ASCO--Two randomized trials have shown that an oral serotonin antagonist, granisetron(Drug information on granisetron) (Kytril) tablets, is equal in safety and efficacy to an intravenous drug of the same class in preventing emesis in patients undergoing emetogenic chemotherapy.
In the first study, of highly emetogenic chemotherapy, presented at ASCO by Richard Gralla, MD, 1,054 patients received either two 1 mg granisetron tablets 60 minutes before an initial course of cisplatin(Drug information on cisplatin) (Platinol) or 32 mg of IV ondansetron(Drug information on ondansetron) (Zofran) 30 minutes before cisplatin administration. Placebos were given to allow for blindedness.
Total control rates (defined as no nausea or vomiting and no additional medication) at 24 hours were comparable for both groups: 55% for oral granisetron and 58% for IV ondansetron.
"It is clear that Kytril tablets offer control of nausea and vomiting comparable to intravenous therapy," said Dr. Gralla, director, Oschner Cancer Institute, New Orleans. He also noted that in this study, the cost of the oral agent ($62) was lower than that of the IV drug ($129).
In the second trial, involving moderately emetogenic chemotherapy, the same drug regimens were given to 1,085 patients prior to an initial course of cyclophosphamide(Drug information on cyclophosphamide) or carboplatin(Drug information on carboplatin) (Paraplatin). Again, total control rates were similar, said Edith Perez, MD, associate professor of medicine, Mayo Clinic Jacksonville (Florida), in her ASCO presentation.
At 24 hours, 59% of patients on the oral agent had achieved total control, compared with 58% of those on IV ondansetron. At 48 hours, the figures were 47% and 44%, respectively.
In the cisplatin study, the most common adverse events--headache, asthenia, and constipation--were similar in both antiemetic groups. In the cyclophosphamide/carboplatin trial, the incidence of these side effects was similar in both groups, while IV ondansetron-treated patients had a significantly higher incidence of dizziness and visual disturbances.