Lower Dose of Nausea, Vomiting Drug Controls Chemo Symptoms

A lower dose of olanzapine was as effective in treating chemotherapy-related nausea and vomiting as the standard dose.

A lower dose of olanzapine, a drug used to treat nausea and vomiting, may provide similar effectiveness compared with the standard dose in patients with solid tumors who were currently being treated with chemotherapy likely to cause nausea and vomiting, according to recent study findings.

Although olanzapine is known to be an effective agent to prevent or reduce vomiting and nausea, it may result in substantial daytime drowsiness or a desire to fall asleep (also known as somnolence) when given to patients at the standard dose. According to the National Cancer Institute, olanzapine is originally a drug used to treat certain mental disorders, but it is also being studied as a treatment for nausea and vomiting from some cancer treatments like chemotherapy.

“Our findings suggest that olanzapine 2.5 milligram is noninferior to 10 milligram in antiemetic (a drug to prevent or reduce nausea and vomiting) efficacy and results in reduced occurrence of daytime somnolence (lethargy, drowsiness) among patients receiving highly emetic (can cause vomiting) chemotherapy, and should be considered as a new standard of care,” the researchers wrote in the study published in The Lancet Oncology.

Complete control of vomiting episodes was achieved in 59 of 132 patients (45%) assigned 2.5 milligrams of olanzapine for up to 120 hours compared with 59 of 135 patients (44%) assigned the 10-milligram dose. Significantly fewer patients experience daytime somnolence of any severity in the 2.5-milligram group compared with the 10-milligram group (65% versus 90%). The lower-dose group also had significantly fewer patients experience severe somnolence at day 1 (5% versus 40%).

Researchers conducting this study aimed to compare a low dose with a high dose in patients with solid tumors after receiving highly emetogenic chemotherapy.

In this phase 3 trial, researchers enrolled patients aged 13 to 75 years with an Eastern Cooperative Oncology Group performance status between 0 and 2 (meaning they were either fully active with no restrictions or were ambulatory but unable to carry out work activities), and were being treated with high-dose cisplatin or doxorubicin-cyclophosphamide for a solid tumor.

Patients in this study were randomly assigned to receive low-dose oral olanzapine, which consisted of 2.5 milligrams of the drug, or a standard dose, which was 10 milligrams. The assigned regimen was given to patients for four days with a triple antiemetic regimen.

The primary focus of the study was to assess was complete control, defined as no rescue medications, no vomiting episodes, and either no or mild nausea in the overall phase (0-120 hours). The safety end point of interest for this study was daytime somnolence.

Of the 275 patients enrolled into the study, 134 were assigned to the 2.5-milligram dose of olanzapine and 141 were assigned to the 10-milligram dose.

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