Efficacy of olanzapine for the prophylaxis of chemotherapy-induced nausea and vomiting: a meta-analysis.

AIM: The aim of the present study was to evaluate the efficacy of olanzapine for the prevention of chemotherapy-induced nausea and vomiting (CINV).

METHODS: The literature was searched for randomized controlled trials (RCTs) evaluating the efficacy of olanzapine for the prophylaxis of CINV using PubMed, Embase, Central, as well as clinicaltrials.gov for unpublished studies. The endpoints of the study were the number of patients who achieved a complete response (CR; no emesis and no rescue) and no nausea in the acute, delayed and overall phases. Two authors independently selected studies, assessed the risk of bias and extracted data. The included RCTs were analysed using RevMan 5.3 provided by the Cochrane Collaboration.

RESULTS: Ten RCTs were identified for the meta-analysis. Compared with other antiemetic agents, olanzapine significantly improved the CR in the delayed and overall phases, but did not enhance the CR in the acute phase. For the control of CINV, olanzapine was better than and comparable with aprepitant in the acute phase and delayed phase, respectively. Compared with placebo, treatment with 5 mg and 10 mg olanzapine exhibited similar efficacy in terms of the CR in the delayed and overall phases.

CONCLUSIONS: Olanzapine is an excellent alternative for the prophylaxis of CINV. Olanzapine 5 mg per day should be recommended as the initial dose because of equivalent efficacy to a 10 mg dose but a lower potential risk of side effects. Further studies are needed to explore the optimal combination of medicines.