Addressing Polypharmacy, PIMs in Geriatric Patients With Cancer

In a narrative review published in The Journal of Geriatric Oncology, researchers outlined available studies assessing the effects of interventions aimed at reducing the burden of polypharmacy and potentially inappropriate medications (PIMs) among older adults with cancer.

Based on their analyses, investigators concluded that implementing services to address polypharmacy and PIMS in both acute and ambulatory settings can help identify drug-related problems (DRPs) and mitigate adverse effects. In addition, applying more than 1 polypharmacy assessment tool increases the capability to identify more PIMs and increases the ability for interventions.

Polypharmacy is generally defined as the concurrent use of 5 or more medications and predominately affects adults 65 years and older, authors explained. PIMs can fall under the category of polypharmacy and include medications that interact with other medications and/or disease states. PIMs can also lack evidence-based indications and may have treatment risks that outweigh benefits.

“While older adults comprise 14.9% of the United States population, they account for 34% of prescription medications and 30% of over-the-counter (OTC) medications,” researchers wrote. Compounding this issue, older adults with cancer are at a higher risk of polypharmacy due to the accumulation of other comorbidities requiring treatments. It is estimated that anywhere from 8% to 84% of older adults with cancer deal with polypharmacy and between 11% and 63% take PIMs.

“Addressing polypharmacy, PIMs, and other DRPs can be challenging not only because of the number of medications used but also because of the multilayered process of managing many comorbidities between specialists, primary care physicians, and allied health professionals,” authors wrote.

Two recently published meta-analyses have shown polypharmacy is associated with chemotherapy-related adverse events (AEs), postoperative complications, functional impairment, and shortened survival, and PIMs and polypharmacy have been linked with reduced quality of life.

However, because older patients are more likely to have comorbidities and functional impairment to begin with, confounding may have been present in some studies. Analyses also have yet to establish a cause-and-effect relationship between polypharmacy/PIMs and poor outcomes, warranting more intervention-based research.

A lack of definitive recommendations from national and international guidelines regarding the optimal strategy for implementing interventions marks a challenge in addressing these issues.

“No single assessment tool comprehensively addresses all DRPs, including polypharmacy or PIM use, so the best practice recommendations are to apply them in combination,” researchers noted. These can include Beer’s Criteria, Medication Adherence Index (MAI), or Screening Tool to Alert Doctors to Right Treatment/Screening Tool of Older Person’s Prescriptions (START/STOPP). All 3 tools also have strengths and weaknesses when it comes to use in older patients with cancer. For example, some tools may not account for OTC or herbal supplementation patients may take.

According to authors, the ultimate goal when applying any of these tools is to identify and discontinue unnecessary medications or those that pose greater risks than benefits to the patients. To do so, and so as to not abruptly stop medications and risk withdrawal or resurgence of an underlying illness, providers can deprescribe medications.

“Deprescribing systematically facilitates medication discontinuation by slowly tapering and continuously reassessing to reduce any potential harms from stopping treatment,” they explained. To assist providers, several international guidelines exist including the comprehensive geriatric assessment (CGA) and the comprehensive medication review (CMR).

However, no universal recommendation exists as to which provider (eg, clinical pharmacist, nurse, physician, geriatrician, oncologist) is best suited to address the issue of polypharmacy.

Several interventional studies have been conducted to answer this question. Results show that despite the pivotal role oncologists play in older patients’ care, “these physicians lack the time and resources to provide formal guidance on adjusting therapy after DRPs hinder interventions in practice.”

The incorporation of polypharmacy and PIM assessment tools into clinical practice may help providers better identify and manage DRPs, but these can be difficult to implement. Abbreviated assessment tools have been studied for this purpose, although they may not be sufficient when used alone.

An additional analysis found that a pharmacist-led CMR carried out with multiple assessment tools was highly effective in identifying PIMsS, “although data regarding modifications of therapy was unreported.” Enhanced communication of CGA and CMR results between the patient and care teams could also assist in deprescribing.

Researchers underscored the need for an interprofessional team with expertise in each assessment domain, combining the knowledge of oncologists, geriatricians, nurses, and pharmacists, to mitigate polypharmacy and PIMS outcomes.

Overall, given the many limitations present in the analyses included in the review, authors noted the critical need for additional literature assessing interventions in these patients.

“Future investigators should consider the development of a polypharmacy and PIM assessment tool that is specific to older adults with cancer as their medication care varies greatly from the average older adult without cancer, as does their prognosis and performance status,” they said.

“The high degree of pharmacist-driven interventions reported in the literature opens a window of opportunity to expand [clinical pharmacy services] into diverse practice settings to optimize outcomes for older adults with cancer,” authors concluded.

Reference

Barlow A, Prusak ES, Barlow B, Nightingale G. Interventions to reduce polypharmacy and optimize medication use in older adults with cancer. J Geriatr Oncol. 2021;12(6):863-871. doi:10.1016/j.jgo.2020.12.007