Edetate Calcium Disodium (CaEDTA)

What is edetate calcium disodium?

Edetate calcium disodium (CaEDTA) is used for the treatment of lead and zinc toxicities when oral treatment is not possible. It may be used in all species of animals.

Prior to treatment with edetate calcium disodium, it is imperative that the source of lead or zinc is removed from the animal through gastrointestinal decontamination. Edetate calcium disodium is often combined with dimercaprol treatment.

CaEDTA is used off-label in all species of pets as there are no veterinary formulations available, and medications intended for humans are prescribed (calcium disodium versenate). Compounded forms may also be available. 

Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How do I give my pet CaEDTA?

• CaEDTA comes in an injectable format to be given either under the skin (SQ) or into the vein (IV). It is recommended to give this medication under the skin (SQ) in small animals.
• This medication should only be used under the close supervision of veterinary professionals.
• IV doses should be diluted.
• DO NOT administer CaEDTA by mouth (orally) as it may increase the amount of lead absorbed from the gastrointestinal tract.
• Consider supplementing zinc when treating for lead toxicity.
• Ensure your pet maintains adequate hydration throughout treatment.

This medication should take effect quickly, within 1–2 hours. An improvement in clinical signs should follow, but it may take several days to note the effects of treatment.

What if I miss giving my pet the medication?

If you miss a dose of CaEDTA, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects from CaEDTA?

CaEDTA may cause the following side effects:

• Pain at the injection site
• Rash (reported in humans)

Serious adverse reactions associated with this drug may occur without warning and could, in rare cases, lead to death. If any of the following signs develop, stop giving edetate calcium disodium and contact your veterinarian immediately:

• Vomiting, diarrhea, and depression (could indicate reversible kidney damage)
• Fever
• Hypotension (low blood pressure)
• Tremor
• Increased liver enzymes
• Bone marrow depression
• Increased urine protein and urine glucose

Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment.

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT USE CaEDTA in:

• Pets with a hypersensitivity or allergy to this medication
• Pets that are not producing urine

USE WITH EXTREME CAUTION in:

• Pets with diminished kidney (renal) function

USE WITH CAUTION in:

• Pets that are dehydrated

Are there any drug interactions I should be aware of?

Certain medications may interact with edetate calcium disodium (CaEDTA), so be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

The following medications should be used with caution when given with CaEDTA:

• Glucocorticoids (e.g., dexamethasone, prednisone, prednisolone)
• Insulin
• Nephrotoxic drugs (e.g., aminoglycosides, amphotericin B)
• Nonsteroidal anti-inflammatory drugs (NSAIDs)

Is any monitoring needed with this medication?

• Your veterinarian will assess urinalysis (including urine sediment), hydration status, and urine output daily or every other day during treatment.
• Your veterinarian will perform a blood chemistry panel that includes renal values and phosphorus and calcium should be performed before starting treatment and at regular intervals during treatment.
• If giving CaEDTA by IV, your veterinarian will monitor heart rate and rhythm using ECG during treatment.
• Your veterinarian will monitor clinical signs during therapy in addition to measuring blood levels.
• Your veterinarian will measure blood lead and zinc levels 1–2 weeks after treatment is complete to determine whether a second course is required.
• At home, monitor for any side effects such as those noted above. If any side effects occur, discontinue use of the medication and contact your veterinarian.
• Your veterinarian will let you know when they want to reassess your pet to ensure the medication is working and not causing side effects.

How do I store CaEDTA?

• Store CaEDTA at 25°C (77°F); a temperature range of 15°C to 30°C (59°F to 86°F) is permitted for short periods.
• Do not freeze.
• Protect from light and heat.
• Store compounded forms of this medication according to the label.
• Keep medication out of reach of children and pets.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms.