Post-marketing surveillance of the safety profile of iodixanol in the outpatient CT setting: a prospective, multicenter, observational study of patient risk factors, adverse reactions and preventive measures in 9953 patients.

Purpose: Non-interventional study in outpatient, contrast-enhanced CT; 1. to determine the extent of preventive measures for risk reduction of adverse drug reactions after contrast-enhanced CT examinations. 2. to prospectively determine the incidence and severity of adverse drug reactions occurring after administration of the iso-osmolar contrast medium iodixanol. 3. to determine a possible influence of preventive measures on the incidence/severity of adverse drug reactions..

Materials And Methods: Evaluable documentation was provided for 9953 patients from 66 radiology centers across Germany. Patient characteristics, aspects of iodixanol administration, and adverse events with an at least "possible" relationship were documented on a standardized case report form (CRF) and were evaluated up to seven days after contrast medium administration.

Results: About 55.5 % of patients showed one or more risk factors (e. g. impaired renal function 4.4 %, diabetes mellitus 8.5 %, hypertension 20.6 %). One third of the sites did not implement any preventive measures. Patients with a known risk for an allergy-like reaction were more likely to receive pharmacologic preventive treatment (0.5 - 50.5 %). Oral hydration was the main preventive measure in patients with renal risk factors (< 8 %) followed by intravenous hydration (1 %). Adverse drug reactions, mainly hypersensitivity reactions, occurred in 77 patients (0.74 %), but were classified as serious in only 3 patients (0.03 %). No statistically significant correlation between risk factors, preventive measures, and adverse reactions could be found.

Conclusion: The use of preventive measures for CT examinations in this outpatient setting was generally low with risk patients being pre-medicated more often, depending on their history. In the routine outpatient setting, iso-osmolar iodixanol was very well tolerated in almost 10,000 patients undergoing diagnostic CT. The rate of acute and delayed adverse reactions was low. No correlation could be found between risk factors, preventive measures and the incidence of adverse drug reactions.

Key Points: • Rare use of preventive measures for outpatient CT examinations.• Low rate of acute and late adverse drug reactions to iodixanol.• No correlation between risk factors, preventive measures and adverse drug reactions.