Geriatrics is defined as 65 years of age and older. With the baby boomer adult population entering their "golden years,“ the population of older adults is steadily increasing in the United States.1 According to the Center for Disease Control's (CDC) review of public health and aging, the median age of the world's population is increasing.1 The percentage of the population of 65 years and older in the United States is projected to increase from 12.4% in the year 2000 to 19.6% in the year 2030, which will increase demands in medical care.1 This chapter will focus on appropriate prescribing principles in the elderly, as well as provide an overview of the management of Alzheimer dementia and Parkinson disease.
Polypharmacy is defined as taking nine or more medications.2-3 Chronic illness among geriatric patients comes with a risk for increased numbers of medications, which potentially lead to polypharmacy and adverse events such as falls, constipation, confusion, and delirium.2-3 Medication-related side effects can often be mistaken as the onset of a new chronic illness or simply the normal aging process. As medications are prescribed for these perceived new conditions, it may precipitate a "prescribing cascade“ in which the provider prescribes one drug to treat the side effects of another medication the patient is taking.4 It has been estimated in the geriatric population, for every dollar spent on medications, as much as $1.30 is spent on treating medication-related side effects.5 Key facts about medication use are:
- Approximately 30% of hospital admissions in geriatric adults are directly related to medications.6
- Studies have also shown that a 4% chance of experiencing an adverse drug reaction exists with administration of five medications.7
- The risk of a medication-related adverse event increases to as high as 28% when taking 11 to 15 medications.7
These data significantly support the need for pharmacist intervention in prescribing to the older adult population. Appropriate prescribing of medications is vital to prevent medication-related adverse events due to duplications in therapy, drug-drug and drug-food interactions, inappropriate dosing, as well as polypharmacy.
Appropriate Prescribing in the Older Adult
Special consideration must be taken when prescribing medications in the geriatric population.8 The original Beers criteria outlined medications to avoid in the elderly9-11 (Table 65-1). The Beers list includes medications such as propoxyphene and cyclobenzaprine.9 Propoxyphene, which is considered ineffective for pain management, causes very similar side effects in the elderly as other narcotic analgesics.9 Cyclobenzaprine is also on the Beers list due to an unfavorable side effect profile and metabolism to a tricyclic antidepressant.9 The 2009 publication by Beers and colleagues identifies preferred medications when prescribing central nervous system targeted medications9-11 (Table 65-2). Examples of these agents include extended-release galantamine, memantine as add-on therapy for advanced dementia, as well as citalopram for treatment ...