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210 PA R T I I / Physiologic and Pathologic Responses
drug may exert the same therapeutic effect in an older person as a 3. Berry, A. L., & Davignon, D. (1991). Changes with aging. In M. Patrick,
standard dosage in a younger person. S. L. Woods, R. Craven, J. Rokosky, & P. Bruno (Eds.), Medical-surgical
nursing (2nd ed., pp. 55–70). Philadelphia: Lippincott.
With aging, lean body mass decreases by approximately 10% 4. Kenny, R. A. (1985). Physiology of aging. Clinics in Geriatric Medicine, 1,
and body fat increases by the same amount. This, along with de- 37–60.
creased total body water, may also contribute to the retention of 5. Lakatta, E. G., & Levy, D. (2003). Arterial and cardiac aging: Major share-
fat-soluble drugs, so that they exert effects over a longer period of holders in cardiovascular disease enterprises. Part II: The aging heart in
7
7
time because of depot action. health: Links to heart disease. Circulation, 107, 346–354.
6. Lakatta, E. G. (2000). Cardiovascular aging in health. Clinics in Geriatric
Medicine, 16, 419–444.
6
6
Drug Metabolism and Excretion 7. Taffet, G. E., & Lakatta, E. G. (2003). Aging of the cardiovascular system.
In W. R. Hazzard, J. P. Blass, J. B. Halter, J. G. Ouslander, & M. E. Tinetti
The effects of aging on drug metabolism depend on the pathway (Eds.), Principles of geriatric medicine & gerontology (5th ed., pp. 403–421).
New York: McGraw-Hill.
of metabolism in the liver. There is evidence that first-phase me- 8.Schwartz, J. B., & Zipes, D. P. (2008). Cardiovascular disease in the eld-
2
tabolism decreases with age. The liver microsomal drug oxida- erly. In P. Libby, R. O. Bonow, D. L. Mann, & D. P. Zipes (Eds.), Braun-
tion/reduction system (P450 system) is responsible for the metab- wald’s heart disease: A textbook of cardiovascular medicine (8th ed., pp.
olism of many drugs. Although drug-metabolizing enzymes in the 1923–1952). Philadelphia: Saunders Elsevier.
cytochrome P450 system do not decrease with age, most studies 9. Lakatta, E. G. (2003). Arterial and cardiac aging: Major shareholders in
cardiovascular disease enterprises. Part III: Cellular and molecular clues to
8
show decreases in drug metabolism by this system. Multiple drug heart and arterial aging. Circulation, 107, 490–497.
7
7
and environmental factors affect the P450 system and likely ex- 10. Cheitlin, M. D. (2003). Cardiovascular physiology – changes with aging.
plain the observed decrease in drug metabolism in older patients. American Journal of Geriatric Cardiology, 12(1), 9–13.
The other route of drug excretion is the kidney. As was previ- 11. Rich, M. W., & Curtis A. B. for the PRICE-IV investigators. (2007).
ously described, changes in renal plasma flow and GFR may lead Fourth Pivotal Research in Cardiolgy in the Elderly (PRICE-IV) Sympo-
sium—Electrophysiology and heart rhythm disorders in the elderly:
to decreased excretion of active drug with consequent prolonged Mechanisms and management. American Journal of Geriatric Cardiology,
half-lives of drugs and sustained or increased levels of free drug in 16(5), 304–314.6 6
the serum. 12. Bilato, C., & Crow, M. T. (1996). Atherosclerosis and vascular biology of
aging. Aging, 8, 221–234.
As a result of these changes in absorption, distribution, me- 13. Nagai, J., Metter, E. J., & Earley, C. J., et al. (1998). Increased carotid
tabolism, and excretion, greater care must be exercised with drug artery intimal-medial thickness in asymptomatic older subjects with
administration to older patients. Administering drugs in smaller exercise-induced myocardial ischemia. Circulation, 98, 1504–1509.
doses and less frequently may accomplish an adequate therapeutic 14. Lakatta, E. G., & Levy, D. (2003). Arterial and cardiac aging: Major share-
effect. If adverse reactions or side effects occur, it may be more holders in cardiovascular disease enterprises. Part I: Aging arteries: A “set
up” for vascular disease. Circulation, 107, 139–146.
