| Previous reaction to allergens only (eg shellfish, peanuts, medicine etc.) | MILD | MODERATE | SEVERE |
| Premedication | None | None | None |
| Previous reaction to same class of contrast agent going to be given (iodinated contrasts are all one class, gadolinium agents another class) | MILD | MODERATE | SEVERE |
| Premedication | None | Premedicate and use a different agent | Do not give contrast* |
| Previous reaction to different class of contrast agent than type to be given (iodinated contrasts are all one class, gadolinium agents another class) | MILD | MODERATE | SEVERE |
| Premedication | None | None | None |
*Unless benefits outweighs the risks, documentation needed
MILD REACTION: Nausea, vomiting, cough, warmth, headache, dizziness, shaking, altered taste, pallor, flushing, chills, sweating, nasal stuffiness, anxiety.
MODERATE REACTION: Rash, hives, iching, facial or eye swelling, tachycardia, bradycardia, hypertension, generalized or diffuse erythema, dyspnea, bronchospasm, wheezing, laryngeal edema, mild hypotension.
SEVERE REACTION: Convulsions, severe or rapidly progressing laryngeal edema, unresponsiveness, cardiopulmonary arrest, profound hypotension, clinically manifest arrhythmia.
Premedication for adults:
Lasser regimen: Mythylprednisolone, 32 mg orally given 12 hours and 2 hours before contrast injection.
Greenberger regimen: Prednisone 50 mg orally 13, 7 and 1 hour before contrast injection and Benadryl (Diphenhydramine) 50 mg IV/PO 1 hour before contrast injection.
Emergency regimen: Hydrocortisone 200 mg IV 4 hours before contrast injection and Benadryl (Diphenhydramine) 50mg IV/PO within 1 hour of the contrast injection.
Premedication for pediatrics (or patients less than 50 kg):
Routine regimen: Prednisone 0.7 mg/kg (not to exceed 50mg) PO 13, 7 and 1 hour before the injection or Prednisolone 0.7mg/kg (not to exceed 50mg) PO 13, 7 and 1 hour before the contrast injection. And Benadryl (Diphenhydramine) 1mg/kg IV/PO (not to exceed 50mg) within 1 hour of the contrast injection.
Emergency regimen: Hydrocortisone 1mg/kg (not to exceed 200mg) IV 4 hours before the contrast injection and Benadryl (Diphenhydramine) 1 mg/kg IV/PO (not to exceed 50mg) within 1 hour of the contrast injection.
Yale School of Medicine Premedication Policy