Nephrotoxic effects of X-ray contrast media

The annual sale of x-ray contrast media (CM) now represents 60 million doses, and contrast nephropathy (CN) has been the third-leading cause of hospital-acquired acute renal failure. In this review article, physicochemical, pharmacokinetic, and pharmacodynamic properties of CM are surveyed. The definition of CN is presented, as well as the mechanisms involved in the pathogenesis. Low osmolar monomeric CM (LOCM) are less nephrotoxic than the older ionic high osmolar CM (HOCM), but in risk patients the incidence of CN is still high after intravascular administration of LOCM. Non-ionic dimeric CM are iso-osmolar to plasma (IOCM), and they have reduced the nephrotoxicity even more than LOCM. The most important risk factors for CN are diabetes mellitus and impaired renal function. Selection of patients, hydration, and type of CM are essential for prevention and prophylaxis of CN. We do not recommend routine prophylaxis with N-acetylcysteine (NAC) during CM investigations, but its use in high-risk patients should be considered.