Learning Center
New In Coagulation
Friday, May 2, 2008
ALLERGY TO HEPARIN
ALLERGY TO HEPARIN: FDA issued a Medwatch alert informing physicians and dialysis center staff about the safety issued related to heparin sulfate. As of February 2008, 350 adverse reactions have been reported including 4 deaths. A voluntary recall was issued by Baxter. It appears that an allergic reaction includes a minimum of 2 symptoms:
- Localized sensations of warmth
- Numbing or tingling of the extremities
- Difficulty swallowing
- Shortness of breath, wheezing or chest tightness
- Low BP
- Nausea or vomiting
The implicated lots appear to originate from China, in multi-vial dosing. It has been recommended to use heparin at the lowest possible dose and from other suppliers other than Baxter. Allergic reactions to heparin are quite rare, and this current cluster represents an outbreak most likely reflecting a manufacturing or storage process.
www.medscape.com/viewarticle/570227
Information as of 4/28/08
FDA scientists have identified a contaminant in the heparin - an oversulfated chondroitin sulfate. The contaminant mimics heparin activity so closely that it was not recognized by routine testing. FDA now has in vitro and animal data demonstrating a solid mechanistic link between the oversulfated chondroiton sulfate and the adverse events observed after bolus dosing. Our data demonstrate that the compound directly activates the kinin-kallikrein pathway in human plasma, which can lead to the generation of bradykinin (a potent vasoactive mediator) and C3a and C5a (potent anaphylatoxins). These data were recently published in the New England Journal of Medicine.
Several manufacturers and distributors of heparin products have initiated recalls of their products based on reports of adverse events associated with their product(s) or as a precaution after testing revealed that they were supplied with contaminated lots of heparin. Further information on these recalls may be found at
http://www.fda.gov/cder/drug/infopage/heparin/default.htm#recalls.
The contaminant found in heparin has now also been identified in some batches of the low-molecular-weight heparin enoxaparin (Lovenox/Clexane), the manufacturer, Sanofi-Aventis, has reported. But no increase in adverse reactions has been seen with the product.
The company told heartwire that it has put in place screening tests for the contaminant, oversulfated chondroitin sulfate, which has been detected "in very small concentrations" in a few batches. Australia, Sweden, and Italy--have requested the recall of the enoxaparin lots containing the contaminant. Other countries, including France, Belgium, and Spain, have advised that the product should be given only by subcutaneous injection, as the adverse reactions seen with contaminated heparin in the US and Germany have been associated with bolus intravenous use.
Donna Castellone
|
