Typical use is the following: Motion sickness: Antihistamines, scopolamine patches, or both Mild to moderate symptoms: Prochlorperazine, promethazine, or metoclopramide Severe or refractory vomiting and vomiting caused by chemotherapy: 5-HT3 antagonists, neurokinin-1 receptor antagonists (eg, aprepitant) Only parenteral or sublingual agents should be used in actively vomiting patients.