Olanzapine for the Relief of Nausea in Patients With Advanced Cancer and Incomplete Bowel Obstruction

Bowel obstruction is one of the most common complications in patients with advanced cancer. Incomplete bowel obstruction is one of the leading causes of nausea and vomiting, which may result in a substantial impairment to quality of life. We explored the antiemetic activity of olanzapine against nausea and vomiting in cancer patients with incomplete bowel obstruction. This retrospective study was carried out on a palliative care unit, using an electronic medical record from 2007 to 2009. The intensity of the symptom was evaluated and classified from the medical records on four scales. The frequency of vomiting also was noted from the medical records. During this study period, 20 patients met the inclusion criteria. The average dose of olanzapine was 4.9 ± 1.2 mg and treatment duration was 23.4 ± 16.2 days. Olanzapine treatment led to a significant decrease in the average intensity score of nausea from 2.4 ± 0.7 to 0.2 ± 0.4 (P < 0.001). Of the 20 patients, 18 (90%) experienced a reduction in the intensity of nausea. The average frequency of vomiting significantly decreased after olanzapine treatment from 1.1 ± 1.3 times/day (median 0.5; range 0–4) before the treatment to 0.3 ± 0.5 times/day (median 0; range 0–1) after the treatment (P < 0.01). Before the treatment, 10 patients experienced vomiting; eight of these patients experienced a decrease in the frequency of vomiting with olanzapine treatment. Our study suggests the potential efficacy of olanzapine for relief of nausea in incomplete bowel obstruction. A prospective trial is promising.