Top Line: How effective is olanzapine in managing nausea related to radiation?
The Study: Olanzapine is an effective treatment for refractory nausea in cancer patients, particularly those with chemotherapy induced nausea. Olanzapine is an atypical antipsychotic that is a broad antagonist of multiple receptors implicated in the emetic pathway. In this phase 3 trial, 301 patients receiving abdominal or pelvic radiation were randomized to receive ondansetron (4 mg BID) with or without 5 mg olanzapine once daily during treatment. The goal here was nausea prevention rather than symptomatic treatment. During treatment, significantly more patients in the olanzapine arm reported no or minimal nausea (85.8% v 16.3%) and no or minimal vomiting (95.9% v 74.5%). Olanzapine significantly reduced grade 2+ nausea (7.4% v 67%) and vomiting (1.4% v 7.8%). Among subgroups, rectal cancer patients and concurrent chemotherapy patients saw significant reductions in grade 2+ nausea and vomiting. There were no high grade events related to olanzapine, but there significantly more grade 1 drowsiness, dysarthria, and orthostatic hypotension.
TBL: In this randomized trial, adding olanzapine to ondansetron led to significantly less nausea and vomiting during abdominal and pelvic radiation. While olanzapine was clearly effective at preventing nausea and vomiting, could it also be used as effectively to treat nausea or vomiting after it develops? | Vijayan, Radiother Oncol 2026
The Study: Olanzapine is an effective treatment for refractory nausea in cancer patients, particularly those with chemotherapy induced nausea. Olanzapine is an atypical antipsychotic that is a broad antagonist of multiple receptors implicated in the emetic pathway. In this phase 3 trial, 301 patients receiving abdominal or pelvic radiation were randomized to receive ondansetron (4 mg BID) with or without 5 mg olanzapine once daily during treatment. The goal here was nausea prevention rather than symptomatic treatment. During treatment, significantly more patients in the olanzapine arm reported no or minimal nausea (85.8% v 16.3%) and no or minimal vomiting (95.9% v 74.5%). Olanzapine significantly reduced grade 2+ nausea (7.4% v 67%) and vomiting (1.4% v 7.8%). Among subgroups, rectal cancer patients and concurrent chemotherapy patients saw significant reductions in grade 2+ nausea and vomiting. There were no high grade events related to olanzapine, but there significantly more grade 1 drowsiness, dysarthria, and orthostatic hypotension.
TBL: In this randomized trial, adding olanzapine to ondansetron led to significantly less nausea and vomiting during abdominal and pelvic radiation. While olanzapine was clearly effective at preventing nausea and vomiting, could it also be used as effectively to treat nausea or vomiting after it develops? | Vijayan, Radiother Oncol 2026