Know your patient’s kidney function
Knowing your patient’s kidney function is an important consideration if a patient is using a medicine that is renally excreted as doses of these medicines may need to be adjusted.1 Checking kidney function is especially important when prescribing for patients who have impaired adaptive and homeostatic mechanisms (e.g. hospitalised, frail older people) and who may be sensitive to small differences in serum levels.2,3
The need for dose adjustment is not always recognised,4 leading to medicines or their metabolites accumulating and causing toxicity, especially if the medicine has a narrow therapeutic index (e.g. digoxin, lithium).5
- Bell JS, Blacker N, Leblanc VT, et al. Prescribing for older people with chronic renal impairment. Aust Fam Physician 2013;42:24–8. [PubMed]
- Australian medicines handbook drug choice companion: aged care: Third Edition. Adelaide: Australian Medicines Handbook Ltd, 2010.
- McLean AJ, Le Couteur DG. Aging biology and geriatric clinical pharmacology. Pharmacol Rev 2004;56:163–84. [PubMed]
- Hanlon JT, Wang X, Handler SM, et al. Potentially inappropriate prescribing of primarily renally cleared medications for older veterans affairs nursing home patient. J Am Med Dir Assoc 2011;12:377–83.[Online]
- Mangoni AA, Jackson SHD. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. Br J Clin Pharmacol 2004;57:6–14. [Online]