pentetate calcium trisodium

Action and Spectrum

Actions and Spectrum: 

pentetate calcium trisodium (Ca-DTPA) is a chelating agent used in medicine to treat heavy metal poisoning, specifically for removing radioactive isotopes from the body. 

The action of Ca-DTPA involves the formation of stable complexes with certain heavy metals, such as plutonium, americium, and curium, which are then excreted from the body. The chelation process is accomplished by binding the metal ions to the pentetate ligand, which has a high affinity for these metals. Once the complex is formed, it can be eliminated from the body through urine or feces. 

The spectrum of Ca-DTPA is limited to heavy metal poisoning caused by certain radioactive isotopes, specifically plutonium, americium, and curium. Ca-DTPA is ineffective against other heavy metals, such as lead or mercury, and should not be used to treat poisoning caused by these metals. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Fever 

Chills 

Anosmia 

Metallic taste 

Dermatitis 

Nausea 

Vomiting 

Pruritus 

Muscle cramps 

Diarrhea 

Trace element deficiency 

Chest pain 

Black Box Warning

Black Box Warning: 

The black box warning for pentetate calcium trisodium (Ca-DTPA) relates to its potential to cause renal toxicity. Ca-DTPA is primarily excreted through the kidneys, and in some cases, it can cause damage to the kidneys, leading to renal impairment or failure. 

Patients who receive Ca-DTPA should be monitored closely for signs of renal dysfunction, such as decreased urine output, elevated serum creatinine levels, and proteinuria. Patients with pre-existing renal impairment may be at increased risk of developing further renal damage. 

The black box warning also advises against using Ca-DTPA in patients with a history of renal impairment, and caution should be exercised when administering the drug to patients with mild to moderate renal impairment. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

There are several contraindications for the use of pentetate calcium trisodium (Ca-DTPA), including: 

• Known hypersensitivity: Ca-DTPA should not be used in patients with known hypersensitivity to the drug or its components. 
• Severe renal impairment: Ca-DTPA is primarily excreted through the kidneys, and in patients with severe renal impairment, the drug can accumulate in the body, potentially leading to further renal damage. 
• Pregnancy and breastfeeding: The safety of Ca-DTPA in pregnant condition or breastfeeding women has not been established, and the drug should only be used in these patients if the benefits outweigh the risks. 
• Pediatric patients: The safety and efficacy of Ca-DTPA in pediatric patients have yet to be established, and the drug should only be used in children if necessary and under close medical supervision. 
• Patients with anemia: Ca-DTPA can cause a decrease in serum calcium levels, exacerbating anemia in patients with pre-existing conditions. 

Caution 

Several cautions should be taken into consideration when using pentetate calcium trisodium (Ca-DTPA), including: 

• Renal impairment: Ca-DTPA is primarily excreted through the kidneys, and patients with mild to moderate renal impairment may be at enhanced risk of developing further renal damage. Caution should be exercised when administering Ca-DTPA in these patients. 
• Electrolyte imbalances: Ca-DTPA can cause a decrease in serum calcium levels, leading to electrolyte imbalances in patients with pre-existing conditions. 
• Immunocompromised patients: Ca-DTPA can increase the risk of infections in immunocompromised patients, and caution should be exercised when administering the drug. 
• Cardiovascular disease: Ca-DTPA can cause hypotension and bradycardia, and caution should be exercised when administering the drug to patients with pre-existing cardiovascular disease. 
• Neurological disorders: Ca-DTPA can cross the blood-brain barrier and cause neurological side effects, such as seizures, in patients with pre-existing neurological disorders. 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA pregnancy category: C 

Lactation:   

Excreted into human milk is Not known. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies do not show risk to the fetus in the first/later trimester.        
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women        
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.       
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.        
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.        
• Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

pentetate calcium trisodium is a chelating agent that removes certain heavy metals and radioactive material from the body. Ca-DTPA works by binding to these substances in the bloodstream, forming a stable, water-soluble complex that may then be eliminated from the body through the urine. 

Ca-DTPA is a member of the diethylenetriaminepentaacetic acid (DTPA) family of chelating agents. The compound contains three sodium ions and one calcium ion, which can displace heavy metals and radioactive materials from their regular binding sites in the body. 

Pharmacodynamics: 

Mechanism of action: pentetate calcium trisodium (Ca-DTPA) is a chelating agent that works by binding to heavy metals and radioactive materials in the body. Ca-DTPA contains three sodium ions and one calcium ion, which can displace heavy metals and radioactive materials from their regular binding sites in the body. 

Pharmacokinetics: 

Absorption 

pentetate calcium trisodium (Ca-DTPA) is administered intravenously and is rapidly distributed in the body. The compound is not absorbed from the gastrointestinal tract and has poor penetration through biological membranes, which limits its ability to enter cells and tissues. 

Distribution 

Ca-DTPA primarily distributes in the extracellular space, binding to heavy metals or radioactive materials. Once bound, Ca-DTPA forms a stable complex excreted by the kidneys through urine. 

Metabolism 

The body does not metabolize Ca-DTPA. 

Elimination and Excretion 

Once bound, Ca-DTPA forms a stable complex excreted by the kidneys through urine. 

Ca-DTPA has a short half-life of approximately 30 minutes in the body and is primarily excreted unchanged in the urine. 

Adminstartion

Administration: 

Intravenous administration 

pentetate calcium trisodium (Ca-DTPA) is typically administered by intravenous infusion. The dose, duration of treatment will depend on the severity of the heavy metal poisoning and the specific heavy metal involved. 

Ca-DTPA should only be administered by a healthcare professional experienced in managing heavy metal poisoning. The drug should be administered slowly over 30 to 60 min to minimize the risk of adverse reactions, such as hypotension and bradycardia. 

Before administration, patients should be assessed for signs of renal impairment or other medical conditions that may enhance the risk of adverse reactions to Ca-DTPA. Patients should also be monitored during and after administration for signs of renal dysfunction, such as decreased urine output and elevated serum creatinine levels. 

In severe heavy metal poisoning cases, multiple doses of Ca-DTPA may be necessary, and patients may require hospitalization for close monitoring and management of their condition. 

It is important to note that Ca-DTPA is a prescription drug and should only be used under the guidance of a physician. Patients should inform their healthcare provider of pre-existing medical conditions or allergies before receiving Ca-DTPA. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: pentetate calcium trisodium 

Why do we use pentetate calcium trisodium? 

pentetate calcium trisodium (Ca-DTPA) is a chelating agent primarily used to treat heavy metal poisoning, particularly lead poisoning. It works by binding to heavy metals in the body, which can then be eliminated through the urine. Ca-DTPA is not practical for all types of heavy metal poisoning but is particularly effective for treating lead poisoning. 

In addition to heavy metal poisoning, Ca-DTPA has also been used to treat certain types of radiation exposure, such as exposure to plutonium or americium. It can help to remove these radioactive materials from the body and reduce the risk of radiation-induced health problems. 

Ca-DTPA has also been used in some medical imaging procedures, particularly those involving radioactive materials. In these cases, Ca-DTPA is used as a contrast agent to help improve the visibility of specific tissues or organs on imaging scans. 

It is important to note that Ca-DTPA should only be used when the benefits outweigh risks, and its use should be reserved for cases of heavy metal poisoning or radiation exposure where no alternative treatments are available. Ca-DTPA is a prescription drug and should only be used under the guidance of a physician.