A consistent definition has not been established for polypharmacy; however, the most commonly cited definition is an instance where the patient is on five or more medications (Caughey, G. E., Kalisch-Ellett, L., Masnoon, N., & Shakib, S., 2017).
Medication use in the elderly requires a different and unique approach due to several factors, including:
All of the above factors cause a change in the way medication interacts with the body. In the hospital setting, it is common for older adults to be discharged with more medications than they arrived with upon admission. Failing to make necessary adjustment(s) to the patient’s treatment regimen while in hospital can lead to higher risk of adverse events and increased morbidity.
All medications have the potential to contribute to adverse drug events. In the elderly person, health care providers need to be aware that the potential for negative consequences is even higher. Clinical consequences of inappropriate prescribing in the elderly include:
(Maher, Hanlon & Hajjar, 2014)
Regular medication reviews should be performed on elderly patients to optimize drug therapy. Comprehensive consideration should be given to medical history, comorbidities, existing clinical evidence and patient/caregiver preferences.
Another approach to optimize medical management in the elderly is to focus on how to choose an appropriate medication to treat specific conditions and whether the evidence exists to support the benefit of the medication. The Beers Criteria for Potentially Inappropriate Medication Use in Older Adults is a guideline for practitioners. It provides a list of medications that might cause more harm than benefit to the elderly. It also outlines medications that should not be chosen in certain underlying medical conditions.
Anticholinergic medications are regularly prescribed to manage conditions such as depression, overactive bladder, psychosis, Parkinson’s disease and allergies. Anticholinergic medications act by directly or indirectly blocking the neurotransmitter acetylcholine in the central or peripheral nervous systems.
These medications are associated with several adverse effects due to their mechanism of action or their unintended anticholinergic activity. Adverse events associated with anticholinergic medications range from peripheral effects such as blurry vision, urinary retention and tachycardia, to central adverse events including memory loss, drowsiness, cognitive impairment, confusion, delirium and falls. Older people are more susceptible to these side effects due to certain age related changes such as decrease in cholinergic neurons or receptors in the brain, reduced hepatic and renal clearance, and frailty.
Anticholinergic burden is the accumulation of higher levels of exposure to one or more anticholinergic medications and the resulting increased risk of medication-related adverse effects (Boustani, Campbell, Munger, Maidment, & Fox, 2008). Accurate quantification of anticholinergic burden is a valuable tool in assessing risks versus benefits of prescribing an anticholinergic drug in elderly population. Various scales have been described in literature. These categorize the anticholinergic medications into groups based on their level of anticholinergic potency (Lozano-Ortega et al., 2019):
2019 American Geriatrics Society Beers Criteria® Update Expert Panel, Fick, D. M., Semla, T. P., Steinman, M., Beizer, J., Brandt, N., Dombrowski, R., DuBeau, C.E., Pezzullo, L., Epplin, J.J., & Flanagan, N. (2019). American Geriatrics Society 2019 updated AGS Beers Criteria® for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society, 67(4),674-694.
Boustani, M., Campbell, N., Munger, S., Maidment, I., & Fox, C. (2008). Impact of anticholinergics on the aging brain: a review and practical application. Aging Health, 4, 311-320.
Carnahan, R. M., Lund, B. C., Perry, P. J., Pollock, B. G., & Culp, K. R. (2006). The Anticholinergic Drug Scale as a measure of drug‐related anticholinergic burden: associations with serum anticholinergic activity. The Journal of Clinical Pharmacology, 46(12), 1481-1486.
Caughey, G. E., Kalisch-Ellett, L., Masnoon, N., & Shakib, S. (2017). What is polypharmacy? A systematic review of definitions. BMC geriatrics, 17(1), 230. doi:10.1186/s12877-017-0621-2
Han, L., Agostini, J. V., & Allore, H. G. (2008). Cumulative anticholinergic exposure is associated with poor memory and executive function in older men. Journal of the American Geriatrics Society, 56(12), 2203-2210.
Hilmer, S. N., Mager, D. E., Simonsick, E. M., Cao, Y., Ling, S. M., Windham, B. G., Harris, T. B., Hanlon, J. T., Rubin, S. M., Shorr, R. I., Bauer, D. C., & Abernethy, D. R. (2007). A drug burden index to define the functional burden of medications in older people. Archives of Internal Medicine, 167(8), 781-787.
Lozano-Ortega, G., Johnston, K. M., Cheung, A., Wagg, A., Campbell, N. L., Dmochowski, R. R., & Ng, D. B. (2019). A review of published anticholinergic scales and measures and their applicability in database analyses. Archives of Gerontology and Geriatrics.
Maher, R. L., Hanlon, J. T., & Hajjar, E. R. (2014). Clinical Consequences of Polypharmacy in Elderly. Expert Opinion on Drug Safety, 13(1), 57-65. doi:10.1517/14740338.2013.827660
Rudolph, J. L., Salow, M. J., Angelini, M. C., & McGlinchey, R. E. (2008). The anticholinergic risk scale and anticholinergic adverse effects in older persons. Archives of Internal Medicine, 168(5), 508-513.