What is the recommended frequency for steroid pre-dosing in patients with a known contrast (intravenous contrast media) allergy?

From the Guidelines

For patients with a known contrast allergy, a regimen of 50 mg of prednisone administered 13 hours, 7 hours, and 1 hour before the procedure, along with 50 mg of diphenhydramine 1 hour before the procedure, is recommended to reduce the risk of recurrent anaphylactoid reaction. This recommendation is based on the findings of the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention 1. The guideline suggests that adequate pretreatment of patients with prior anaphylactoid reactions reduces the recurrence rate to close to zero.

Key Points

• The incidence of anaphylactoid reactions to contrast media is 1%, and the incidence of severe reactions may be as low as 0.04% 1.
• A history of prior anaphylactoid reaction increases the recurrence rate without prophylaxis to 16% to 44% 1.
• The use of steroids, such as prednisone, and diphenhydramine has been shown to reduce the risk of recurrent anaphylactoid reaction 1.
• In practice, a regimen of 60 mg of prednisone the night before and morning of the procedure, along with 50 mg of diphenhydramine 1 hour before the procedure, is often used 1.

Considerations

• Patients with a history of seafood or shellfish allergies are not at increased risk for an anaphylactoid reaction from exposure to contrast media, and pretreatment with steroids is not recommended in these cases 1.
• The recommended regimen may need to be adjusted in emergency situations where the full 13-hour protocol is not possible 1.

From the Research

Steroid Pre-Dosing Frequency for Contrast Allergy

• The frequency of steroid pre-dosing for patients with a known contrast allergy is typically administered in a two-dose regimen, with the first dose given 12 hours before and the second dose given 2 hours before the contrast media injection 2, 3.
• This two-dose regimen has been shown to significantly reduce the incidence of reactions to intravenous contrast material, except for a category of reactions dominated by hives 3.
• The use of a 13-hour corticosteroid and diphenhydramine premedication regimen has also been studied, with a breakthrough reaction rate of 1.2% reported in patients receiving this regimen before undergoing CT with IV iodinated low-osmolality contrast material 4.
• However, the effectiveness of steroid premedication in preventing repeat allergic-like reactions is still a topic of debate, with some studies suggesting that using a different iodinated contrast material may be more effective than steroid premedication alone 5.
• The optimal frequency and dosage of steroid pre-dosing may vary depending on the individual patient's medical history and the specific contrast media being used, and further research is needed to determine the most effective premedication regimen 2, 5, 3, 4, 6.

Key Findings

• A two-dose corticosteroid regimen can significantly reduce the incidence of reactions to intravenous contrast material 2, 3.
• The use of a 13-hour corticosteroid and diphenhydramine premedication regimen can reduce the breakthrough reaction rate in patients receiving IV iodinated low-osmolality contrast material 4.
• Steroid premedication may not be as effective in preventing repeat allergic-like reactions as using a different iodinated contrast material 5.
• Allergic-like reactions to gadolinium-containing contrast media can occur despite premedication with corticosteroids and antihistamines 6.