Wednesday, April 30, 2008

Hematology - heparin contaminant may have been deliberate

A US Congressional hearing was held on Tuesday to discuss the recent heparin contamination issue. The hearing was dubbed, "The Heparin Disaster: Chinese Counterfeits and American Failures".

Baxter, which supplied half of the US market, issued a voluntary recall of the drug in January 2008 and again in February after multiple patients starting experiencing severe side effects like abdominal pain, decreased blood pressure, burning sensation, chest pain, diarrhea, dizziness, loss of consciousness and vomiting. The drug eventually caused more than 80 deaths.

The company denied that it was responsible for contaminated batches of Heparin, an anticoagulant used mostly in hospitals, and that it may have been a deliberate contamination. It's CEO, Robert Parkinson, said that, CEO Parkinson said, "We're alarmed that one of our products was used, in what appears to have been a deliberate scheme, to adulterate a life-saving medication, and that people have suffered as a result".

The contaminant was an altered form of chondroitin sulfate, a drug that mimics the affects of Heparin. The company said during the hearing that the drug was in the batches before it reached Baxter's supplier, Scientific Protein Laboratories. Several other companies in multiple other countries found traces of the contaminant in their supplies of Heparin, as well. Parkinson testified that the company is still trying to understand where in the supply chain the contaminant was introduced, but the company believes it was in the raw material.

Heparin is one of several products coming out of China that have been recalled because of problems with production. Last year, there were recalls concerning toys and toothpaste made in China. The Chinese government has maintained that the contaminated Heparin was not associated with the adverse affects and deaths. This theory was debunked by Kishimoto et al., who provided a scientific rationale for a potential biologic link between the presence of over-sulphated condroitin in suspect lots of heparin and the observed clinical adverse events. They reported their findings in the NEJM earlier this year.

Heparin is a generic that has been around for more than 70 years. It is made from pig intestines. At the hearing, members of Congress discussed the rising cost of hogs as a potential reason for someone substituting the Heparin with the lower-cost chondroitin sulfate. The contaminant is an unnatural substance that was highly processed, pointing to the likelihood that the substance was deliberately added.

The committee appeared to be laying blame with the US FDA inspectors; the FDA only inspects foreign drug makers every 13 years. Baxter relied on inspections and audits of the SLP factory done by its predecessor, Wyeth, and did not conduct audits of the Chinese factory itself.

In short, it was a disaster waiting to happen; no one took responsibility or accountablity for the quality of either the raw materials or the final product, ultimately compromising patient safety.

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