The atypical antipsychotic drug olanzapine may be effective for the relief of nausea and vomiting unrelated to chemotherapy in patients with advanced cancer, US research suggests

A small trial involving 30 patients with advanced cancer found that a low dose (5mg daily) of olanzapine produced significant improvement in the persistent nausea and vomiting that had been present in the absence of chemotherapy or radiotherapy.

During seven days of treatment, the patients who took olanzapine showed a significant reduction in nausea scores within one day from a baseline level of 9/10 to 2/10, whereas a placebo group showed no change in nausea scores.

At the same time, patients receiving olanzapine reported less use of other antiemetic drugs, increased appetite and better well-being.

And interestingly, although olanzapine is usually associated with sedation, the cancer patients taking it reported lower levels of sedation and less fatigue .

This might be due to reduction in use of other anti-emetic drugs, the study authors said. Similarly, the increase in appetite was not unexpected since this is seen in its use in schizophrenia and biopolar disorder, they said.

The findings, published in JAMA Oncology, suggest that the use of olanzapine as a treatment for nausea be explored in larger and longer duration studies, said study author Dr Charles Loprinzi a Mayo Clinic medical oncologist.

“Current guidelines for the management of nausea and vomiting in patients with advanced cancer have not specifically indicated that one drug looks substantially better than a variety of other drugs,” said Dr Loprinzi.

“However, we believe the present results may be viewed as a best practice for treating nausea and vomiting in patients with advanced cancer-associated nausea and vomiting.”

“And as a generic drug, [olanzapine] is also relatively affordable, with a one-month supply often costing anywhere from $10 to $15,” he added.