7
7
prudent to discontinue a suspected drug rather than add another 15. Rooke, G. A. (2000). Autonomic and cardiovascular function in the geri-
drug to counteract the effects. Older people are vulnerable to ad- atric patient. Anesthesiology Clinics of North America, 18, 31–46.
verse effects from drugs for many reasons (e.g., age changes, 16. Dart, A. M., & Kingwell, B. A. (2001). Pulse pressure: A review of mech-
chronic conditions, polypharmacy). Consequently, clinical profes- anisms and clinical relevance. Journal of the American College of Cardiology,
7
7
37, 975–984.
sionals must exercise caution and responsibility when drugs and 17. Gimbrone, M. A. (1999). Vascular endothelium, hemodynamic forces,
older adults are concerned. and atherogenesis. American Journal of Pathology, 155, 1–5.
18. Thompson, A. B., Scholer, S. G., & Daughton, D. M., et al. (1992). Al-
tered epithelial lining fluid parameters in old normal individuals. Journal
7
SUMMARY of Gerontology, 47, 171–176.
7
19. Chobanian, A. V., Bakris, G. L., Black, H. R., et al. (2003). The seventh
report of the Joint National Committee on Prevention, Detection, Evalu-
Cardiovascular function declines progressively with age, and be- ation, and Treatment of High Blood Pressure: The JNC 7 Report. JAMA,
cause of the inter-relatedness of the major systems, it is affected by 289, 2560–2572.
and affects the other systems as well. Respiratory, renal, and he- 20. Sharma, G., & Goodwin, J. (2006). Effect of aging on respiratory system
patic functions are independent and interconnected with cardio- physiology and immunology. Clinical Intervention in Aging, 1(3),
253–260.
vascular function so that normal age-related changes in any or all 21. McClaran, S. R., Babcock, M. A., & Pegelow, D. F., et al. (1995). Longi-
of these systems exacerbate changes in other systems. One signif- tudinal effects of aging on lung function at rest and exercise in healthy ac-
icant area in which this interconnectedness is exemplified is in tive fit elderly adults. Journal of Applied Physiology, 78, 1957–1968.
drug therapy. The ongoing question and dilemma for the health 22. Zeleznik, J. (2003). Normative aging of the respiratory system. Clinics in
Geriatric Medicine, 19, 1–18.
care provider is differentiating between decline in function that 23. Pride, N. B. (2005). Ageing and changes in lung mechanics. European
occurs with age and problems resulting from specific cardiovascu- Respiratory Journal, 26(4), 563–565.
6
6
lar diseases. 24. Wiggins, J. (2003). Changes in renal function. In W. R. Hazzard, J. P.
Blass, & J. B. Halter, et al. (Eds.), Principles of geriatric medicine & geron-
tology (5th ed., pp. 543–549). New York: McGraw-Hill.
R EFE R E NC ES 25. Miller, M. (2003). Disorders of fluid balance. In W. R. Hazzard, J. P. Blass,
& J. B. Halter, et al. (Eds.), Principles of geriatric medicine & gerontology
1. Cristofalo, V. J., Gerhard, G. S., & Pignolo, R. J. (1994). Molecular biol- (5th ed., pp. 581–592). New York: McGraw-Hill.
4
4
ogy of aging. Surgical Clinics of North America, 74, 1–21. 26. Hall, K. E. (2003). Effect of aging on gastrointestinal function. In W. R.
2. Kane, R. L., Ouslander, J. G., Abrass, I. B., & Kane, R. (2004). Essentials Hazzard, J. P. Blass, & J. B. Halter, et al. (Eds.), Principles of geriatric med-
of clinical geriatrics (5th ed.). New York: McGraw-Hill. icine & gerontology (5th ed., pp. 593–600). New York: McGraw-Hill.

