© Geriatric Times. All rights reserved.
Safe Prescribing: Interdisciplinary Solutions
by Mark Monane, M.D., and Lisa A. Cataldi, M.P.H.
| Geriatric Times |
 |
May/June 2000 |
|
Vol. I |
|
Issue 1 |
Despite the widespread use of prescription drugs by the aged population,
prescribing for the elderly may be less than optimal. Factors such as patient
age, multiple diseases and disease severity, use of multiple medications, and
physicians' lack of training in geriatrics contribute to placing elderly
individuals at increased risk of developing adverse drug events (ADEs).
ADEs are defined as noxious and unintended patient events: symptoms, signs
or laboratory abnormalities caused by a drug (Naranjo et al., 1992). They may
result in significant morbidity, mortality and cost (Bates et al., 1997).
Better understanding of the challenges associated with prescribing for the
elderly will allow clinicians to develop and implement strategies for optimal
prescribing.
Age-Related Changes
The incidence of ADEs in the community-dwelling elderly varies widely from
5% to as much as 35% (Hanlon et al., 1997), with differences attributed to
various methods used to ascertain these events (Hanlon et al., 1994).
Interestingly, as a result of underreporting and mistakenly attributing
symptoms to medical conditions or the aging process overall, the prevalence of
ADEs in the elderly may be underestimated (Chrischilles et al., 1992).
Common physiologic changes that accompany the aging process often alter the
pharmacokinetic and pharmacodynamic properties of many drugs (Golden et al.,
1999; Lindley et al., 1992). As a result, the processes of drug absorption,
distribution, metabolism and excretion may sometimes be disrupted (Committee on
Pharmacokinetics and Drug Interaction in the Elderly, 1997), resulting in a
complication.
Multiple Diseases
Multiple disorders and severity of each disease also may contribute to the
increased likelihood for ADEs in the elderly. For example, the concordance of
osteoarthritis and congestive heart failure-two common disorders in the
ambulatory elderly population-can lead to the prescription of both a
nonsteroidal anti-inflammatory class of pain medications and a diuretic for
fluid-overload management. The combination of these two necessary medications
is a precursor for an ADE-especially when two treating physicians independently
prescribe for the same patient.
In addition, the numerous other medications needed to treat these conditions
are associated with a higher incidence of ADEs in the elderly (Grymonpre et
al., 1988; Hallas et al., 1990; Hutchinson et al., 1986).
ADE risk increases with each additional medication prescribed (Hanlon et
al., 1997). The paradox, however, is that the multiple use of medications, or
polypharmacy, for disease management in a given elderly patient can be a
desirable situation.
Yet, polypharmacy with duplicative or interacting medications should be
avoided. In fact, elderly people living in the community take an average of 4.5
medications per day (Schwartz, 1997), and institutionalized elders average
eight prescriptions each day (Ferrini and Ferrini, 1993).
Lack of Geriatric Expertise
Compounding these challenges is a general lack of geriatric training in both
medical and pharmacy education (General Accounting Office, 1995). Sixty-eight
percent of visits by elderly people to office-based physicians are associated
with initiation or continuation of a prescribed medication (Woodwell, 1999).
Many of these physicians may not have received geriatric training, thereby
increasing the risk of suboptimal prescribing for their elderly patients.
Without appropriate training in geriatric pharmacology, physicians may be
unaware that some medications are particularly prone to ADEs (Monane et al.,
1998a).
Below-Optimal Prescribing
In a 1991 study, investigators from the department of medicine at the
University of California, Los Angeles used a Delphi survey method to develop 30
criteria sets to identify potentially inappropriate medications in elderly
nursing home patients (Beers et al., 1991). Their recommendation focused on
drugs that should be avoided, excessive dosing and excessive duration of
treatment in 15 common medical conditions.
In 1997, Beers published an updated recommendation that identifies 28
criteria for suboptimal prescribing in elderly outpatients. Wilcox et al.
(1994) applied these criteria to 6,171 non-institutionalized elderly from the
1987 National Medical Expenditure Survey. The researchers concluded that nearly
one-fourth of all elderly people living in the community were prescribed an
inappropriate medication.
