Safe use of radiographic contrast media

Injection of iodinated radiographic contrast media is generally safe, however with increased use adverse events are more likely to occur. The most important adverse effects include hypersensitivity reactions, contrast-induced nephropathy and thyrotoxicosis. There is no protocol that will prevent non-IgE-mediated anaphylaxis. In patients with moderate renal dysfunction, adequate hydration and use of as little contrast media as practical is recommended. Contrast-induced nephropathy is often transient. Metformin has been associated with lactic acidosis in patients receiving contrast media. It should therefore be discontinued for 48 hours starting on the day of the contrast study. The use of alternative non-iodinated contrast agents, particularly in ultrasound and magnetic resonance, is also growing. Gadolinium magnetic resonance agents have been associated with nephrogenic fibrosing sclerosis in patients with renal dysfunction.