The term “EDTA” is often used to refer to two different drugs that bind to (“chelate”) certain molecules within the body. This binding speeds the elimination of these molecules from the body. For example, when one type of EDTA drug is injected into the blood stream, it binds to calcium and speeds excretion of calcium through the kidneys. This type of EDTA drug has been used to treat high blood levels of calcium. The other type of EDTA drug strongly binds to lead and has been used to treat patients with lead poisoning.
2. What are the names of the two EDTA drugs?
There are two drugs approved by the FDA that have similar names are easily confused. To add to the confusion, both drugs are commonly referred to only as the abbreviation, “EDTA.” One drug is named “Calcium Disodium Versenate” and is also known by the chemical name of edetate calcium disodium. This drug is approved by the FDA to lower blood lead levels among patients with lead poisoning. The other drug is marketed as “Endrate” and is also known by the chemical name of edetate disodium. This drug is approved by the FDA for use in selected patients with high blood calcium levels (hypercalcemia) as well as for use among patients with heart rhythm problems due to intoxication with the drug, digitalis.
3. What is the problem with the EDTA drugs?
The two EDTA drugs have established names that are easily confused and both are referred to in clinical practice as “EDTA.” This confusion has resulted in medication errors in which some patients have received the wrong drug, which has been fatal in some cases or caused serious adverse reactions in others. The error is especially dangerous when edetate disodium is erroneously given to a patient who is supposed to receive edetate calcium disodium.
The two EDTA drugs have different approved uses and significantly different effects. For example, edetate disodium is more likely to cause severe decreases in blood calcium levels. A severe decrease in blood calcium levels due to the erroneous administration of edetate disodium has resulted in death, predominantly among pediatric patients, who were to be treated for lead poisoning with edetate calcium disodium. As noted below, FDA has special concerns regarding the use of edetate disodium and is reconsidering the overall risks and benefits of the drug.
4. How many people have died as a result of receiving edetate disodium?
FDA has received reports of 11 deaths associated with the use of edetate disodium. These deaths were reported over the time period from 1971 through 2007. Most recently, two reports were received in 2003, two reports in 2005 and one report was received in 2007. Nine of the deaths were reported following the administration of edetate disodium (by its specific name). A specific EDTA drug was not identified in two cases. Instead, these two death reports simply referred to use of “EDTA.”
5. How many deaths have been reported to FDA as due to errors in which edetate disodium was confused with another drug?
Seven of the 11 deaths resulted from confusion of edetate disodium with another drug. In five cases, edetate disodium was administered instead of edetate calcium disodium. In two cases, edetate disodium was administered instead of the drug, Etomidate. Etomidate is not a form of EDTA.
6. What action is FDA considering to address concerns related to these medication errors?
Since the time of FDA approval of edetate disodium for use in the treatment of hypercalcemia or digitalis toxicity, multiple new drugs have been developed and marketed for treatment of these same conditions. Based on the availability of other drugs that can be used for the indications for which edetate disodium was approved, and the safety issues related to edetate disodium, FDA is reconsidering the overall risks and benefits of edetate disodium to determine the most appropriate action. FDA is also issuing a Public Health Advisory regarding edetate disodium.
7. What action is FDA considering regarding edetate calcium disodium?
FDA is issuing a Public Health Advisory regarding the medication errors involving edetate disodium and edetate calcium disodium. FDA is not considering additional action regarding edetate calcium disodium at this time. Edetate calcium disodium is approved for use in the treatment of lead poisoning. Few drugs are available for treatment of this serious condition. Additionally, most of the deaths following administration of an EDTA drug have involved medication errors in which edetate disodium was given instead of edetate calcium disodium. FDA has not received reports of any deaths resulting from the administration of edetate calcium disodium in error.
8. Are the EDTA drugs used for purposes other than those described in the product labels for the drugs?
Yes, both EDTA drugs have been used in various forms of “chelation” therapies that are purported to cleanse the body of various chemicals (such as mercury-containing chemicals) or to improve the cardiovascular system. For example, “chelation” has been proposed as a treatment for autism or hardening of the arteries. The FDA has not approved the EDTA drugs for these purposes. FDA has not received clinical data sufficient to support either the safety or efficacy of EDTA drugs when they are used for these “chelation” purposes.
9. Is the FDA recommending that hospitals not stock edetate disodium?
If hospitals or clinics currently stock edetate disodium and edetate calcium disodium, based on the medication errors involving the two drugs, FDA recommends that the facilities reconsider whether it is wise to stock both of these drugs, especially edetate disodium. Having both EDTA drugs in stock may lead to confusion and medication errors.
FDA encourages healthcare personnel to always vigilantly double check the name of any EDTA drug to be sure only the correct drug is administered to a patient.
10. Does FDA have a timeline for the completion of its review of the safety and efficacy of edetate disodium ?
FDA does not have a specific timeline but hopes to complete its review of the safety and efficacy of edetate disodium within several weeks.
11. I received edetate disodium in the past. Am I at risk for death or serious complications?
Deaths and serious reactions following edetate disodium administration have all been reported within minutes to hours following administration of the drug. The major risks are thought to apply only to the short period of time after administration of the drug.
12. Whom should I contact if I have questions about EDTA?
You should talk with your healthcare provider (for example, your doctor, nurse, or pharmacist) about EDTA, your clinical condition and all your medications.
This article was posted on January 17, 2008.