Premedication regimens for patients allergic to intravenous contrast
| Elective (12- or 13-hour) regimen |
| Oral regimens |
| Prednisone 50 mg at 13 hours, 7 hours, and 1 hour before contrast administration, with or without diphenhydraminea 50 mg 1 hour before contrast administration |
| Methylprednisolone 32 mg at 12 and 2 hours before contrast administration, with or without diphenhydraminea 50 mg 1 hour before contrast |
| Intravenous regimen (for patients unable to take medications by mouth) |
| Hydrocortisone 200 mg at 13 hours, 7 hours, and 1 hour before contrast administration, with or without diphenhydraminea 50 mg 1 hour before contrast administration |
| Emergency regimen |
| Methylprednisolone 40 mg or hydrocortisone 200 mg immediately, then every 4 hours until contrast administration, with or without diphenhydraminea 50 mg 1 hour before contrast administration |
↵a The addition of diphenhydramine is optional. Evidence on its value is mixed.
Based on information in reference 8.