UK drug giant, GlaxoSmithKline, was hit on Friday after the US Food and Drug Administration and Department of Justice seized batches of the company’s diabetes treatment, Avandamet (rosiglitazone/metformin), and its anti-depressant, Paxil CR (paroxetine controlled-release), saying they failed to meet the agency’s standards.

The FDA and the DoJ said that the move came in response to ongoing concerns about manufacturing quality, noting that the two drugs’ manufacturing practices “failed to meet the standards laid out by [the] FDA that ensure product safety, strength, quality and purity.” During a site inspection, the agency said that it found that the Paxil CR tablets could split apart, with patients potentially receiving a portion of tablet lacking any active ingredient, or a portion containing active ingredient but without the intended controlled-release effect. Additionally, the FDA found some Avandamet tablets with an inaccurate dose of the active ingredient.

The federal authorities said they were forced to intervene as a result of GSK’s failure to recall all affected lots of the products after warrants were issued by district courts in Puerto Rico and Tennessee. “[The FDA and DoJ] will not allow drug manufacturers to ignore our high public health standards for drug manufacturing,” said John Taylor, the FDA’s associate commissioner for regulatory affairs. “Once we discover a company is not following the standards, which were created to ensure safety and quality, we expect them to correct the deficiencies in an expedited manner,” he added.

The agency, which said it does not believe that the products pose a significant health risk, has urged patients to continue using the drugs, but talk with their doctor about possible alternatives for use until the manufacturing problems have been corrected. In Europe, the regulator said it was aware of the problems and was planning a potential inspection of GSK’s Puerto Rico site. The products will remain on the European market for the time being, as the company says that none of the seized lots had been supplied to the continent. However, the EMEA says that the allegations are serious, and raise serious compliance issues, and it will continue to monitor the situation and its implications for patients in Europe.

In a statement, GSK said that it was working with the FDA to resolve these issues as quickly as possible. The company’s share price dropped by as much as 5% on the London Stock Exchange on Friday afternoon on the news, and continued to sink during morning trading today. The news also had negative repercussions for UK biotechnology company, SkyePharma, which provided the controlled-release formulation, also saw its share price sink by some 16% on the LSE on Friday.