WASHINGTON -- The government is ratcheting up testing of the blood thinner Heparin and its main ingredient, as new evidence pointed to China as the source of the tainted drug that killed as many as 21 Americans.
The Food and Drug Administration is now making sure that all supplies of Heparin and its key ingredient are tested for the mysterious contaminant, agency officials told reporters yesterday. Manufacturers and importers will have to conduct the sophisticated tests or government inspectors will do so before the products can be distributed in the United States.
"At our borders either we will be testing or we will be receiving results," said Dr. Janet Woodcock, who directs the FDA's drug division.
The agency announced the new steps as 20 of 28 samples taken from a suspect manufacturing plant in Changzhou, China, tested positive for the contaminant, Woodcock said.
That disclosure adds to suspicions that the contaminant was introduced during manufacture in China rather than during processing in the U.S., although FDA officials emphasized that their investigation is wide-ranging and continuing.
The contaminant mimics Heparin's key ingredient and evades detection by routine quality testing. Investigators are trying to determine whether the look-alike was added intentionally - and fraudulently - and whether it caused the more than 700 reports of serious side effects.
Woodcock said the twin mysteries should get answered soon, once scientists figure out exactly what the contaminant is. "When we understand it, it's really going to help us figure out how it got in there," she said, saying the agency is "very close to nailing this down."
After reports of Heparin-users experiencing plunging blood pressure, chest pains and dizziness, Baxter International Inc. recalled virtually all its Heparin products last month. Baxter scientists have ruled out common bacterial sources of contamination, such as the pertussis, botulinum, diphtheria, cholera and tetanus toxins, but that still leaves a range of natural and synthetic causes, a spokeswoman said.
Since the company's Feb. 28 recall, the FDA has received just two reports of side effects, neither fatal. "Doctors should reassure patients," Woodcock said.
The scare has spread globally, with authorities in Germany and Japan issuing recalls. Those countries are also testing Heparin products for the contaminant, FDA officials said.
Baxter bought the main Heparin ingredient from Scientific Protein Laboratories, a Wisconsin company that co-owned the Changzhou plant in eastern China. The Changzhou plant is no longer allowed to ship products to the U.S., Woodcock said, and FDA inspectors have been ordered to stop all other Heparin imports to make sure they have undergone the sophisticated testing for the contaminant.
Meanwhile, the five leading makers of Heparin and its key ingredient have committed to testing all of their supplies, said Steve Silverman, an FDA compliance official.
Critics have attacked the FDA for failing to inspect the Changzhou plant, as well as the farms, workshops and middlemen that supplied it with the pig intestines that are crushed and then purified to make the main Heparin ingredient. Critics say the FDA and industry need to do a better job policing the quality of drugs throughout their overseas supply chains.
In addition to visiting the Changzhou facility, the FDA has spoken with some of its suppliers and has discussed probing the rest of the supply chain with Chinese authorities, agency officials said.
"We are not simply relying on information from our Chinese counterparts," Silverman said. "We are engaged in an active investigation."
As part of its inspection of the Changzhou plant, Baxter confirmed that the facility assured the integrity of its suppliers, said Deborah Spak, a company spokeswoman. Baxter has sought to visit the Changzhou plant's suppliers, Spak said, "but we have not been able to get in there, and, quite honestly, that would be voluntary on their part. We are not their customer."