UPDATE 2-New warnings added to agents used in MRI tests

* Contrast agents seen unsafe for kidney disease patients

* FDA says can lead to rare, possibly fatal condition

* Bayer, Covidien, GE Healthcare products cited (Adds GE Healthcare statement)

NEW YORK, Sept 9 (Reuters) - New warnings of a potentially fatal skin disease will be added to labels for imaging drugs sold by Bayer BAYGn.DE, Covidien COV.N and GE Healthcare cautioning against their use by patients with kidney disease, the U.S. Food and Drug Administration said on Thursday.

The gadolinium-based contrast agents (GBCAs), which are intravenous drugs used to help make diagnostic tests such as MRI scans or angiography easier to read, can cause a rare and potentially fatal condition known as nephrogenic systemic fibrosis in kidney disease patients, the FDA said.

“The FDA is requiring these labeling changes to enhance the safe use of gadolinium-based contrast agents, including avoidance of certain agents among patients at highest risk for nephrogenic systemic fibrosis,” Rafel Rieves, director of the Division of Medical Imaging Products in the FDA’s Center for Drug Evaluation and Research, said in a statement.

The warnings will be added to Bayer's Magnevist, Covidien's Optimark, and Omniscan, made by General Electric's GE.N healthcare division, the agency said.

The warnings will say the products are inappropriate for use among patients with acute kidney injury or chronic severe kidney disease. All GBCA labels will emphasize the need to screen patients to detect these types of kidney dysfunction before administration, the agency said.

GE Healthcare said it will update the Omniscan label to be consistent with the FDA’s guidance.

“Omniscan has been used for more than 17 years in more than 48 million doses to detect a variety of life-threatening conditions. GBCAs continue to be a valuable diagnostic tool with a proven safety record for the overwhelming majority of patients to whom they are prescribed,” GE Healthcare spokeswoman Aleisia Gibson said in a statement.

Nephrogenic systemic fibrosis (NSF) causes formation of excess fibrous tissue in the skin, joints, eyes and internal organs. It can lead to death if internal organs become affected.

The FDA said it will continue to assess the safety of each GBCA to better estimate its NSF risks. (Reporting by Bill Berkrot and Lisa Richwine; editing by John Wallace)