(Reuters) -The U.S. Food and Drug Administration on Tuesday warned eight companies, including pharmacy giants CVS Health Corp (NYSE:CVS) and Walgreens Boots Alliance (NASDAQ:WBA), against manufacturing or marketing unapproved eye products.
The eye products addressed in the FDA's letters to these companies are illegally marketed to treat conditions like conjunctivitis, cataract and glaucoma, the agency said, adding that such drugs pose an increased risk to users as they can bypass some of the body's natural defenses.
Some of the these eye products were labeled to contain silver, the FDA said, adding that long-term use of drugs containing silver can cause some areas of the skin and other body tissues, including in the eye, to permanently turn gray or blue-gray.
CVS and Walgreens said they have stopped the sale of the unapproved eye drops, and that customers who purchased these products could return them for a full refund.
Among the companies, the FDA also pulled up Similasan, asking the privately held Swiss drugmaker to meet relevant safety limits for levels of diethylene glycol or ethylene glycol, two common contaminants in some medicine, as they could lead to lethal poisoning at higher levels.
Similasan did not immediately respond to Reuters' request for comment.
The U.S. health regulator has asked the companies to respond within 15 days of receipt of the letters and state how they will correct the violations.
The FDA warned that failure to correct the violations may result in legal action, including product seizure and court orders requiring the companies to stop manufacturing and distributing an unapproved product.