More recently, Golden et al. (1999) found that nearly 40% of 2,193 homebound
elderly individuals were prescribed an inappropriate drug according to the
Beers criteria.
Finding the Solution
Clearly, there is opportunity to improve prescribing to this population.
Yet, given the pervasiveness of suboptimal prescribing across the United States
and the likelihood of this problem expanding as the population continues to
age, finding a far-reaching solution seems quite challenging.
In 1995, Merck-Medco Managed Care, L.L.C., a large pharmacy benefit manager
with 10 million elderly members, launched Partners for Healthy Aging to reduce
potentially unsafe or ineffective prescriptions for the elderly. This unique
program includes an educational approach combined with online computerized drug
utilization review (DUR) to provide patient-specific messages to pharmacists
and physicians prior to dispensing prescription medications. The initiative
represents a significant step toward improving pharmacotherapy among the
community-based elderly population.
Drug Utilization Review
A concurrent DUR program is effective in reducing inappropriate prescribing
in the elderly. Mandated by state pharmacy law, DUR applies explicit criteria
to patient prescription and medical history information (Monane et al., 1998a).
The utilization review focuses on safety, appropriateness, effectiveness and
cost-containment (Lindley et al., 1992) to determine potentially inappropriate
prescribing such as drug interactions, contraindications, overdoses,
underutilization and overutilization (Monane et al., 1998b).
One method uses online database prescriptions for evaluation of quality of
care. When the DUR program detects a potential problem, a warning message is
sent to the pharmacist, who then contacts the physician to review the
prescription and to encourage appropriate changes. DUR programs are not
substitutes for careful consideration by physicians and pharmacists. Instead,
they are a mechanism for sending alerts about potentially inappropriate
medications (Beers, 1997).
In 1995, the Merck-Medco department of medical affairs, with support from an
external medical advisory board, developed senior-specific DUR criteria to
detect potentially inappropriate drugs in the elderly (Monane et al., 1998a).
Based on Beers' criteria (Beers et al., 1991), these senior-specific rules
cover three DUR categories: drug-age, maximum daily dose and drug-disease. An
example of each rule (alert) is presented in the Table.
Monane et al. (1998a) focused on the drug-age rules and demonstrated that
the DUR component of Partners for Healthy Aging significantly reduces the use
of potentially harmful medications by seniors. The study evaluated 43,007 mail
service prescriptions for more than 23,000 patients, age 65 years and older,
whose prescription benefits are managed by Merck-Medco. In those cases where a
potentially harmful prescription was identified and our pharmacists were able
to discuss the criteria with the physician, the Partners for Healthy Aging
program changed prescriptions 24% of the time to prevent potential harm from
drugs or drug dosages generally recognized in the medical literature as
inappropriate for patients over 65. That 24% change rate is 12 times greater
than the 3% change in prescribing found in a similar intervention study
(Soumerai and Avorn, 1986).
Summary
The elderly population is the fastest growing segment in the United States
(U.S. Census Bureau, 1996), and seniors are the largest users of prescription
drugs. As described above, the elderly remain at risk for adverse drug events.
Given the common changes that occur with age, the prevalence of multiple
chronic diseases requiring multiple medications, as well as the lack of
geriatric expertise in ambulatory care, we are faced with a major
challenge.
Efforts to optimize medication use in this population through a partnership
between patients, pharmacists and physicians is needed. Programs like Partners
for Healthy Aging link information on geriatric prescribing with the
opportunity to change prescribing as appropriate. Such programs can optimize
medication management in the elderly by identifying potential problems and
empowering health care providers to improve prescribing in this special
population.
Dr. Monane is medical director for the Partners for Healthy Aging program
at Merck-Medco Managed Care, L.L.C.
Ms. Cataldi is research project manager in the Center for Outcomes
Measurement and Performance Assessment at Merck-Medco Managed Care,
L.L.C.
References
Bates DW, Spell N, Cullen DJ et al. (1997), The costs of adverse drug events
in hospitalized patients. Adverse Drug Events Prevention Study Group. JAMA
277(4):307-311 [see comments].
Baum C, Kennedy DL, Forbes MB, Jones JK (1984), Drug use in the United
States in 1981. JAMA 251(10):1293-1297.
