Frailty and Potentially Inappropriate Prescribing in Older People with Polypharmacy: A Bi-Directional Relationship?

Frail older adults commonly experience multiple co-morbid illnesses and other risk factors for potentially inappropriate prescribing. However, determination of frailty varies depending on the frailty instrument used. Older people's degree of frailty often influences their care and treatment priorities. Research investigating the association between frailty and potentially inappropriate prescribing is hindered by a wide variety of frailty definitions and measurement tools. We undertook a narrative review of selected articles of PubMed and Google Scholar databases. Articles were selected on the basis of relevance to the core themes of frailty and potentially inappropriate prescribing. We identified observational studies that clearly link potentially inappropriate prescribing, potential prescribing omissions, and adverse drug reactions with frailty in older adults. Equally, the literature illustrates that measured frailty in older adults predisposes to inappropriate polypharmacy and associated adverse drug reactions and events. In essence, there is a bi-directional relationship between frailty and potentially inappropriate prescribing, the underlying substrates being multimorbidity and inappropriate polypharmacy. We conclude that there is a need for consensus on rapid and accurate identification of frailty in older people using appropriate and user-friendly methods for routine clinical practice as a means of identifying older multimorbid patients at risk of potentially inappropriate prescribing. Detection of frailty should, we contend, lead to structured screening for inappropriate prescribing in this high-risk population. Of equal importance, detection of potentially inappropriate prescribing in older people should trigger screening for frailty. All clinicians undertaking a medication review of multimorbid patients with associated polypharmacy should take account of the important interaction between frailty and potentially inappropriate prescribing in the interest of minimizing patient harm.