Oncology Patient Evidence-Based Notes (OPEN): antiemetics for chemotherapy-induced nausea and vomiting.

Since the 1990s, new antiemetic agents have significantly reduced the incidence of nausea and vomiting associated with chemotherapy. Specifically, these agents are the serotonin receptor antagonists and consist of dolasetron (Anzamet, Aventis Pharmaceuticals, Bridgewater, NJ), granisetron (Kytril, Roche Pharmaceuticals, Nutley, NJ), ondansetron (Zofran, GlaxoSmithKline, Research Triangle Park, NC), and tropisetron (Navoban, Novartis Pharmaceuticals, Auckland, New Zealand [this product currently is not marketed in the United States]). A new class of agents, substance P/neurokinin 1 receptor antagonists, also is being used in combination with other antiemetics to prevent acute and delayed chemotherapy-induced nausea and vomiting. An example of this type of agent is aprepitant (Emend, Merck & Co., Inc., Whitehouse Station, NJ). As a result of the numerous agents now available, the American Society of Clinical Oncology developed an expert panel consisting of individuals from medical oncology, oncology nursing, radiation oncology, pediatric oncology, and oncologic pharmacy practice to review the literature on antiemetic therapy and create evidence-based clinical practice guidelines for the use of antiemetics during oncologic treatment (Gralla et al., 1999). A MEDLINE literature search was performed by the panel using the following keywords or phrases: antiemetics, neoplasms, adverse effects, anticipatory plus nausea, anticipatory plus vomiting, serotonin antagonists, phenothiazines, butyrophenones, cannabinoids, corticosteroids, and metoclopramide. Based on the best available evidence and the panel’s best clinical judgment, clinical guidelines with levels of evidence were developed. Level I is the strongest evidence and is composed of randomized, controlled trials or meta-analyses of well-designed, controlled trials. Level V is the weakest evidence and is composed of expert opinions or case reports (Agency for Health Care Policy and Research, 1994) (see Figure 1).