Polypharmacy in Older Adult Cancer Patients

Polypharmacy, the use of multiple drugs to manage disease states, is a predominant  feature within contemporary healthcare. It is one of the most distinguishing factors differentiating care of older patients from the care of younger ones, as it is associated with the presence of comorbidity. Indeed, 39% of elderly Americans consume five or more drugs on a routine basis.[1] With heightened drug consumption comes increased risk for adverse  sequelae. 

Older patients may fail to consume their medications as prescribed because of faulty memory, a lack of understanding about the treatments they are being given and their importance, or concerns about cost. Nonadherence to the prescribed regimen may impact their treatment outcome. Toxicity profiles may be altered (often heightened) as a result of altered pharmacodynamics. Drug interactions may be responsible for admission to the acute care setting and prolong the length of hospitalization. Additionally, overall treatment efficacy-and ultimately, patient survival-may be compromised.

Polypharmacy has significant implications in gerooncology. More than 80% of older adults with cancer have comorbid conditions that require prescription medicines to control their course.[2] Additionally, the active management of cancer requires considerable polypharmacy. Combination chemotherapy is more common than monotherapy in the treatment of most malignancies. A significant armamentarium of supportive care drugs is required to manage the physical sequelae of therapy-related toxicities (ie, antiemetics, growth factors, antibiotics) and the emotional demands of recovery (ie, antianxiety agents, antidepressants, antidiarrheals, sleep enhancers). In the advent of progressing or advanced cancer, yet another cadre of drugs is subsequently employed to manage distress and enhance comfort (ie, analgesics, laxatives, appetite stimulants). Hence, for oncology nurses working predominantly with adults facing cancer, awareness of polypharmacy and its potential implications within clinical practice is a much needed competency. Nevertheless, there is a considerable lack of knowledge and investigation into the implications of polypharmacy in the care of older adults with cancer.[3–5]

While drug-interaction concerns are germane to all patients undergoing treatment for cancer,[6] they have particular relevance in geriatric oncology owing to the predominance of polypharmacy within this patient cohort. A recent report by a multidisciplinary panel of Dutch pharmacists and medical oncologists has provided us with an important first step at evaluating and quantifying drug interactions within clinical oncology settings.[7] Following an extensive literature review, interactions were classified by level of evidence using a structured assessment format. (See Table I and Table II of the article by Jansman et al.[7]) A total of 88 drug interactions were identified. Of these, 38 were classified as clinically significant, which was defined as necessitating an alert or intervention (ie, dose adaptation, discontinuation, additional monitoring). (These key interactions are listed in Table IV of the article by Jansman et al.[7]) It is highly recommended that this information be shared with pharmacy and physician colleagues and that it become the basis of treatment guidelines integrated into clinical settings.

References:

References

1. Jorgensen T, Johannsson S, Kennerfalk A, et al: Prescription drug use, diagnoses, and healthcare utilization among the elderly. Ann Pharmacother. 35(9):1004–1009, 2001. PUBMED2. Yancik R, Ganz PA, Varicchio CG, et al: Perspectives on co-morbidity and cancer in older adults: Approaches to expand the knowledge base. J Clin Oncol. 19(4):1147–1151, 2001. PUBMED3. Girre V, Arkoub H, Puts M, et al: Potential drug interactions in elderly cancer patients. Crit Rev Oncol Hematol. 78: 220–226, 2011. PUBMED4. Lichtman SM, Boparai MK: Anticancer  drug therapy in the older cancer patient: Pharmacology and polypharmacy. Curr Treat Opin Oncol. 9(2-3):191–203, 2008. PUBMED5. Tranchand B, Laporte S, Glehen O, et al: Pharmacology of cytotoxic agents: A helpful tool for building dose adjustment guidelines in the elderly. Crit Rev Oncol Hematol. 48(2):199–214, 2003. PUBMED6. Riechelmann RP, Saad ED: A systematic review on drug interactions in oncology. Cancer Invest. 24(7):704–712, 2006. PUBMED7. Jansman FGA, Reyners AKL, van Roon EN, et al: Consensus-based evaluation of clinical significance and management of anticancer drug interactions. Clin Ther. 33(3):305–314, 2011. FULL TEXT