Update on New Zealand contaminated Heparin

Update on New Zealand contaminated Heparin

23 July 2008

Please attribute to Stewart Jessamine, Group Manager, Medsafe

Medsafe and the Ministry of Health are continuing to monitor the situation with respect to the global problem of heparin contaminated with over-sulphated chondroitin sulphate (OSCS) entering the market.  Medicines regulators around the world have taken a number of different approaches to managing this issue.  In New Zealand, Medsafe requires all manufacturers of heparin-based products to test for the presence of OSCS in products supplied to the market. To date all of the manufacturers of heparin and low molecular weight heparin products supplied to New Zealand have reported that OSCS has not been detected in the products used by patients.

In response to reports that some batches of Clexane that have tested negative for OSCS have been made using heparin that contained a low level of OSCS, Medsafe and its expert advisory committee reassessed the safety of these batches and concluded that they could continue to be distributed in New Zealand. In addition, Medsafe has further tightened its controls on manufacturers by requiring that all ingredients used in the manufacture of heparin and low-molecular weight heparin must be negative for OSCS.

Medsafe's investigation has identified only one medical device that is used in direct contact with patients which has utilised heparin containing OSCS as a coating. The suppliers of this device which is used in cardiac surgery have already issued advice to specialists using the device advising that alternative products should be used if possible.   Uncontaminated supplies of the device are not expected to be available for another two months.

While there has been no increase in reporting of adverse reactions to heparin or low molecular weight heparins in New Zealand since the issue of OSCS contamination was first identified, Medsafe is advising medical professionals and DHBs, that even with the current testing systems it cannot assure that very low levels of OSCS are not present in some products.  Medsafe continues to encourage healthcare practitioners to be on the look out for possible adverse reactions to heparin containing products and to report them to the New Zealand Pharmacovigilance Centre at the University of Otago.

Background
Key points:

·        Detectable levels of over-sulphated chondroitin sulphate (OSCS) have not been found in medicines containing heparin or low molecular weight heparins supplied in New Zealand.

·        Because of the limitations of the available test methods, the presence of low levels of OSCS in products cannot be completely excluded.

·        There has been no increase in adverse reaction reports in New Zealand for medicines containing heparin or low molecular weight heparins.

·        Two types of medical device have been found to contain heparin contaminated with OSCS. These are:

o        an oxygenator used in cardiac surgery, where alternative products should be used if possible

o        blood collection containers, where use of the products has been allowed where OSCS levels are below 6%.

·        Healthcare practitioners are asked to be alert for, and to promptly report, any adverse reactions occurring in patients exposed to medicines or medical devices containing heparin or low molecular weight heparins.

General
Early this year the United States Food and Drug Administration (FDA) advised of serious adverse reactions in the USA associated with the intravenous use of certain brands of heparin injections. Further investigation identified that a contaminant, over-sulphated chondroitin sulphate (OSCS), was responsible for these adverse reactions.

The reactions were severe in some cases and were typically immunoallergic in nature (anaphylactic type reactions).  By mid-April 2008, approximately 81 deaths had been reported as associated with intravenous heparin containing high levels of OSCS.

As a result of the FDA reports, Medsafe immediately conducted a review of products available in New Zealand and issued advice to key stakeholders. Investigation of the problem has been ongoing.

Medicines
All medicines containing heparin or low molecular weight heparins This includes batches of Clexane recalled in Australia where samples of the heparin used in the manufacture of some batches of enoxaparin (the active ingredient in Clexane) were found to contain OSCS. Testing of the enoxaparin in these batches for OSCS was negative. supplied in New Zealand have been tested. In all cases, OSCS has been reported as ‘not detected’.  The limitations of the test method mean that OSCS levels below 1% will not be detected. Consequently, the presence of a low level of OSCS in products supplied in New Zealand cannot be completely excluded
An analysis conducted by Medsafe, and endorsed by its expert advisory group, supports the conclusions of medicines regulators in Europe and the United States that it is safe to use products where OSCS has not been detected.  International data demonstrate that there has been no increase in adverse reactions reported worldwide for heparin or low molecular weight heparin-containing medicines in which the presence of OSCS was ‘not detected’. This is supported by New Zealand data which confirm there has been no increase in the reporting of adverse reactions to heparin or low molecular weight heparins in New Zealand in 2008.

Medical devices

Information so far indicates that only one medical device used in direct patient contact that utilises heparin contaminated with OSCS has been supplied in New Zealand. Users of this device, the Medtronic Trillium Oxygenator (used in cardiac surgery), have been informed of the need to use this device with caution and only where an alternative product is unavailable. Medtronic advises that it will be approximately two monthsbefore uncontaminated stock of the Trillium Oxygenator will be available.

Some blood sample containers have also been found to contain heparin contaminated with OSCS. Medsafe is satisfied that the presence of OSCS at levels less than 6% will not affect blood test results. Laboratories and other organisations using these products have been advised to be alert to the possibility of unusual test results when these tubes are used and to re-test if necessary.

Reporting of adverse reactions

Health practitioners should remain alert to the possibility of adverse events and should promptly report any adverse reactions appearing to be associated with medicines or medical devices containing heparin or low molecular weight heparin.

·        Reports of adverse reactions to medicines should be sent  to the New Zealand Pharmacovigilance Centre / Centre for Adverse Reactions Monitoring (CARM):
                http://www.medsafe.govt.nz/profs/adverse/reactions.asp

·        Reports relating to medical devices should be made using the Medical Device Incident Reporting Form which can be found at:
        http://www.medsafe.govt.nz/downloads/device.doc

ENDS