[Prevention of intolerance to iodized contrast media ]

The exact mechanisms of adverse reactions to contrast media are still imperfectly known. However, these reactions may be classified as idiosyncratic. Non-idiosyncratic reactions can be prevented by using new, non-ionic contrast agents. Idiosyncratic reactions can be prevented by specific premedication. Patients with a history of idiosyncratic reaction may benefit from corticosteroids and antihistamines administered prophylactically. Patients who seem to be more likely than others to react to contrast media must be premedicated, the risk of reaction being identified and evaluated by questioning. It has recently been suggested that all patients about to receive an intravascular injection of contrast medium should also be premedicated.