As a healthcare professional it is most likely that you have administered heparin many times to many patients over the course of your career, without careful consideration of the risks of anticoagulation therapy. Heparin administration has almost become a routine procedure today, especially for those working in surgical settings. However, Heparin is a potent drug that can have lethal consequences if administered incorrectly.  Did you know that thirty-four sentinel events related to anticoagulation were reported to the Joint Commission between 1997 and 2007? Twenty-six resulted in death; six resulted in loss of function. The most frequent causes were cited as inaccurate or incomplete monitoring, wrong dose, and pump malfunction or error (Joint Commission, 2008).

As a resurgence of patient safety awareness continues in the U.S., Medwatch, a division of the US Food and Drug Administration (FDA) recently announced a change in heparin dosage, effective October 1, 2009 . This change includes a new reference standard to determine the potency of the drug and improved ability to detect impurities that may be present in heparin. This change will synchronize the USP unit dose with the World Health Organization (WHO) International Standard unit dose. These changes will result in approximately a 10% reduction in the potency of the heparin marketed in the United States.

This may have clinical significance in some situations, such as when heparin is administered as a bolus intravenous dose, where an immediate anticoagulant effect is clinically important. Healthcare providers should be aware of the decrease in heparin potency as they monitor the anticoagulant effect of the drug; as more heparin may be required to achieve and maintain the desired level of anticoagulation in some patients.

There will be simultaneous availability of heparin manufactured to meet the “old” and “new” USP monograph, with potential differences in potency. Products using the new “USP unit” potency definition are anticipated to be available on or after October 8. The FDA is working with the manufacturers of heparin to ensure that an appropriate identifier is placed on heparin made under the new USP monograph. Most manufacturers will place an “N” next to the lot number. FDA is also working with the heparin manufacturers to study the impact of this variation in potency and will make the results available when the studies have concluded.

To stay informed, visit:  MedWatch Safety Alerts for Human Medical Products. MedWatch alerts provide timely new safety information on human drugs, medical devices, vaccines and other biologics, dietary supplements, and cosmetics. The alerts contain actionable information that may impact both treatment and diagnostic choices for healthcare professionals and patients.