Drug Monograph
Full clinical overview, indications, dosage references & safety notes.
Overview
Edetate calcium disodium (CaEDTA; Calcium Disodium Versenate) is a heavy metal chelating agent used in veterinary medicine for the treatment of lead and zinc toxicosis in dogs and cats. It is typically administered parenterally and is considered when oral chelation therapy is not feasible.
CaEDTA is not absorbed effectively from the gastrointestinal tract and should not be given orally. It is commonly administered via the subcutaneous route in small animals, with rapid renal elimination of the drug and its metal complexes.
Mechanism of Action (MOA): CaEDTA binds divalent and trivalent metal ions such as lead and zinc, forming stable, water-soluble complexes that are excreted in the urine. This process reduces circulating metal concentrations and enhances elimination from the body.
Indications
Edetate calcium disodium (CaEDTA) is used in dogs and cats as a chelating agent for the management of heavy metal toxicosis, particularly when rapid reduction of circulating metal levels is required or when oral therapy is not practical.
- Lead toxicosis: Primary indication for treatment of lead poisoning, especially in moderate to severe cases or when oral chelation is not feasible.
- Zinc toxicosis: Used to enhance elimination of zinc in cases of toxicity.
- Adjunctive therapy: May be used in combination with other chelating agents (e.g., dimercaprol) in severe or complicated cases.
Dosage (Reference)
Dog
In dogs, edetate calcium disodium (CaEDTA) is used for the treatment of lead and zinc toxicosis. Therapy typically involves repeated dosing over several days, with careful attention to hydration and removal of the source of toxicity.
| Clinical use | Route | Dose | Frequency | Notes |
|---|---|---|---|---|
| Lead / zinc toxicosis | SC | 25 mg/kg | q6h | Dilute in 5% dextrose to ~10 mg/mL; treat for 5 days. |
| IV protocol (lead poisoning) | Slow IV | 75 mg/kg/day (divided | q6h | Administer as 4 equal doses; dilute in 0.9% NaCl or 5% dextrose. |
| Maximum total daily dose | — | ≤ 2000 mg/dog/day | — | Do not exceed this total daily dose. |
• Remove the source of lead or zinc before initiating therapy (e.g., GI decontamination).
• Maintain adequate hydration throughout treatment to reduce nephrotoxicity risk.
• Administer doses in divided intervals (every 6 hours) over 2–5 days.
• Treatment courses may be repeated after 2–3 days if clinical signs persist.
• Avoid oral administration as it may increase gastrointestinal absorption of lead.
• Dilution is required before administration; commonly prepared in 5% dextrose solutions.
Cat
In cats, CaEDTA is used similarly for lead and zinc toxicosis, with dosing protocols adjusted for body size and careful monitoring for adverse effects.
| Clinical use | Route | Dose | Frequency | Notes |
|---|---|---|---|---|
| Lead / zinc toxicosis | SC | 27.5 mg/kg | q6h | Dilute in 15 mL of 5% dextrose; treat for 5 days. |
• Therapy duration is typically 5 days; repeat courses may be required if signs persist.
• Ensure adequate hydration during treatment.
• Remove the source of heavy metal exposure prior to therapy.
• Monitor closely for adverse effects, particularly renal toxicity.
• Administer only via parenteral routes; avoid oral use.
Warnings & Precautions
Edetate calcium disodium (CaEDTA) must be used cautiously in dogs and cats due to its potential for nephrotoxicity and its dependence on renal elimination. Proper case management, including removal of the toxin source and supportive care, is essential for safe and effective treatment.
- Renal disease: Contraindicated in patients with anuria and should be used with extreme caution in those with impaired renal function due to increased risk of drug accumulation and nephrotoxicity.
- Nephrotoxicity risk: Dose-dependent renal tubular damage may occur; ensure adequate hydration and monitor renal parameters during therapy.
- Route of administration: Subcutaneous administration is preferred in small animals; rapid IV administration may lead to serious complications including increased intracranial pressure.
- Lead/zinc source removal: Treatment will be ineffective if the source of heavy metal exposure is not eliminated prior to or during therapy.
- GI tract metal presence: Avoid use if lead or zinc remains in the gastrointestinal tract, as this may prolong or worsen exposure.
- Oral administration contraindicated: Should not be given orally, as it may increase gastrointestinal absorption of lead.
- Drug name confusion: Do not confuse with edetate disodium (sodium edetate), which can cause severe hypocalcemia and is not indicated for lead poisoning.
Drug Interactions
Edetate calcium disodium (CaEDTA) may interact with medications that affect renal function or rely on metal ions for activity. These interactions may increase toxicity risk or alter the effectiveness of concurrent therapies.
- Glucocorticoids (e.g., dexamethasone, prednisolone): Concurrent use may increase the risk of renal toxicity.
- Nephrotoxic drugs (e.g., aminoglycosides, amphotericin B): Increased risk of nephrotoxicity when used together; use cautiously and monitor renal function.
- NSAIDs (e.g., carprofen, meloxicam, robenacoxib): May increase the risk of renal toxicity when administered concurrently.
- Zinc insulin preparations (e.g., NPH, PZI): May reduce the duration of insulin action by chelating zinc, leading to decreased sustained effect.
Side Effects & Overdose
Side Effects
Adverse effects of edetate calcium disodium (CaEDTA) are primarily related to renal toxicity and local irritation, with additional systemic effects reported in dogs. Most effects are dose-dependent and may be minimized with proper dosing and supportive care.
- Renal toxicity: Dose-dependent renal tubular necrosis is the most serious adverse effect; may present as nephrosis with glycosuria, proteinuria, or hematuria.
- Gastrointestinal signs: Vomiting and diarrhea may occur, particularly in dogs.
- Depression: Lethargy or decreased activity may be observed in dogs during treatment.
- Injection site reactions: Pain at injection site is common; thrombophlebitis may occur with IV administration.
- Fluid and electrolyte effects: May cause transient hypotension or alterations related to fluid balance.
- Hematologic effects: Rarely, bone marrow suppression may occur with prolonged or high-dose therapy.
- Zinc depletion: Long-term therapy may lead to zinc deficiency due to chelation.
Overdose
Overdose of CaEDTA may increase the severity of adverse effects, particularly nephrotoxicity. Although acute toxicity data are limited, excessive exposure requires prompt supportive management.
- Exaggerated renal injury: Increased risk of severe nephrotoxicity with high doses.
- Management: Discontinue therapy and provide supportive care, including fluid therapy to maintain renal perfusion.
- Monitoring: Close monitoring of renal function and clinical status is essential.
Key Notes
Practical clinical points that help optimize the safe and effective use of edetate calcium disodium (CaEDTA) in dogs and cats in everyday veterinary practice:
- Limited CNS penetration: Poor penetration into the central nervous system may limit effectiveness in advanced cases with neurologic involvement.
- Short half-life: Rapid elimination requires frequent dosing schedules to maintain therapeutic effect.
- Extracellular distribution: Primarily remains in extracellular fluid, influencing its chelation efficiency and clinical response.
- Variable metal binding efficiency: Although capable of binding several metals, its clinical effectiveness is greatest for lead and zinc.
- Adjunctive supplementation: Thiamine supplementation may improve clinical response in some cases of lead toxicity.
Calculate Any Dose Instantly
Use our smart dose calculator to get accurate dosing for 500+ veterinary drugs — adjusted for species, weight, and route.
