N-Acetyl Cysteine Prevents Kidney Damage from Coronary Procedure

Taking supplemental N-acetyl cysteine (NAC), may help prevent kidney damage sometimes caused by a procedure conducted to determine whether a heart’s blood vessels are blocked, according to a new study in the Journal of the American Medical Association (2003;289:553–8). In addition to preventing kidney impairment from the procedure (coronary angiography), taking NAC may reduce the length of hospitalization afterward. Up to 15% of people undergoing coronary angiography may experience kidney damage from the contrast dye.

Two hundred Chinese adults between 48 and 82 years old with moderately impaired kidney function and scheduled to undergo coronary angiography participated in the study. They were randomly assigned to receive either 600 mg of oral NAC twice a day on the day before and the day of the procedure or a similar looking placebo. Blood levels of creatinine (used to evaluate kidney function, where higher levels suggest more kidney impairment) were measured initially and then after 24 hours, 48 hours, and seven days following the procedure. All participants received the same type and amount of contrast dye during the procedure.

Only 4% of those taking NAC, compared with 12% of those taking the placebo, experienced a 25% increase in blood creatinine within 48 hours of receiving the contrast dye. A small, but statistically significant, decrease in the length of hospitalization was also observed in those taking NAC, compared with those taking the placebo.

Individuals with impaired kidney function or diabetes are at greatest risk of having kidney impairment following the procedure. In some cases, the damage to the kidneys is long-lasting or permanent, and may in some cases result in the need for dialysis to help detoxify the blood. No other conventional treatments have been shown to prevent contrast dye-induced kidney impairment. Routine implementation of NAC therapy may lead to fewer complications after angiography and reduced healthcare costs associated with the procedure.

Little is known about how NAC prevents kidney damage. Some studies suggest it may act as an antioxidant and protect the kidney against oxidative damage caused by the contrast dye, while other studies suggest NAC increases circulation in the kidneys and improves their ability to filter the blood. More research is needed to clarify this issue. While short-term use of NAC is safe, studies show that taking it long-term may increase the need for zinc and copper. Some physicians recommend taking 30 mg of zinc and 2 mg of copper per day when taking NAC for prolonged periods.

Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice at New England Family Health Associates located in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.

Copyright © 2003 Healthnotes, Inc. All rights reserved. Republication or redistribution of the Healthnotes® content is expressly prohibited without the prior written consent of Healthnotes, Inc. Healthnotes Newswire is for educational or informational purposes only, and is not intended to diagnose or provide treatment for any condition. If you have any concerns about your own health, you should always consult with a healthcare professional. Healthnotes, Inc. shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Healthnotes and the Healthnotes logo are registered trademarks of Healthnotes, Inc.