Zinc DTPA and Calcium DTPA

What is DTPA (Diethylenetriamine pentaacetate)?

DTPA (Diethylenetriamine pentaacetate) is a medicine that can bind to radioactive plutonium, americium, and curium to decrease the amount of time it takes to get radioactive plutonium, americium, and curium out of the body.

The FDA has found that when produced under conditions specified in approved new drug applications (NDAs), both of these products can be safe and effective for the treatment of internal contamination with plutonium, americium, or curium.

What are plutonium, americium, and curium?

Plutonium, americium, and curium are transuranium elements (elements with atomic numbers higher than uranium). All transuranium elements are radioactive. In addition to their use in laboratory and industrial environments, these elements may be found in nuclear weapons and nuclear power plant waste.

People can become internally contaminated with these radioactive materials by inhalation, ingestion, or direct contact through wounds. Internal contamination with plutonium, americium, or curium can occur through a variety of routes including ingestion, inhalation, or direct contact through wounds. The goal of treatment with Ca-DTPA and Zn-DTPA is to enhance the removal of these radioactive contaminants and hence the risk of possible future biological effects, including the development of certain cancers which may occur years after contamination.

How does DTPA work?

DTPA comes in two forms: calcium (Ca-DTPA) and zinc (Zn-DTPA). Both forms work by tightly binding to radioactive plutonium, americium, and curium. These radioactive materials (bound to DTPA) are then passed from the body in the urine.

DTPA works best when given shortly after radioactive plutonium, americium, and curium have entered the body. The more quickly radioactive material is removed from the body, the fewer and less serious the health effects will be.

When given within the first day after internal contamination has occurred, Ca-DTPA is more effective than Zn-DTPA. After 24 hours have passed, Ca-DTPA and Zn-DTPA are equally effective.

After 24 hours, DTPA binds less effectively to radioactive plutonium, americium, and curium. However, DTPA can still work to remove these radioactive materials from the body several days or even weeks after a person has been internally contaminated.

Who can take DTPA?

Doctors and public health authorities will work together to decide who likely will benefit from DTPA treatment.

For doctors who may be administering DTPA for patients, use the following guidelines:

  • Infants (including breastfed infants) and children less than 12 years of age can be given either Ca-DTPA or Zn-DTPA.
    • The dosage of DTPA should be based on the child’s size and weight.
    • The safety and effectiveness of the inhaled route of DTPA has not been studied in children.
  • Young adults and adults internally contaminated with plutonium, americium, or curium should receive Ca-DTPA if treated within the first 24 hours after contamination. After 24 hours, if additional treatment is needed, adults should receive Zn-DTPA. If Zn-DTPA is not available, patients may receive Ca-DTPA together with a vitamin and mineral supplement that contains zinc.
  • Pregnant women should be treated with Zn-DTPA, unless the woman has very high levels of internal contamination with plutonium, americium, or curium.
    • Ca-DTPA should be used in pregnant women only to treat very high levels of internal radioactive contamination.
    • In this case, doctors and public health authorities may prescribe a single dose of Ca-DTPA, together with a vitamin and mineral supplement that contains zinc, as the first treatment.
    • After the first dose of Ca-DTPA, treatment should continue 24 hours later with a daily dose of Zn-DTPA, as needed.
  • Breastfeeding women who are internally contaminated with plutonium, americium, or curium can be treated with Ca-DTPA or Zn-DTPA.

How is DTPA given?

DTPA can be injected directly into a vein in the arm or dripped into a vein from a bag (intravenously [IV]).
Adults who have inhaled plutonium, americium, or curium can be treated with DTPA mist that is breathed into the lungs.

  • Inhaling DTPA might cause some people, especially those with asthma, to cough or wheeze.
  • The safety and effectiveness of inhaled DTPA has not been shown in children.

DTPA should be taken only as long as needed, as determined by a doctor.
Doctors might collect samples of blood, urine, and feces during DTPA treatment. These samples can tell the doctors how much radioactivity you are passing and how much remains in your body.
The length of treatment with DTPA will depend on:

  • The amount of radioactive material in your body
  • How well your body gets rid of the radioactive material with the help of DTPA.

How are Ca-DTPA and Zn-DTPA administered?

Ca-DTPA and Zn-DTPA should not be administered simultaneously. FDA recommends that, if both products are available, Ca-DTPA be given as the first dose. If additional treatment is needed, treatment should be switched to Zn-DTPA. This treatment sequence is recommended because Ca-DTPA is more effective than Zn-DTPA during the first 24 hours after internal contamination. After the initial 24 hours, Zn-DTPA and Ca-DTPA are similarly effective, but Ca-DTPA causes more loss of essential metals, such as zinc, from the body. Therefore, Zn-DTPA is preferred for maintenance therapy.

  • If Ca-DTPA is not available or treatment cannot be started within the first 24 hours after contamination, treatment should begin with Zn-DTPA.
  • If Zn-DTPA is not available, Ca-DTPA can be given for continued treatment, along with vitamin or mineral supplements that contain zinc.
  • Ca-DTPA and Zn-DTPA can be administered by nebulizer or directly into the blood stream (i.e. intravenously). If the route of internal contamination is through inhalation alone, then nebulized chelation therapy will suffice. If the routes of contamination are multiple (e.g., inhalation and through wounds), then intravenous chelation therapy is preferred.
  • The duration of treatment is dictated by the level of internal contamination and the individual’s response to therapy. Levels of internal contamination should be ascertained weekly during chelation therapy to determine when to terminate treatment.
  • Zn-DTPA is the preferred treatment for the pregnant woman with internal contamination.

How soon after internal contamination should someone receive Ca-DTPA or Zn-DTPA to avoid illness?

In most cases of contamination with transuranium elements, it is unlikely that immediate illness would occur. In order to reduce the risks of future biological effects, Ca-DTPA or Zn-DTPA should be taken as soon as possible after internal contamination, following or concurrent with distancing the individual from the radioactive source and appropriate external decontamination. However, even when treatment cannot be started right away, individuals should be given Ca-DTPA or Zn-DTPA as soon as the products are available. Treatment with Ca-DTPA or Zn-DTPA is still effective even after time has elapsed since contamination, but effectiveness decreases once these elements are trapped in the bones.

There are currently no other FDA-approved products for treating internal contamination with transuranium elements.

Facilities That May Use DTPA

  • Military bases that may be exposed to Plutonium.
  • Hospitals that may have a risk of dealing with dirty bomb victims.
  • Hospital facility that is a designated Plutonium treatment center or might treat patients from a Nuclear Reactor.
  • Other facilities that want to be prepared for similar occurrences.

Please send an email to DTPA@reliancewholesale.com if you need a quote or
would like to discuss your needs with us. Or you may call us at 866-210-1591