Nausea can be treated with one of the following: Hydroxyzine 25 to 50 mg orally every 6 hours Metoclopramide 10 to 20 mg orally every 6 hours An antiemetic phenothiazine (eg, prochlorperazine 10 mg orally or 25 mg rectally every 6 hours) Ondansetron 4 mg orally or IV every 8 hours Itching is caused by histamine release and may be relieved by an antihistamine (eg, diphenhydramine 25 to 50 mg orally or IV).