Uses: This medication is used to treat nausea and vomiting that can occur following surgery or with certain stomach/intestinal problems (e.g., gastroenteritis). Treating vomiting quickly can prevent a serious loss of body water (dehydration). Trimethobenzamide belongs to a class of drugs known as antiemetics. It works by decreasing the signals in the brain that lead to vomiting. Trimethobenzamide injection must not be used in children.