Practitioners' Reporting News

Edetate Disodium

Issued April 22, 2008

Based on reports submitted to both the Food and Drug Administration (FDA) and the United States Pharmacopeia (USP), prescriptions and inpatient orders for Edetate Disodium and Edetate Calcium Disodium have been incorrectly written, interpreted, labeled and filled due to confusion resulting from the similar names and the commonly used EDTA abbreviation. Consequently, the parenteral administration of Edetate Disodium to patients who did not need calcium reduction, but instead required emergency treatment to lower lead levels in the blood, has resulted in serious and fatal consequences for patients. These errors have resulted in the recent documented deaths for two (2) children who received the incorrect medication (Edetate Disodium).

Both of the above drugs are commonly referred to as EDTA. When a physician writes an order as EDTA, clarification needs to occur as to exactly which drug is intended, Edetate Disodium or Edetate Calcium Disodium (or Calcium EDTA).

The two drugs have very different purposes and consequences of misadministration. Edetate Disodium is meant for emergency depletion of calcium due to hypercalcemia or heart arrhythmias due to digitalis toxicity. When Edetate Disodium was approved, there were very few drugs that could be administered for these purposes. Currently, many other alternatives exist that could be utilized for these purposes and the inclusion of Edetate Disodium in the formulary should be reviewed as to necessity.

Edetate Calcium Disodium is approved for the reduction of high lead levels in the blood for the treatment of acute and chronic lead poisoning, which all too frequently affects the pediatric patient. If Edetate Disodium is infused instead of Edetate Calcium Disodium, the pediatric patient may negatively respond to a drastic drop in calcium levels, which may occur in a few minutes or up to several hours after the infusion began. This parenteral infusion error has led to 11 documented deaths (1971-2007), two of which have occurred in the last 13 months.

The following are summaries of reports submitted to USP's medication error reporting programs-the USP Medication Errors Reporting (MER) Program and MEDMARX:

Case 1
During review of a patient adverse reaction and pharmacy documentation, the pharmacist discovered the child had been receiving Edetate Disodium instead of Edetate Calcium Disodium. This Wrong Drug, which had been removed by the pharmacist from the dispensing device (carousel), may have depleted the patient's calcium level which resulted in the child's death. One system in place that contributed to the error was the fill process for the automatic dispensing device (carousel). "Look-alike/sound-alike" drugs were kept stored next to each other with non distinctive labeling. Post review of the case revealed the dictionary in the inventory device had the incorrect product appear for selection when "EDE" was typed for searching. The correct product was profiled under CALCIUM. Pharmacist unfamiliarity with the dispensing device and structure of the drug dictionary contribute to this Wrong Drug error.

Case 2
A clinician in a physician outpatient office provided to an autistic child parenteral Edetate Disodium instead of Edetate Calcium Disodium. The medication administration was provided as a treatment to an autistic patient for lowering lead levels and possibly decrease the symptoms of autism. This treatment for autism has not been proven effective nor is it approved by the FDA as approved usage. The "look-alike/sound-alike" drug name has been identified as a possible cause of error in this case. Both medications fall into the category of "look-alike/sound-alike" and are clear, colorless, and odorless. Consequently, this child died from a Wrong Drug mix-up and not the lead poisoning.

This article describes the seriousness in which health care practitioners must pay close attention to the correct generic/trade name of the drug to prevent serious error/injury to patients. Errors can occur from the minute the physician writes an unclear order such as "administer EDTA," (possibly with hard to read handwriting) and continues as the pharmacist fills the prescription and the physician, nurse, or other clinician administers the medication.

Suggestions to help prevent this situation may include the below:

  • Evaluation by all hospital pharmacies, physician offices, and outpatient centers should occur to evaluate the need to stock Edetate Disodium.
  • Utilize the correct drug for the FDA approved purpose. Edetate Calcium Disodium has been approved for use in removing heavy metals from the body, such as lead in children.
  • Remember, the safety or effectiveness of Edetate Disodium has not been proven safe for removal of heavy metals from the body.
  • Do not use EDTA to order any medication. Use the full generic name indicating the inclusion of calcium when needed for the clinical purpose that is desired.
  • Include indication for treatment on the order.
  • Include the full drug name on the medication label and in the electronic dictionary to prevent error. Be alert for synonyms that are utilized for finding the drug in the electronic dictionary.
  • Label the drug name clearly on all drug dispensing devices, pharmacy bins, and delivery containers.
  • Avoid side by side drug placement for storage of Edetate Disodium and Edetate Calcium Disodium. Use "tall-man" lettering on drug dispensing devices, pharmacy bins, and delivery containers for the word, "CALCIUM".

By identifying and reporting actual and potential medication errors to the MER Program, healthcare professionals are notifying three expert organizations (USP, the Institute for Safe Medication Practices, and the FDA) as well as the manufacturers and/or labelers of the product. As illustrated in the cases described above, manufacturers are then able to implement changes to their products that will possibly prevent or reduce medication errors from occurring.

If you have similar cases to share, report them to the MER Program via a secure online form or by calling 1-800-23-ERROR (1-800-233-7767) to request a reporting form.


Readers are advised that official USP cautions and warnings for drugs appear in the USP-NF or USP DI. Unless otherwise indicated, any advice or opinions expressed herein reflect solely the judgment of USP staff. Such statements are intended for further consideration and evaluation and may or may not be applicable to a particular practice. The USP Medication Errors Reporting Program is presented in cooperation with the Institute for Safe Medication Practices.

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