Antipsychotic Drug Controls "Breakthrough" Nausea and Vomiting after ChemotherapyIn a phase III clinical trial, the antipsychotic drug olanzapine (Zyprexa) was significantly more effective than metoclopramide (Reglan) in controlling chemotherapy-induced nausea and vomiting (CINV) that occurs in some patients despite preventive treatment for these side effects. (Olanzapine is approved by the Food and Drug Administration to treat schizophrenia and bipolar disorder.) Dr. Rudolph Navari of Indiana University School of Medicine-South Bend presented the results at a May 16 press briefing held in advance of the American Society of Clinical Oncology (ASCO) annual meeting .
The double-blinded randomized trial is the first study to demonstrate an effective treatment for "breakthrough" CINV, defined as nausea and vomiting that persist despite preventive treatments. About 30 to 40 percent of patients receiving certain chemotherapy drugs experience breakthrough CINV, which usually develops 2 to 4 days after treatment.
Dr. Navari and his colleagues studied 80 patients who developed breakthrough vomiting or nausea after treatment with chemotherapies that are known to induce vomiting, such as cisplatin, cyclophosphamide, and doxorubicin. Patients were randomly assigned to receive either daily oral olanzapine (10 mg) for 3 days or oral metoclopramide (10 mg) three times per day for 3 days.
During the 72-hour follow-up period, 71 percent of patients receiving olanzapine had no vomiting, compared with 32 percent of patients receiving metoclopramide. Olanzapine prevented nausea in 67 percent of patients, versus 24 percent for metoclopramide. The differences between the two treatment groups were statistically significant, and neither drug caused severe side effects.
"The recommendation from ASCO and other international guidelines is to use your best antiemetics up front," explained Dr. Navari. "Then, if patients develop breakthrough nausea and vomiting, there really haven't been any good options." Metoclopromide is often used in such cases, "but it hasn't been that effective," he said.
The results "are a great step forward for quality of life for our patients," Dr. Sandra Swain, ASCO president-elect, said at the press briefing. For some patients, breakthrough CINV is so debilitating that they will "opt out of curative treatment," she added.