PRECLINICAL SAFETY ASSESSMENT OF CONTRAST-MEDIA - PREDICTIVE VALUE

The purpose of preclinical tests is to identify the potential benefits and risks of new diagnostic or therapeutic products. Regarding iodina ted contrast media (CM), LD50 tests were used extensively in the past. However, from both scientific and ethical perspectives, it is today h ighly relevant to question the use of LD50 tests. Due to species diffe rences and the very high volume of CM needed to kill half of the anima ls, such tests are not sensitive enough to differentiate between moder n nonionic CM. Further, they are not very predictive in terms of human tolerability. In other tests with more relevant end-points than death , overall tolerance to the new dimeric compound iodixanol (Visipaque), representing the latest step in the development of CM, has been shown to be higher than to the nonionic monomers. Clinical experience has s hown that the physiological parameters often stay closer to baseline a fter Visipaque than after administration of conventional CM.