Most of the conclusions concerning drug equivalence, dosage, and schedules are based on intravenous administration. An emerging body of formal trials is now becoming available concerning the oral route compared with the intravenous in the administration of various serotonin receptor antagonists. All of these agents have undergone pharmacologic testing. Large, randomized studies have shown that, in the settings of both highly emetogenic chemotherapy and chemotherapy of intermediate emetogenicity, a single dose of oral granisetron demonstrates similar efficacy when compared with a single intravenous dose of ondansetron. Again, similar efficacy was reported.
Corticosteroids also have a high therapeutic index when used for acute chemotherapy-induced emesis.
Issues of equivalence and route of administration, as well as drug dose and schedule, are discussed together. At equivalent doses, corticosteroids have equivalent safety and efficacy and can be used interchangeably. The corticosteroids most frequently studied for use as antiemetics have been dexamethasone 106-111 and methylprednisolone. Some reports have used prednisone. Although efficacy has been reported with these agents, there have been no comparison trials.