HPE Managing CINV pocket guide 2019 | Page 52

of schedules classifying chemotherapeutics according to their likelihood of emesis following treatment with particular agents. 1,3,4 Chemotherapy agents are divided into four categories based on the percentage of patients with the risk of emesis caused by single agents in the absence of antiemetic prophylaxis. 2 Many chemotherapeutic agents (including parenteral and oral therapy) have been added over time: 7 • Highly emetic (HEC): >90% risk of emesis (for example, cisplatin, dacarbazine, epirubicine >90mg/ m²) • Moderately emetic (MEC): >30–90% risk of emesis (for example, busulfan, dinutuximab, temozolomide) • Low emetic (LEC): 10–30% risk of emesis (for example, thiotepa, mitoxantrone, tisagenlecleucel) • Minimally emetic (MiEC): 0<10% risk of emesis (for example, vincristine, daratumumab, bevacizumab). This four-level classification schedule is used in international antiemetic guidelines for both intravenous and oral chemotherapeutics. 5–9 When using combination regimens, the emetogenic level is determined by identification of the most emetogenic agent in the combination followed by assessment of the relative contribution of the other agents. As an example, doxorubicin <60mg/m² and cyclophosphamide ≤1500mg/m² are both defined as moderate emetogenic agents. 7 However, when used in combination, their regimen is defined as highly emetogenic. Prevention and treatment Prevention of nausea and vomiting is considered to be the key to effective control of CINV. Antiemetics are most effective when they are used prophylactically. Once nausea and vomiting occur, they become more difficult to suppress and it might increase the spectrum of other antiemetics required in future chemotherapy cycles. The three drug classes with the highest therapeutic index 52 | 2019 | hospitalpharmacyeurope.com