Q: Assume if you don't have luxury of time - and - you have to send patient for CT scan with IV contrast, who has listed allergy to IV contrast. What would be your recommendation?

Answer:

200mg Hydrocortisone IV 4 hours (or as soon as possible) before injection. Also, 50mg Benadryl (Diphenhydramine) IV/PO before (or as soon as possible) 1 hour of the injection.

If time permits, ideal would be to give 50mg Prednisone PO 13, 7 and 1 hour before the injection. And, 50mg Benadryl (Diphenhydramine) IV/PO before 1 hour of the injection.