The evidence is strongest for N-acetylcysteine.
In studies of interventions to prevent contrast-induced nephropathy, results have been heterogeneous. Investigators performed a systematic review and meta-analysis of 41 randomized trials (that included 6379 patients) of medications to prevent nephropathy (defined as increase in serum creatinine of >0.5 mg/dL or >25% at 48 hours) after injection of iodinated contrast media. Studies addressed N-acetylcysteine, theophylline, aminophylline, fenoldopam, dopamine, iloprost, furosemide, bicarbonate, ascorbic acid, mannitol, and a statin. In most trials, enrolled patients had impaired renal function (serum creatinine >1.2 to 1.5 mg/dL), and, in all but one, the evaluated procedure was cardiac catheterization.
N-acetylcysteine, compared with saline alone (26 studies), significantly lowered risk for nephropathy (relative risk, 0.62). Theophylline (6 studies) did not lower risk significantly, although the relative risk was 0.49. Dopamine and fenoldopam (2 studies each) were not effective, and furosemide (2 studies) increased risk for nephropathy.
Comment: This meta-analysis helps us interpret the results of the many small studies in which the effect of N-acetylcysteine was evaluated. N-acetylcysteine prevents nephropathy in patients with renal insufficiency who receive contrast agents for cardiac catheterization. Using N-acetylcysteine in these patients, and in others with renal impairment who receive similar doses of contrast media, makes sense.
— Richard Saitz, MD, MPH, FACP, FASAM
Published in Journal Watch General Medicine March 27, 2008
Kelly AM et al. Meta-analysis: Effectiveness of drugs for preventing contrast-induced nephropathy. Ann Intern Med 2008 Feb 19; 148:284.