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www.TheOncologyPharmacist.com setron, or ondansetron) for as needed (prn) use on days 2 and 3. Palonosetron has a half-life of 40 hours, and the granisetron patch is designed to stay in place for 5 days; thus, a second serotonin antagonist would be an ineffective rescue agent during these corresponding time periods. An evidence-based alternative would be to prescribe a prn agent from a different class, such as dexamethasone (if not already scheduled for use), or a dopamine RA (eg, metoclopramide) or phenothiazine (eg, prochlorperazine). A reference list of classes of antiemetics and corresponding agents is available in the National Comprehensive Cancer Network Antiemesis guidelines at www.nccn.org. Cost of therapy Cost is also an important consideration in making decisions about antiemetic therapies. For oral medications, individual pharmaceutical companies offer financial assistance for those in the greatest financial need, including the uninsured as well as underinsured individuals with high copayments and low income levels. These can be accessed via company websites. Organizations such as the American Cancer Society, the Leukemia and Lymphoma Society, the Patient Assistance Foundation, and the Patient Advocacy Network offer copayment assistance that is not strictly need-based. For individuals with high copayments for oral medications, using available IV formulations (eg, fosaprepitant IV on day 1 instead of aprepitant PO) may be one alternative to help diminish out-of-pocket expenses, as facility-administered medications are often better covered.
Source: Reference 10.
Figure 2. Multinational Association of Supportive Care in Cancer (MASCC) Antiemesis Tool
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Comorbidities and concomitant medications Comorbidities and concomitant medications are of special concern in older patients receiving chemotherapy, as the elderly have a high incidence of comorbid disease and are more likely to be using other medications.11 Approximately 40% of individuals 65 years and older take 5 or more prescription medications; thus, drug–drug interactions and polypharmacy warrant careful attention. Jakobsen and Herrstedt discuss these concerns in detail in their excellent review of CINV in the elderly cancer patient, and a few examples warrant mention.11 Caution is advised when using extended dexamethasone in individuals taking chronic nonsteroidal anti-inflammatory drugs, given the elevated risk of gastric bleeding. At a minimum, gastrointestinal prophylaxis with proton pump inhibitors should be considered. Diabetics should monitor their blood sugars more closely given corticosteroids’ effects on raising plasma glucose levels. For individuals with seizure disorders, metoclopramide and prochlorperazine should be used with caution, given the increased risk for con-
vulsions. Interestingly, the risk for extrapyramidal side effects with metoclopramide is greater in younger as compared to older individuals. Aprepitant has a number of drug–drug interactions listed in its package insert.12 International normalized ratio levels should be monitored closely when aprepitant and warfarin are concomitantly used, given the slight lowering of warfarin plasma levels. Antiemetic guidelines already take into consideration the drug–drug interaction between corticosteroids and aprepitant with their recommendations for dexamethasone dosing, given the approximate 50% increase in corticosteroid levels when aprepitant is used. Conclusion Oncology nurses play a critical role in optimizing the prevention and management of CINV. Careful, proactive, and iterative assessment, ongoing and interactive communication with patients and families, and up-to-date knowledge of available therapeutic agents and considerations with respect to cost, comorbidities, and concomitant medications are all essential to ensuring the best possible outcomes for patients receiving chemotherapy. Fortunately, numerous resources are available to the practicing nurse, including web-based guidelines. Nurses can play a key role in overcoming barriers to optimal CINV prevention and management by helping to standardize care through the adaptation and implementation of evidence-based recommendations in their practice setting. ● References 1. Bender CM, McDaniel RW, Murphy-Ende K, et al. Chemotherapy-induced nausea and vomiting. Clin J Oncol Nurs. 2002;6(2):94-102. 2. Grunberg SM. Obstacles to the implementation of antiemetic guidelines. J Natl Compr Canc Netw. 2009; 7(5):601-605. 3. Stricker CT, Eaby B. Chemotherapy-Induced Nausea and Vomiting. A Guide to Oncology Symptom Mana gement. Pittsburgh, PA: Oncology Nursing Society Press; 2009:91-122. 4. Hawkins R, Grunberg S. Chemotherapy-induced nausea and vomiting: challenges and opportunities for improved patient outcomes. Clin J Oncol Nurs. 2009;131:54-64. 5. Roscoe JA, Bushunow P, Morrow GR, et al. Patient expectation is a strong predictor of severe nausea after chemotherapy: a University of Rochester Community Clinical Oncology Program study of patients with breast carcinoma. Cancer. 2004;101(11):2701-2708. 6. Stricker CT, Velders L. Predictors of chemotherapyinduced nausea and vomiting in women with early stage breast cancer [abstract]. Support Care Cancer. 2005; 13(6):422. 7. Johnson GD, Moore K, Fortner B. Baseline evaluation of the AIM Higher Initiative: establishing the mark from which to measure. Oncol Nurs Forum. 2007;34(3):729-734. 8. Dibble SL, Casey K, Nussey B, et al. Chemotherapyinduced vomiting in women treated for breast cancer. Oncol Nurs Forum Online. 2004;31(1):E1-E8. 9. Dibble SL, Isreal J, Nussey B, et al. Delayed chemotherapy-induced nausea in women treated for breast cancer. Oncol Nurs Forum Online. 2003;30(2):E40-E47. 10. Molassiotis A, Coventry PA, Stricker CT, et al. Validation and psychometric assessment of a short clinical scale to measure chemotherapy-induced nausea and vomiting: the MASCC Antiemesis Tool (MAT). J Pain Symptom Manage. 2007;34(2):148-159. 11. Jakobsen JN, Herrstedt J. Prevention of chemotherapy-induced nausea and vomiting in elderly cancer patients. Crit Rev Oncol Hematol. 2009;71(3):214-221. 12. Emend capsules [package insert]. Whitehouse Station, NJ: Merck & Co., Inc. 2010.
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