Geriatric Patients With Cancer and the Problem of Polypharmacy

A Conversation With Andrew M. Whitman, PharmD


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Andrew M. Whitman, PharmD

Andrew M. Whitman, PharmD

Older patients with cancer generally have multiple comorbidities, with each often requiring separate medications. Studies have shown that polypharmacy and inappropriate drug use are prevalent among older cancer patients, leading to an enormous amount of preventable adverse events, many requiring hospitalization. Although polypharmacy is noted as a serious problem in the oncology community, it remains understudied. To shed light on this important clinical issue, The ASCO Post recently spoke with Andrew M. Whitman, PharmD, an oncology resident in the Department of Pharmacy Services at the University of Virginia Health System in Charlottesville, who recently published an article on the topic of polypharmacy and medication screening tools for older patients with cancer.

Interest in Pharmacy and Geriatrics

Please tell the readers a bit about your background.

I went to pharmacy school at Virginia Commonwealth University in Richmond, Virginia, and while I was getting my doctor of pharmacy degree, I had a unique opportunity to do a combined-degree program, which is a PharmD and a Certificate in Aging Studies. It gave me the chance to delve into complex geriatric principles and how they relate to pharmacy, which became a large focus of my work.

How did you become interested in studying the issue of polypharmacy?

Upon starting my residency at the University of Virginia, it set the stage for working with older patients. During my second year of residency in oncology, I had the opportunity to work with Erika Ramsdale, MD, who already had a well-established geriatric oncology clinic, and spent 1 day a week there. When I started in the clinic, I wanted to find the best way to use my pharmacy degree, and it was decided to look at the issue of polypharmacy. We began a literature search to see what tools were being used for screening and assessment and found it lacking.

Defining Polypharmacy

First, please define polypharmacy and speak a bit about its prevalence in the geriatric oncology setting.

There are many definitions of polypharmacy that vary slightly, and currently there isn’t one consensus-driven definition, yet it is commonly described as using five or more medications. Polypharmacy should consider appropriateness in addition to quantity; therefore, polypharmacy and potentially inappropriate medications should be considered along a spectrum. For example, if you have an 82-year-old woman with cancer and she’s only on one medication, diphenhydramine, for sleep, I’d consider that polypharmacy due to the inappropriateness of the medication. In terms of prevalence, according to the literature,1 it ranges from about 20% in the general population and up to 70% to 100% in patients with cancer. When we screened our older patients with cancer for inappropriate medication use coming into the clinic, we found 100% polypharmacy.

De-prescribing Often Overlooked

You’ve identified a problem called “prescribing cascades” and a solution called “de-prescribing.” Please describe these two terms.

Older oncology patients tend to have multiple comorbidities that often necessitate numerous chronic medications. Of course, many patients also require medications to deal with the side effects of their treatments. For example, an elderly patient comes to the clinic for chemotherapy and develops nausea, which may be addressed with ondansetron, but unfortunately, it has its own side effects. Then there are headaches, constipation, and so on, which are often handled with medications that all have side effects. So, it’s a complicated balancing act.

If you have an 82-year-old woman with cancer and she’s only on one medication, diphenhydramine, for sleep, I’d consider that polypharmacy due to the inappropriateness of the medication.
— Andrew M. Whitman, PharmD

This is where de-prescribing—a stepping-down process that is often overlooked—comes in. One of the most important things driving de-prescribing is simply to look at the indication and the reason the medication was prescribed. Also, it’s important to know the overall goals of the medications being used for a particular patient. This is very important, especially in older patients with cancer, who, because of the intensity of their treatments, are at greater risk for adverse drug events. The purpose of de-prescribing is to hone down the number of inappropriate medications a patient is taking, and there is a surprising amount of overuse.

Screening Tools

Please identify and speak about current tools that busy community doctors can use to screen and address issues of polypharmacy.

Although there are a number of screening tools, the first thing a community oncologist can do is assess medication quantity. If a patient is using five or more medications, it’s a pretty good indicator of potential polypharmacy. At that point, the physician can reach for a screening tool.

Probably the best known of these tools is the Beers Criteria, which was developed in 1991 and has been revised four times, most recently in 2015. Its criteria are based on expert consensus and extensive literature review. It screens for potentially inappropriate medications and has been found to detect the highest prevalence of polypharmacy.2 Naturally, no one tool is perfect, and there are others to choose from. The Medication Appropriateness Index measures appropriateness of medications based on a 3-point scale of a 10-item checklist. For each item, the medication can be deemed appropriate, marginally appropriate, or inappropriate on the basis of such criteria as indication, effectiveness, dosage, directions, and cost.

Another tool that is quite interesting is called START/STOPP [Screening Tool to Alert Doctors to Right Treatment/ Screening Tool of Older Patients’ Prescriptions]. START is a comprehensive tool used to determine the appropriateness of the initial prescribing of medications, whereas STOPP evaluates existing medication regimens. Both tools use evidence-based rules to avoid commonly encountered instances of potentially inappropriate medications and prescribing omissions. START consists of 22 criteria organized by a physiologic system, and STOPP incorporates 65 criteria that are also organized by a physiologic system, with additional focus on analgesics, duplicate drug classes, and drugs that increase the risk of falls.

These tools are a good start, and I use them to perform an initial medication assessment. Of course, incorporating a pharmacist into the clinic setting as part of a multidisciplinary team is the ideal approach. A combination of screening tools may also be incorporated into a clinical support tool in the electronic health record to save time and initiate conversations about de-prescribing.

Closing Thoughts

Would you like to share some last thoughts on this issue?

Polypharmacy and inappropriate use of medications are significant issues that go underreported. To enhance the quality of care, screening patients for polypharmacy should be integrated into a multidisciplinary assessment. And as our population ages, we will see a natural growth in older patients with cancer, making the use of screening tools even more vital. Moreover, studies have shown that screening for polypharmacy and inappropriate use of medications drive down health-care costs by decreasing the number of hospital emergency room visits due to drug-related adverse events.1 There should be more exposure of this topic in the oncology community and approached with significantly more urgency. Polypharmacy is a quality-of-life issue. ■

Disclosure: Dr. Whitman reported no potential conflicts of interest.

References

1. Nightingale G, Hajjar E, Swartz K, et al: Evaluation of a pharmacist-led medication assessment used to identify prevalence of and associations with polypharmacy and potentially inappropriate medication use among ambulatory senior adults with cancer. J Clin Oncol 33:1453-1459, 2015.

2. Price SD, Holman CD, Sanfilippo FM, et al: Association between potentially inappropriate medications from the Beers criteria and the risk of unplanned hospitalization in elderly patients. Ann Pharmacother 48:6-16, 2014.



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