The U.S. FDA has never inspected the Chinese manufacturing facility implicated in the Baxter heparin. Baxter suspended production of its blood-thinning drug heparin in multi-dose vials following the deaths of four patients in the U.S. and hundreds of reports of severe allergic reactions, including rapid drop in blood pressure, burning sensations, headaches, throat swelling and shortness of breath.

Baxter sources the drug's active pharmaceutical ingredient from an undisclosed U.S. supplier who operates a plant in China, and another one in the U.S. But the FDA has now revealed that the Chinese plant did not actually undergo a pre-approval inspection by the agency, as is required before a manufacturing facility is authorized to supply drug ingredients to the U.S.

The Chinese facility may or may not be behind the heparin adverse reactions. However, the situation highlights the concern in the U.S. over the mounting number of foreign-sourced drug ingredients and the FDA's questionable ability to effectively monitor quality control.