| Antihistamines | Diphenhydramine (Benadryl) 25 to 50 mg orally or IV every four to six hours | Oral: $0.16 to $0.24 (generic) or $0.69 to $1.05 (brand) per day | These agents more useful if nausea related to ambulation |
| IV: $1.86 per 50-mg vial (brand) |
| Meclizine (Antivert) 12.5 to 25 mg orally every six to eight hours | Oral: $0.12 to $1.05 (generic) or $1.58 to $3.35 (brand) per day |
| Antipsychotics and related agents | Haloperidol (Haldol) 0.5 to 2 mg orally two to four times per day | Oral: $0.50 to $2.05 per day | Reasonable agent for treating nausea; multiple uses for haloperidol in palliative medicine |
| Prochlorperazine (Compazine) 5 to 10 mg oral or IV every six to eight hours or 25 mg rectally every 12 hours | Oral: $2.67 to $3.24 (generic) or $3.21 to $4.28 (brand) per day | Prochlorperazine less sedating than promethazine |
| IV: $6.70 per 10-mL vial |
| Suppository: $6.44 to $13.78 (generic) or $7.68 (brand) per day |
| Promethazine (Phenergan) 12.5 to 25 mg orally, IV, or rectally every four to six hours | Oral: $1.74 to $3.06 (generic) or 17.49 to $26.24 (brand) per day | Dopamine-blocking properties less than prochlorperazine; more antihistaminic qualities |
| IV: $2.29 (generic) or $2.97 (brand) per 25-mg vial |
| Suppository: $3.37 to $4.46 per dose |
| Prokinetic agents | Metoclopramide (Reglan) 5 to 10 mg orally or IV four times per day | Oral: $0.42 to $1.70 (generic) or $3.12 to $5.04 (brand) per day | Lower doses preferred in older patients; more useful if early satiety is the presenting problem |
| IV: $0.84 (generic) or $2.26 (brand) per 10-mg vial |
| Serotonin antagonists | Granisetron (Kytril) 1 mg orally or IV twice per day | Oral: $104.24 per day | Because of cost, this class best reserved for treatment failures; other serotonin antagonists also available |
| IV: $195.20 per 1-mg single-dose vial |
| Ondansetron (Zofran) 4 mg orally or IV two to four times per day | Oral: $48.47 to $96.94 per day |
| IV: $25.60 per 2-mg single-dose vial |