Can olanzapine preserve life quality in cancer patients undergoing abdominal radiation therapy?

Abstract

Nausea and vomiting, are the distressing symptoms of radiation therapy in cancer patients. About 40–80% of cancer patients may experience nausea and vomiting during abdominal radiotherapy. Studies revealed that majority of patients do not achieve complete control of nausea and vomiting while using standard anti-emetic regimens. American Society of Clinical Oncology highlights radiotherapy induced nausea and vomiting (RINV) as an understudied area. Nausea and vomiting induced by radiation therapy is underestimated and under-treated by physicians. This affects quality of life and also delay in completion of the subsequent radiation schedules in some patients. Olanzapine, an atypical anti-psychotic agent approved by FDA in 1996, has shown promising results in both prevention and rescue of chemotherapy induced nausea and vomiting (CINV). But its role in RINV has not yet been studied. Olanzapine, because of its action on multiple receptors, especially, those mediating nausea and vomiting (D2, 5-HT2C, and 5-HT3 receptors) is expected to exert an anti-emetic action. Olanzapine also increases appetite, acting via the H1, 5-HT2B, and 5-HT2C receptors. Therefore we hypothesis that olanzapine can accomplish better control of nausea and vomiting in cancer patients undergoing radiation therapy since it has inhibitory activity on neurotransmitters at multiple receptors involved in nausea and vomiting. In addition, it will also improve their quality of life in cancer patients.