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The U.S. Food and Drug Administration (FDA) has issued another alert over sterile products manufactured by Dallas-based NuVision Pharmacy. The repeat warning to healthcare providers follows NuVision's persistent refusal to recall products whose sterility is not guaranteed, the FDA said.

The first alert came on May 18, 2013, when the FDA advised healthcare professionals to immediately quarantine NuVision sterile products and refrain from administering them to patients. The most recent FDA letter sent to the company was dated July 26, 2013 and carried a request for the immediate withdrawal of all sterile product lots whose expiration date had not yet been reached. The FDA said in the letter that its investigators had observed poor sterile production practices at NuVision's factory in Dallas during an inspection conducted this April. As the agency noted, this raised concerns about the sterility of the products. Should a drug labeled sterile contain microbial contamination it could pose a serious risk to patients, potentially triggering life-threatening infections, the FDA wrote.

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NuVision's response to the letter was refusal to pull its sterile products off the shelves. Since the FDA does not have the authority to mandate such a move, it has deemed it necessary to warn healthcare providers once again to steer clear of NuVision's sterile products.

Following the April inspection, NuVision withdrew its methylcobalamin and lyophilized injections. The FDA was notified that some patients receiving the methylcobalamin injection had exhibited fever and flu-like symptoms and complained of soreness at the site of the injection. The agency said it had not received any adverse reports regarding other sterile products manufactured by NuVision.