication complications.
The Norwegian General Practice (NORGEP) Criteria are another tool for optimizing prescriptions in the elderly. The NORGEP criteria include 2 tables of 21 single medications and 15 drug combinations considered by an expert panel to be potentially pharmacologically inappropriate for patients aged 70 years or older.
Both the Beers and the NORGEP Criteria are extensive, and although partially subjective, are grounded in common sense and include references for their decisions in their respective populations. Although the Beers Criteria focus mostly on potentially inappropriate individual medications, the NORGEP criteria also identify potentially dangerous combinations of drugs. They are the most commonly used tools by specialists outside of the ED.
Tools more adaptable to the ED environment include checklist or judgment-based tools. The Screening Tool of Older Person’s Prescriptions and Screening Tool to Alert doctors to Right Treatment are examples of checklist tools created to identify medications that should be avoided and “irrational prescribing omissions.” An example of a judgment-based tool is the Medication Appropriateness Index. These tools were developed by literature review and expert opinion but have not been externally validated.
Another tool to assess inappropriate medication use is the Anticholinergic Risk Scale. The elderly are especially sensitive to anticholinergics because of decreased function of multiple organs and loss of physiologic reserve. This tool is well recognized by clinical pharmacists and is useful in the ED setting where anticholinergics such as diphenhydramine are commonly used.
Another potentially useful tool for identifying at-risk patients greater than 80 years old is the 80+ score. Using this internally validated tool, patients at high risk for either death or rehospitalization within 1 year are those with current or history of malignancy, current pulmonary disease, impaired renal function, residing in nursing home, or current prescription for opioid or proton pump inhibitor (PPI).
Based on these definitions, criteria, and risk factors for pharmaceutical complications in the elderly, the EP should always perform the steps in Box 1 when caring for an elderly patient.
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Confirm age, sex
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Obtain complete medical history
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Obtain social history
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Confirm correct, up-to-date medication list
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Compare medications with those listed in a tool (of your choice) for potentially inappropriate medication
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Review list for historical or unnecessary medications
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Review list of other accessible pharmaceuticals in the household
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Consult with the primary medical provider and pharmacist for appropriate medication reconciliation at time of disposition
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Check baseline laboratory test results before starting new medications
Performing each of these steps takes time, especially in geriatric patients; thus, assistance from clinical pharmacists and other midlevel providers is important to optimize the outcome in these patients.
Pharmacologic treatment options
Pathophysiology
Cardiovascular system
Elderly people commonly have cardiovascular disease and require medications for this organ system. They also have decreased cardiac reserve, increased blood pressure partly due to decreased compliance of vasculature, loss of overall myocardial contractility, decreased vagal tone, and left ventricular hypertrophy. All of these factors are exacerbated by decreased sensitivity to catecholamines, causing elderly patients to be even more sensitive to cardiac medications.
Respiratory system
Aging is associated with loss of lung elasticity, decreased functional volume (despite maintained total lung capacity), and decreased vital capacity, all leading to decreased ability to eliminate carbon dioxide. Furthermore, forced exhaled volume decreases, increasing work of breathing.
Gastrointestinal system
In addition to decreased blood flow and liver function that changes with age, as countless medications are metabolized by the liver, this is an important consideration in medication administration and reconciliation. Decreased liver mass and decreased hepatic and biliary uptake and transport also contribute to deranged drug metabolism.
Urinary system
Kidneys are the primary means for elimination of medications. With age, renal mass decreases and glomerular filtration rate decreases for several reasons even in healthy elderly patients. Some of these reasons include decreased blood flow, decreased vascular compliance, and decreased muscle mass. Decreased muscle mass complicates evaluation of kidney function, because serum creatinine may not be as reliable a measure of kidney dysfunction, because it reflects muscle mass, which is frequently decreased in elderly people.
Endocrine system
Elderly patients experience decreased insulin secretion and insulin sensitivity, leading to decreased glucose tolerance; also complicating diabetes management in this population is deranged glucose counterregulation.
Nervous system
Like total body mass and liver mass, brain weight decreases by 20% with age, with a comparable loss of neurons. Although the synapse itself is not thought to change, elderly patients are more sensitive to analgesic and sedative/hypnotic medications, requiring dose reductions even before metabolism is considered. Possible explanations are alterations in calcium homeostasis or even structural changes in receptors, such as γ-aminobutyric acid A and N -methyl- d -aspartate receptors ( Box 2 ).
Cardiovascular
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Decreased cardiac reserve
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Decreased cardiac contractility
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Decreased sensitivity to catecholamines
Respiratory
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Decreased elasticity
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Decreased functional volume and vital capacity
Gastrointestinal
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Decreased hepatic mass
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Decreased hepatic blood flow
Urinary
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Decreased renal mass
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Decreased glomerular filtration rate
Endocrine
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Decreased insulin secretion
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Decreased glucose tolerance
Nervous system
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Decreased brain mass
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Loss of neurons
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