Polypharmacy Assessment Is an Important Part of Radiation Therapy for Elderly Patients

Documentation and Review: Make a List 

Documentation of medication is not a billable service and is time consuming.¹ But it is crucially important in protecting elderly patients.

Elderly patients with known or suspected polypharmacy should undergo a medication review before radiotherapy is initiated.¹ These are best led by pharmacists but can be conducted between oncology nurses and patients.¹

The first step in identifying and managing polypharmacy is to interview patients to help them compile a detailed, clear, and current list of the prescription and over-the-counter medications and nutritional and herbal supplements they are taking.^1,2 (Patients should be encouraged to carry a current list of their medications, in case of emergencies.) The use of a centralized pharmacy improves the likelihood that drug incompatibilities will be spotted, but patients should also be asked about their use of herbal supplements, which also can alter drug metabolism and efficacy. Medication lists should be reviewed and updated at each radiotherapy appointment.¹ The reviews are an opportunity to spot signs of new cognitive impairment or confusion, just as observing the patient at arrival can help detect new balance and gait issues, for example.

Identify Unneeded Drugs

Reducing the number of medications patients are taking is the first step toward optimizing medication use. It can reduce their burdens of toxicity, functional impairment, and out-of-pocket costs, and improve compliance and drug efficacy.^1,2 Stuart Lichtman, MD, of Memorial Sloan Kettering Cancer Center encourages cancer treatment teams to question, for example, the importance of cholesterol-lowering drugs for patients with advanced-stage tumors undergoing palliative care.²

Interdisciplinary teams should assess which medications can be discontinued to reduce the risk of drug-drug interactions or cumulative risks.¹ 

There are 3 frequently used polypharmacy assessment tools that can help evaluate for polypharmacy and inappropriate prescribing, although none of them are specific to radiation oncology patients:^1,8-10

• The Beers Criteria for Inappropriate Medication Use in Older Patients makes specific recommendations about prescribing for different elderly patient populations.
• The Medication Appropriateness Index (MAI) is a 10-item questionnaire to score prescription appropriateness, including questions to identify unnecessary duplication of prescriptions and cost.
• STOPP and START (Screening Tool of Older Person’s Potentially Inappropriate Prescriptions and Screening Tool to Alert Doctors to the Right Treatment, respectively) Criteria are organ-specific criteria and medication lists.

Radiotherapy and Polypharmacy: Spotting Risks and Toxicities

Medications that are frequently prescribed to help manage radiotherapy side effects, including antiemetics, opioids, and corticosteroids, can increase the risk of adverse drug reactions in polypharmacy patients. Cumulative risks should be minimized where possible.¹ For example, anorexia drugs prescribed to help manage weight loss associated with acute oral and other toxicities can increase elderly patients’ risk of thrombosis.¹ Particularly in the context of polypharmacy, benzodiazepines for nausea and anxiety management can increase patients’ risk of cognitive impairment, delirium, falls, and bone fractures.¹ Anticholinergics, such as hydroxyzine and promethazine, prescribed for radiation cystitis can contribute to the risk of cognitive impairment and constipation.¹

In combination, these and other medications’ potential for adverse effects increase. Prescriptions should be reviewed with a patient’s comorbidities in mind, and anticipated radiotherapy-associated signs and symptoms should be shared with the entire treatment team so that polypharmacy-associated reactions can be more quickly identified.¹

These responsibilities are shared across the cancer care team but the radiation oncology nurse is well situated to spot polypharmacy-associated complications of radiotherapy.

References

1. Novak J, Goldberg A, Dharmarajan K, et al. Polypharmacy in older adults with cancer undergoing radiotherapy: a review. J Geriatr Oncol. 2022;13:778-783. doi: 10.1016/j.jgo.2022.02.007
2. Lichtman SM. Polypharmacy: geriatric oncology evaluation should become mainstream. J Clin Oncol. 2015;33(13):1422-1423. doi:10.1200/JCO.2014.60.3548
3. Assari S, Bazargan M. Race/ethnicity, socioeconomic status, and polypharmacy among older Americans. Pharmacy (Basel). 2019;7(2):41. doi:10.3390/pharmacy7020041
4. Nieder C, Mannsaker B, Pawinski A, Haukland E. Polypharmacy in older patients ≥70 years receiving palliative radiotherapy. Anticancer Res. 2017;37(2):795-799. doi:10.21873/anticancres.11379
5. Lembrecht Jorgensen T, Hallas J, Land LH, Herrstedt J. Comorbidity and polypharmacy in elderly cancer patients: the significance of treatment outcome and tolerance. J Geriatr Oncol. 2010;1(2):87-102. doi:10.1016/j.jgo.2010.06.003
6. Magne N, Bouleftour W, Daguenet E, et al. Assessing toxicities of curative radiotherapy combined with concomitant non anti-cancer drugs: a sub-analysis of the prospective epidemiological RIT trial. Radiother Oncol. 2022;168:23-27. doi:10.1016/j.radonc.2022.01.012
7. VanderWalde NA, Williams GR. Developing an electronic geriatric assessment to improve care of older adults with cancer receiving radiotherapy. Techn Innov Patient Support Radiat Oncol. 2020;16:24-29. doi:10.1016/j.tipsro.2020.09.002
8. 2019 American Geriatrics Society Beers Criteria® Update Expert Panel. American Geriatrics Society 2019 updated AGS Beers Criteria® for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2019;67(4):674-694. doi:10.1111/jgs.15767
9. Hanlon JT, Schmader KE, Samsa GP, et al. A method for assessing drug therapy appropriateness. J Clin Epidemiol. 1992;45(10):1045-1051. doi:10.1016/0895-4356(92)90144-c.
10. O’Mahony D, Gallagher P, Ryan C, et al. STOPP & START criteria: a new approach to detecting potentially inappropriate prescribing in old age. Eur Geriatr Med. 2010;1(1):45-51. doi:10.1016/j.eurger.2010.01.007