Most people undergoing chemotherapy receive anti-nausea (anti-emetic) medications to prevent nausea and vomiting. These drugs, given alone or in combination, can be taken in pill form or administered through a vein in your arm.Your doctor advises which to use based on the treatment you're receiving.Medications used to prevent nausea and vomiting include: 1  Alprazolam (Niravam, Xanax). 2  Aprepitant (Emend).3  Dexamethasone.hese drugs, given alone or in combination, can be taken in pill form or administered through a vein in your arm. Your doctor advises which to use based on the treatment you're receiving. Medications used to prevent nausea and vomiting include: 1  Alprazolam (Niravam, Xanax). 2  Aprepitant (Emend). 3  Dexamethasone.