Trimethobenzamide (Tebamide, Tigan) is an antiemetic used to prevent nausea and vomiting. It is often prescribed for patients with gastroenteritis, medication-induced nausea, and other illnesses. Trimethobenzamide is generally considered the most potent antiemetic that does not have effects on the serotonergic, dopaminergic, or histaminergic systems, so it has a lower likelihood of causing undesired side effects. In the United States, it requires a prescription.