INTRAVENOUS PREMEDICATION
200 mg of hydrocortisone IV 13 hours, 7 hours, and 1 hour prior 50 mg Diphenhydramine (Benadryl®) - optional IV, IM, or PO 1 hour prior

EMERGENCY PREMEDICATION
40 mg IV Methylprenisolone sodium succinate (Solu-Medrol) OR 200 mg IV Hydrocortisone sodium succinate (Solu-Cortef) q4hours until study
50 mg Diphenhydramine (Benadryl®) IV 1 hour prior to contrast injection


ALTERNATIVE ORAL REGIMENS
32 mg PO Methylprednisolone 12 h and 2 h prior 
50 mg Diphenhydramine (Benadryl®) IV, IM, or PO 1 h prior
If allergic to methylprednisolone, aspirin, or NSAID give: 7.5 mg IV Decadron OR 6.0 mg IV Betamethasone q4hours until study.

NOTE
Steroid must be given 4 -6 hours pre contrast to be effective

Pre-medication may help reduce, but does not eliminate, the risk of a serious contrast reaction in a patient considered to be at elevated risk. It mostly reduces chance of minor risks.