Beers MH (1997), Explicit criteria for determining potentially inappropriate
medication use by the elderly. An update. Arch Intern Med
157(14):1531-1536.
Beers MH, Ouslander JG, Rollingher I et al. (1991), Explicit criteria for
determining inappropriate medication use in nursing homes. UCLA Division of
Geriatric Medicine. Arch Intern Med 151(9):1825-1832.
Chrischilles EA, Segar ET, Wallace RB (1992), Self-reported adverse drug
reactions and related resource use. A study of community-dwelling persons 65
years of age and older. Ann Intern Med 117(8):634-640 [see comments].
Committee on Pharmacokinetics and Drug Interaction in the Elderly (1997),
Pharmacokinetics and Drug Interactions in the Elderly and Special Issues in
Elderly African-American Populations: Workshop Summary. Washington, D.C.:
Institute of Medicine.
Ferrini AF, Ferrini RL (1993), Health in the Later Years. 2nd ed. Madison,
Wisc.: Brown & Benchmark.
General Accounting Office (1997), Prescription Drugs and the Elderly.
Washington, D.C.: U.S. General Accounting Office, Document GAO/HEHS-95-152.
Golden AG, Preston RA, Barnett SD et al. (1999), Inappropriate medication
prescribing in homebound older adults. J Am Geriatr Soc 47(8):948-953.
Grymonpre RE, Mitenko PA, Sitar DS et al. (1988), Drug-associated hospital
admissions in older medical patients. J Am Geriatr Soc 36(12):1092-1098.
Hallas J, Harvald B, Gram LF et al. (1990), Drug related hospital
admissions: the role of definitions and intensity of data collection, and the
possibility of prevention. J Intern Med 228(2):83-90.
Hanlon JT, Schmader KE, Koronkowski MJ et al. (1997), Adverse drug events in
high risk older outpatients. J Am Geriatr Soc 45(8):945-948 [see comment].
Hanlon JT, Schmader KE, Lewis JK (1994), Adverse drug reactions. In:
Therapeutics in the Elderly, Delafuente JC, Stewart RB, eds. Cincinnati: Harvey
Whitney Books, pp212-224.
Hutchinson TA, Flegel KM, Kramer MS et al. (1986), Frequency, severity and
risk factors for adverse drug reactions in adult out-patients: a prospective
study. J Chronic Dis 39(7):533-542.
Lindley CM, Tully MP, Paramsothy V, Tallis RC (1992), Inappropriate
medication is a major cause of adverse reactions in elderly patients. Age
Ageing 21(4):294-300.
Monane M, Matthias DM, Nagle BA, Kelly MA (1998a), Improving prescribing
patterns for the elderly through an online drug utilization review
intervention: a system linking the physician, pharmacist, and computer. JAMA
280(14):1249-1252 [see comments].
Monane M, Nagle B, Kelly MA (1998b), Pharmacotherapy: strategies to control
drug costs in managed care. Geriatrics 53(9):51-64.
Naranjo CA, Shear NH, Lanctor KL (1992), Advances in the diagnosis of
adverse drug reactions. J Clin Pharmacol 32(10):897-904.
Office of National Cost Estimates (1999), National health expenditures,
1988. Health Care Financ Review 11(4):1-41.
Schwartz JB (1997), Geriatric Clinical Pharmacology. In: Textbook of
Internal Medicine, Kelly WN, DuPont HL et al., eds. Philadelphia:
Lippincott-Raven, pp2547-2554.
Soumerai SB, Avorn J (1986), Economic and policy analysis of
university-based drug "detailing." Med Care 24(4):313-331.
U.S. Bureau of the Census (1996), Population Projections of the United
States, by Age, Race, and Hispanic Origin: 1993 to 2050. Washington, D.C.: U.S.
Government Printing Office; Current Population Reports, ser. P-25, No. 104.
Wilcox SM, Himmelstein DU, Woolhandler S (1994), Inappropriate drug
prescribing for the community-dwelling elderly. JAMA 272(4):292-296.
Woodwell DA (1999), National Ambulatory Medical Care Survey: 1997 Summary.
Advanced Data 305:1-25.