INCIDENCE OF ROENTGEN CONTRAST-MEDIUM REACTIONS AFTER INTRAVENOUS-INJECTION IN PRE-REGISTRATION TRIALS AND POSTMARKETING SURVEILLANCES

The relative risk of adverse drug reactions of ionic versus non-ionic contrast media injected i.v. were compared for different types of tria ls using odds-ratio. The absolute and relative risk found in large pos t-marketing trials were compared with that found in the iohexol pre-re gistration trials. The absolute risks were 2 to 10 times higher in the pre-registration trials compared to the post-marketing surveillances. The relative risk for all adverse drug reactions was 3 to 6 times hig her for ionic vs. non-ionic media and independent of pre- or post-regi stration studies. The odds-ratio seems to be a feasible method of comp aring the relative risk of adverse reactions in various trials.