Yoodee, J., Permsuwan, U., & Nimworapan, M. (2017). Efficacy and safety of olanzapine for the prevention of chemotherapy-induced nausea and vomiting: A systematic review and meta-analysis. Critical Reviews in Oncology/Hematology, 112, 113–125.

STUDY PURPOSE: The primary aim of this systematic review was to compare the efficacy and safety of olanzapine with standard antiemetics.

TYPE OF STUDY: Systematic review/meta-analysis

DATABASES USED: MEDLINE, EMBASE, SCOPUS, Cochran Central Register of Controlled Trials

YEARS INCLUDED: Inception to July 15, 2016

INCLUSION CRITERIA: The studies of interest were those that reported either olanzapine as add-on treatment (dexamethasone plus 5-HT₃ antagonist, with or without NK1 antagonist) or olanzapine monotherapy compared to standard treatment. 

EXCLUSION CRITERIA: Duplicate data and non-English language studies.

TOTAL REFERENCES RETRIEVED: 573

EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Two independent reviewers

FINAL NUMBER STUDIES INCLUDED: 16 studies however, only 9 were pooled for statistical analysis because 1 was an observational study, and 6 clinical trials did not have a comparison group. 

TOTAL PATIENTS INCLUDED IN REVIEW 1,308 (in the 9 studies included in analysis) 

SAMPLE RANGE ACROSS STUDIES: 17-380

KEY SAMPLE CHARACTERISTICS: Multiple tumor types, focused on patients receiving olanzapine.

PHASE OF CARE: Active anti-tumor treatment

The results of the combined studies included in the meta-analysis showed that CR (defined as no emesis and no rescue drugs) was achieved more frequently for delayed CINV (RR = 1.77, 95% CI [1.07, 1.49]) and overall CINV (RR = 1.32; 95% CI [1.08, 1.62]). Olanzapine was not superior to traditional antiemetic therapy for acute CINV. The most frequently occurring adverse events were drowsiness and constipation.

• Limited number of studies included
• High heterogeneity
• Multiple measures used to determine the presence of nausea and vomiting.

Nurses caring for patients with delayed CINV can consider the use of olanzapine, but also must recognize the common occurring drowsiness and constipation with the use of the medication.