Pre-Medication Policy


*Unless in the opinion of the responsible health care professional and supervising radiologist, the potential benefits outweigh the risks i.e. emergency situations.
In these instances, specific indications and reason(s) for exception should be documented in the report.


Premedication with steroids and Benadryl is now recommended only for patients who have had a reaction to contrast of a similar class (iodinated agents are one class, gadolinium based agents are separate class) to the one planned to be given.

Prophylaxis for those with reactions to other allergens is no longer necessary.


This policy decision is based on the following information:

  • Current estimated reaction risk in the general population is about 0.6% (Wang et al.)
  • Only patients with a prior reaction to contrast are known to be at higher risk (3-11% reaction rate, with 2% break-through) (Mervak et al.Lasser et al).
  • The rate of reaction for patients with prior anaphylaxis to substances other then contrast may be higher than the normal population, but this is not proven.
  • The current standard of care in the United States is to premedicate patients with steroids and Benadryl to decrease risk of repeat contrast reaction in patients who have had a reaction in the past to a similar class contrast agent.

References:

Wang CL, Cohan RH, Ellis JH, Caoili EM, Wang G, Francis IR. Frequency, outcome, and appropriateness of treatment of nonionic contrast media reactions. AJR 2008; 191:409–415

Lasser EC, Berry CC, Mishkin MM, Williamson B, Zheutlin N, Silverman JM. Pretreatment with corticosteroids to prevent adverse reactions to nonionic contrast media. AJR 1994; 162:523–526

Mervak BM, Davenport MS, Ellis JH, et al. Breakthrough reaction rates in high-risk inpatients premedicated before contrast-enhanced CT. AJR 2015 (jn press)


Adults:

  • 50mg Prednisone PO 13, 7 and 1 hour before the injection.
  • 50mg Benadryl (Diphenhydramine) IV/PO within 1 hour of the injection.

In an emergency setting an alternative faster (but less proven) regime is:

  • 200mg Hydrocortisone IV 4 hours before injection.
  • 50mg Benadryl (Diphenhydramine)IV/PO within 1 hour of the injection.

Pediatrics (For patients less than 50kg):

  • Prednisone 0.7 mg/kg (not to exceed 50mg) PO 13, 7 and 1 hour before the injection.
  • Benadryl (Diphenhydramine) 1mg/kg IV/PO (not to exceed 50mg) within 1 hour of the injection.

In an emergency setting an alternative faster (but less proven) regime is:

  • Hydrocortisone 1mg/kg (not to exceed 200mg) IV 4 hours before injection.
  • Benadryl (Diphenhydramine) 1 mg/kg IV/PO (not to exceed 50mg) within 1 hour of the injection.

Pre-Medication Regimen