Incidence rate of severe adverse drug reactions to nonionic contrast media at the National Hospital Organization Osaka National Hospital

Summary Background Severe adverse drug reactions in response to intravascular contrast media used in computed tomography, although rare, are potentially life-threatening. This retrospective cohort study aimed to estimate the incidence rate of severe adverse drug reactions to nonionic contrast media at the National Hospital Organization Osaka National Hospital and to report individually on each fatality. Methods In total, 42,501 relevant cases were obtained from the individual case safe reports of the Ministry of Health, Labour and Welfare and the reports of code blue from our hospital database for the period of January 2013 to December 2017. The cases were studied, and the rate of adverse drug reactions was calculated from these data. Results Severe adverse drug reactions occurred in 0.019% (8/42,501) of the patients, including two deaths. All eight of these patients presented with disturbance of consciousness. Additionally, one patient had dyspnea, five had distributive shock that recovered after treatment, and two died. However, a causal relationship to the contrast media could not be established in one death. When examining the medical histories, four patients were found to have renal dysfunction. Discussion Although the rate of severe adverse drug reactions in this study appears to be higher than expected, the sample size of 42,501 patients is insufficient to conclusively determine the incidence and mortality rates of adverse drug reactions, as these rates are extremely low. Further studies are required to estimate the countrywide prevalence of adverse drug reactions in response to contrast media.