For Transplant Patients, Oral Antinausea Drug May Be Cheaper, Just as Effective
Key Words: antiemetic drugs, chemotherapy, leukemia, nausea, radiation therapy, side effects. (Definitions of many terms related to cancer can be found in the Cancer.gov Dictionary.)
Severe nausea and vomiting are common, debilitating side effects of high-dose chemotherapy and radiation regimens. Drugs known as serotonin antagonists have been shown to prevent or reduce the severity of chemotherapy-induced nausea and vomiting. Recent studies have shown that these "antiemetic" drugs, ondansetron and granisetron, are equally effective whether given intravenously (directly into a vein) or orally (by mouth).
For patients receiving high-dose chemotherapy or radiation to prepare them for a bone marrow transplant (BMT), however, intravenous antiemetics have generally been assumed to be better than oral agents at controlling nausea and vomiting. Now the results of a recent study challenge this assumption.
The study, published in the November 2001 issue of the journal Biology of Blood and Marrow Transplantation, found that an intravenous antiemetic drug was not significantly more effective than oral antinausea medication in this group of patients (see the journal abstract).
"This study did not show significant superiority for the intravenous antiemetic regimen," said Michael Fisch, M.D., M.P.H., assistant professor of medicine specializing in palliative care and rehabilitation at the University of Texas M. D. Anderson Cancer Center in Houston. "It is a single study and it does not prove oral agents are equivalent to intravenous antiemetics. That being said, I think this study supports a broader comfort zone for the use of oral agents to control nausea and vomiting in the BMT setting."
Oral antiemetics have several potential advantages over those given intravenously, Fisch said. Because patients take the medication at home, oral agents do not require nursing time, supplies or space at the treatment center. "This may mean that it is less expensive to use oral antiemetics if patients can swallow and absorb pills."
The study involved 102 patients who were being treated with high-dose chemotherapy before bone marrow transplantation. Researchers randomly assigned them to receive intravenous ondansetron, oral ondansetron or oral granisetron to control nausea and vomiting. The study was double-blinded, which means neither patients nor doctors knew who was receiving which drug.
Patients were treated for between four and eight days. At the end of each treatment day, patients placed a mark on a visual scale to indicate the degree of nausea they experienced that day. While patients were at the treatment center, nurses recorded episodes of vomiting and also noted whether patients needed "rescue" antiemetics (different than what they were taking in the study). Outpatients recorded this information themselves at home in the evening.
When the results were analyzed, almost exactly the same proportion of patients in each treatment group experienced either a complete response (minimal or no nausea) or a major response (one episode of vomiting or no vomiting but moderate nausea). Patients' self-reports of nausea were also similar on all three regimens.
"Patients did relatively well for the first three days of this study regardless of the antiemetic regimen or preparative [chemotherapy] regimen used," writes lead author Mary P. Fox-Geiman, who led the team that conducted the study at Loyola University Medical Center in Maywood, Illinois.
By day four, however, response rates had declined and most patients needed rescue antiemetics. This decline over time mirrors that seen in other studies of antiemetics in the BMT setting, the authors write.
The researchers also compared the costs of administering the three antiemetic regimens. They found that intravenous ondansetron was the most costly regimen and oral ondansetron the least costly. "All three regimens had similar efficacy in this BMT population; oral ondansetron was the most cost-effective," they conclude.
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