Drug Name Usual Dosage Range Main Side Effects FDA Pregnancy Category Vitamins and Antihistamines Pyridoxine 25 mg q 8 h PO - A Thiamine1 250 mg IV 3-5 days - A Doxylamine 12.5 mg q 12 h PO or 12.5 mg am and 25 mg pm PO - A Doxylamine- pyridoxine combination 10/10 mg up to 4 tablets (1 tablet am, 1 tablet afternoon, 2 tablets bedtime) PO - A Diphenhydramine 50–100 mg q 4-6 h PO/IM/IV Drowsiness B Dimenhydranate 50–100 mg q 4-6 h PO/PR 50 mg q 4-6 h IV Drowsiness B Meclizine 25 mg every q 4-6 h PO Drowsiness B Dopamine Receptor Antagonist Promethazine 25 mg q 4-6 h PO/IM/IV/PR Sedation, dry mouth, EPS C Prochlorperazine 5-10 mg q 4-6 h (maximum 40 mg/day) PO/IM/IV, 25 mg q 12 h PR   Sedation, dry mouth, EPS C Metoclopramide 5-10 mg q 8 h PO/IM/IV EPS B Chlorpromazine 10-25 mg q 4-6 h PO/IM 50-100 mg q 6-8 h PR 25-50 mg q 4-6 h IV EPS, orthostatic hypotension (IM route), sedation C Droperidol 0.625-2.5 mg IV over 15 minutes, then 1.25 mg or 2.5 mg IM as needed; can be given IV continuously at 1-1.25 mg/h EPS,black box warning ( QT prolongation and torsades de pointes) C Serotonin Antagonist Ondansetron 4-8 mg q 6-8 hPO 4-8 mg q 12 h IV Headache, constipation B Glucocorticoids2 Prednisolone 40-60 mg/day PO (then taper) Cleft palate C Methylprednisolone 16 mg q 8 h PO/IV (2-3 days, then taper over 2 weeks) Cleft palate C PO: oral, am: morning, pm: night, IM: intramuscular, IV: intravenous, PR: rectal, EPS: extrapyramidal symptoms 1dose for the prevention ofwernicke's encephalopathy 2avoid use before 10 weeks of gestation

Table 1: Medications used in the management of nausea and vomiting