Anti-psychotic medication helps control breakthrough CINV
CHICAGO — The anti-psychotic medication olanzapine helps to control breakthrough chemotherapy-induced nausea and vomiting that develops when patients do not respond to conventional prophylactic antiemetic treatments, according to results of a phase 3 trial.
Chemotherapy-induced nausea and vomiting (CINV) affects up to 90% of patients who undergo certain types of chemotherapy, according to background information provided by researchers. About one-third of those patients experience breakthrough CINV.
Olanzapine (Zyprexa, Eli Lily) has been shown to be safe and effective for the prevention of CINV. Researchers hypothesized that olanzapine also may be an effective rescue medication for patients who receive guideline-directed CINV prophylaxis but still experience nausea and vomiting.
Rudolph M. Navari, MD, PhD, clinical director of the Harper Cancer Institute at Indiana University School of Medicine-South Bend, and colleagues conducted a double-blind, randomized controlled trial to compare olanzapine to metoclopramide, which often is prescribed as a treatment for breakthrough CINV despite a lack of research proving its efficacy for that purpose.
Researchers enrolled 205 patients with a median age of 56 years who received guideline-recommended drugs to prevent CINV prior to undergoing their first round of chemotherapy. Eighty of those patients developed breakthrough CINV. Those patients then were randomly assigned to olanzapine 10 mg orally daily for 3 days (n=42) or metoclopramide 10 mg three times a day (n=28) for 3 days. Researchers followed the patients for 72 hours through phone calls from study nurses, and the patients also were asked to keep diaries of their experiences.
Thirty (71%) of the patients assigned to olanzapine experienced no vomiting, compared with 12 (32%) of the patients assigned to metoclopramide, a statistically significant difference. Sixty-seven percent of patients assigned to olanzapine reported experiencing no nausea, compared with 24% of patients assigned to metoclopramide, also a statistically significant difference.
Both treatments were well tolerated, researchers said.
Olanzapine, an FDA-approved treatment for psychosis, causes a variety of side effects when taken daily for 6 months or longer. However, no patients assigned to short-term treatment in this study reported grade-3/grade-4 toxicities, the researchers said.
Because breakthrough CINV typically develops between the second and fourth days after the start of chemotherapy, patients would not have to take olanzapine for longer than 3 days, Navari said in a press release.
“This is the first time that breakthrough CINV has been studied in a systematic way,” Navari said. “This study suggests that olanzapine will be very useful in these patients who feel very sick and sometimes come to the clinic, hospital or emergency room.”