changes that occur with age affect pharmacokinetics and pharmacodynamics
in elderly patients. A decrease in creatinine clearance (although not
invariable) occurs commonly with increasing age at the rate of 7.5 to
10 mL/min per decade of life and necessitates adjustment in the dosage
of renally excreted drugs. Aging is associated with an increase in the body
fat compartment, resulting in a larger volume of distribution for lipid-soluble
drugs; at the same time, the water compartment decreases, resulting in an
increased concentration of water-soluble drugs. Gastrointestinal changes are
not significant and do not alter drug absorption with normal aging. Albumin
levels do not change appreciably with age alone; any decrease usually results
- Decline in creatinine clearance with an increase in age.
1. Dharmarajan TS, Tota R. Appropriate prescribing of medications in older adults. Fam Pract Recert 2000;22:29-38.
2. Leipzig RM. Pharmacology and appropriate prescribing. In: Cobbs EL, Duthie EH, Murphy JB, editors. Geriatrics review syllabus, 4th ed. Dubuque (IA):
Kendall/Hunt Publishing Co; 1999:30-5.
3. Schwartz JB. Clinical pharmacology. In: Hazzard WR, Blass JP, Ettinger WH, et al, editors. Principles of geriatric medicine and gerontology. 4th ed. New York: McGraw-Hill, Health Professions Division; 1999:303-31.
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