<qa>  What is the newest PPI?This study will look at a drug called esomeprazole, the newest PPI, as a way to further reduce the amount of nausea and vomiting seen in breast cancer patients receiving adriamycin or epirubicin chemotherapy. Esomeprazole may help protect the gut lining from the stomach acid and thus lessen the nausea and vomiting. If patients have less stomach sickness, they may be able to enjoy their daily routines much more while they are getting chemotherapy. 