Potential drug-drug interactions and radiodiagnostic procedures: an in-hospital survey.

OBJECTIVES: To evaluate the type, frequency, severity and predictors of potential Drug-Drug Interactions (DDIs) in a cohort of patients undergoing radiodiagnostic procedures. SETTING: Eight Radiology wards located in Tuscany (Italy). METHODS: All participants exposed to at least two medications were included in the analysis. DDIs were grouped according to their severity as 'minor', 'moderate' or 'major'. A logistic model was used to estimate Odds Ratios and 95\% Confidence Intervals for all predictors of potential DDI. MAIN OUTCOME MEASURES: Type and predictors of potential DDI in a cohort of patients undergoing radiodiagnostic procedures. RESULTS: One-thousand-and-two subjects (57.6\% females; mean age: 67.3 +/- 12.2) entered the analysis, and 46.1\% of them incurred in a potential DDI (78.9\% 'moderate' in severity). The combination of allopurinol and ACE-inhibitors was the most frequent (21/153) among major potential DDIs, while steroids were involved in all cases of potential DDI due to premedication. Co-morbidity, number of co-medications, advanced age and premedication use increased the risk of potential DDI; a protective role was found for positive history of allergy. When the analysis was restricted to subjects with premedication (n = 93), only 12.9\% of them reported a potential DDI directly attributable to premedication drugs. CONCLUSIONS: Among patients undergoing radiological examination, types and predictors of potential DDIs appeared in agreement with other kind of in-hospital populations. Premedication revealed to be a proxy predictor for potential DDIs. Considering the poor capability of the prescriber in recognizing interactions, their systematic evaluation (using an informatics tool) in patients undergoing radiological examination might be helpful in preventing the occurrence of clinically relevant DDIs.