The US Food and Drug Administration released an update yesterday, 8th April, showing a dramatic rise in the number of deaths that may be due to patients having allergic reactions to contaminated heparin. The agency puts the new figure at 62 deaths in the last 15 months, which is considerably more than the 19 suggested last month.
The agency released the update through its Center for Drug Evaluation and Research (CDER) website. The update shows a month by month total of deaths occurring after heparin administration reported to the FDA over the last 15 months (from January 2007 to March 2008).
The figures are arranged by the date on the report and not the date of death.
The update shows two sets of figures: one for deaths linked to heparin administration, regardless of the cause, and the other set of figures shows the number of deaths within this figure where patients showed one or more symptoms of allergic reaction or low blood pressure after being given the drug.
The first set of figures (regardless of cause) shows a total of 103 deaths in the last 15 months and the second set (the subset with one or more symptoms) shows 62.
The FDA stressed that a reported death linked to low blood pressure or allergic reactions after being given heparin does not necessarily mean the drug caused the fatality.
However, figures for 2006 showed that only three people were reported to have died after having allergic reactions following heparin administration, and the month by month chart of the last 15 months shows that 47 of the 62 deaths were reported between November 2007 and February 2008, linking the latter closely with the timing of the contaminant alert.
Heparin is a blood thinner tht has been used for decades in operating rooms, kidney dialysis and critical care centres to stop patients getting potentially fatal blood clots. The active ingredient of the drug is made from pig intestines.
Last month, FDA investigators found batches of heparin products contained a contaminant. The batches, made by Baxter International, a major supplier to the US market, all used an active ingredient sourced from one plant in China. Baxter issued a staged product recall, initially of suspect batches, and then of all heparin products once an alternative supplier was found.
The FDA said that all the reports in its latest update relate to recalled heparin products.
The China-sourced Baxter heparin contained a contaminant that has a similar chemical structure to heparin and is difficult to detect without the use of highly sophisticated lab instruments. Investigators believe the contaminant is chondroitin sulfate, made from pig cartilage, but they don’t know if it was introduced deliberately or accidentally.
The FDA recently announced it was opening an office in China so that it can oversee regulation of Chinese drug imports to the US more effectively. The plant in question was supposed to have been checked by the agency, but due to a mix up in the name of the company, it was not (the agency confused it with another company that had already been checked according to information in its supplier database).
According to the Washington Post, a Baxter spokesperson said yesterday that the company had received 38 reports of deaths linked to heparin, of which only four resulted from unexplained allergic reactions. The other 34 deaths could not be linked to the company’s heparin products because they were either caused by other conditions or the information was “too cursory” to establish such a link.
The FDA said it continues to receive and analyze reports of adverse events linked to heparin use.
Patients, doctors, nurses, pharmacists and others can report adverse events via the FDA’s Medwatch system which is available at
The FDA said that it receives more adverse event reports related to an issue when there is a lot of media interest. Every year the agency receives over 400,000 adverse event reports, the vast majority from drug manufacturers.
The FDA pointed out that because someone reports an adverse event it does not mean that the drug concerned caused the event or death.
The agency analyzes reports to see if there is good scientific evidence to support a causal link between the drug in question and the events being reported.
In most individual cases causal links are not determinable, especially since many patients have other serious conditions at the same time as the one they are taking the drug for.
Source: FDA CDER “Information on Adverse Event Reports and Heparin”, Washington Post.
Written by: Catharine Paddock, PhD