Millions of people receive contrast agent each year, including most heart patients who have angioplasties and stents, as well as those having a CT scan. Contrast agent helps physicians see the things we need to see, but it also does pose a hazard to some people, says Kelly. This drug, which is quick, convenient, inexpensive and widely available, with no major side effects, appears to be the best choice to protect those whose kidneys are most at risk.
Only studies that involved intravenous iodine-containing contrast agents, and compared a drug with a water or saline control, were included in the analysis. Oral milkshake barium contrast agents, used in CT scans of the digestive system, do not cause kidney damage, and were not included.
The study also did not assess potential ways to protect against kidney damage from gadolinium contrast agents used in MRI (magnetic resonance imaging) scans. Since May 2007, those contrast agents have carried a warning from the U.S. Food and Drug Administration about risk to kidneys.
Kelly, Carlos and their colleagues performed the study to try to get a firm answer to a question that has puzzle medical imaging specialists for years.
Although many drugs have been tried for prevention of iodine-related contrast-induced nephropathy, contradictory evidence has emerged from studies of how well they work. The result has been widespread variation in what hospitals and medical imaging centers do before scanning a patient.
Although a prospective trial comparing N-acetylcysteine directly to other drugs should be conducted to verify the U-M teams findings, the team hopes its new study will help guide both clinicians and patients.
In fact, Kelly says, patients who know they have weakened kidneys also called impaired renal function should speak up when their d
|Contact: Kara Gavin|
University of Michigan Health System