"If a person's kidneys aren't effectively clearing heparin from the blood, the drug stays active in the body for longer than expected," said Nigel Key, a hematologist with UNC Health Care and the UNC School of Medicine and one of the paper's coauthors. "That can represent a potentially dangerous situation for the physician, pharmacist and patient."
Heparin prevents blood clots from forming and is most often used during and after such procedures as kidney dialysis, heart bypass surgery, stent implantation, indwelling catheters and knee and hip replacement. Its side effects can include uncontrolled bleeding and thrombocytopenia (too few platelets in the blood). The worldwide sales of heparin are estimated at $4 billion annually.
The natural form of the drug was in the spotlight in spring 2008 when more than eighty people died and hundreds of others suffered adverse reactions to it, leading to recalls of heparin in countries around the world. Authorities linked the problems to a contaminant in raw natural heparin from China. Natural heparin is most commonly extracted from the linings of pig intestines.
"The pig stuff has served us well for fifty years and is very inexpensive, but if we cannot control the supply chain, we cannot ensure the safety of the drug," Liu said. "I am working for the day when synthetic heparin can be brewed in large laboratories at a low cost."
|Contact: Thania Benios|
University of North Carolina at Chapel Hill