Search

Purpose: To evaluate the incidence and risk factors of late adverse reactions (ARs) to non-ionic low-osmolar contrast media (LOCM).Methods: The occurrence of late AR was monitored on day 1 and from day 7 to day 28 in all patients who received enhanced computed tomography using LOCM during a 5-week study period in a single tertiary hospital. Patients who experienced late AR were followed up for three years.Results: Among the total 10,540 LOCM exposures, 315 ARs (3.0%) were reported; acute ARs occurred in 108 LOCM exposures (1.0%) and late ARs occurred in 207 LOCM exposures (2.0%) (90.9% within one week, 9.1% developed afterwards by day 20). Previous history of drug allergy (odds ratio [OR] = 4.59; 95% confidence interval [CI] 2.17-9.71) and allergic diseases (OR = 2.54; 95% CI 1.32-4.91) were risk factors of late ARs to LOCM. Although the recurrence rate was lowered with premedication from 8.5% to 1.7% (8/94 vs. 3/178; p = 0.016), LOCM change did not make difference compared to reuse of the culprit LOCM (2/38 vs. 9/234; p = 0.655). In patients with a history of late AR to LOCM, the risk of recurrent reactions decreased with longer time intervals between exposures (OR = 0.86; 95% CI: 0.77-0.97; p = 0.025) and with the use of antihistamine premedication (OR = 0.27; 95% CI: 0.06-0.99; p = 0.049).Conclusions: Late ARs to LOCM occurred mostly within one week. The use of premedication may be helpful in reducing the recurrence of late ARs. [ABSTRACT FROM AUTHOR]

Abstract: Background: Radio-contrast media (CM)-related adverse reactions are important clinical problems that may cause fatal anaphylaxis. Accordingly, it has been common practice to premedicate patients who have had previous reactions to CM with corticosteroids, antihistamines, and H2 blockers to prevent hypersensitive reactions. However, the effectiveness of premedication has not been properly demonstrated, especially in cases related to non-ionic CM. In this study, we evaluated the effectiveness of premedication at preventing of non-ionic CM immediate-type hypersensitivity reactions. Methods: A total of 30 patients who had been pretreated with corticosteroid and H1 antihistamines and/or H2 blockers in a 3-year period were enrolled. The results of premedication were evaluated in terms of clinical characteristics and the features of breakthrough reactions. Results: Hypersensitivity reactions were not prevented in 5 of the 30 patients who had experienced prior CM reactions (overall recurrence rate after premedication 16.7%; 4/17 patients with mild previous reactions, and 1/13 patients with severe previous reactions). The recurrence rate after premedication was significantly higher in patients with mild previous reactions than in those with severe reactions (23.5% vs. 7.7%; p <0.001). The breakthrough reactions were similar to the prior reactions in terms of severity and clinical manifestations. Conclusion: Premedication with corticosteroid and H1 antihistamines and/or H2 blockers effectively prevent non-ionic CM-related adverse events in most patients who have had severe previous reactions to CM. However, physicians should be aware of the possibility of premedication failing and of breakthrough reactions, even in cases in which the previous reactions were mild. [Copyright &y& Elsevier]