Nephrotoxic Polypharmacy and Risk of Contrast Medium-Induced Nephropathy in Hospitalized Patients Undergoing...

For unknown reasons, there is discordance among previous reports with regard to the association of contrast medium (CM) with nephropathy and the incidence of nephropathy after contrast-enhanced CT. This study aimed to determine the frequency of and possible factors related to CM-induced nephropathy in hospitalized patients, with an emphasis on detailing coprescriptions with nephrotoxic potential.

Of 1378 inpatients who underwent CT, 208 (15.1%) met the inclusion criteria: receipt of IV iodinated CM and baseline serum creatinine level obtained within 45 days before and within 2 weeks after CT. Patient demographics, clinical characteristics, comorbidity, nephrotoxic comedications (nine classes of drugs), and type of CM administered were retrospectively reviewed. Relationships between CM-induced nephropathy (serum creatinine level increase ≥ 25% or ≥ 0.5 mg/dL after CT) and risk factors were assessed by stepwise multivariate logistic regression.

The cohort of 208 subjects had a high number of comorbidities (mean [± SD], 5.8 ± 3.5 diagnoses) and a high rate of receiving nephrotoxic comedications (45.2%). CM-induced nephropathy was detected in 27 (13.0%) patients. Concurrent use of four nephrotoxic agents (odds ratio [OR], 26.250; 95% CI, 3.673-233.993) was the most influential factor associated with CM-induced nephropathy; other predictors included preexisting renal disease (OR, 8.218; 95% CI, 1.622-42.357), baseline serum creatinine level less than 0.7 or greater than or equal to 1.3 mg/dL (OR, 3.463; 95% CI, 1.341-9.025), and hemoglobin level less than 9.3 g/dL (OR, 3.141; 95% CI, 1.087-8.946).

Among the known risk factors, such as preexisting renal disease, high serum creatinine level, and low hemoglobin level, a statistically significant association was identified between CM-induced nephropathy and concurrent receipt of four nephrotoxic medications. Relevant preventive measures are warranted for individuals at risk, especially hospitalized patients receiving multiple nephrotoxic medications who require contrast-enhanced CT.