technetium Tc 99m exametazime

Action and Spectrum

Actions and spectrum: 

The action of Tc-99m exametazime involves its binding to the cerebral tissue in proportion to regional blood flow. It enters the brain through the blood-brain barrier and is taken up by brain cells. The radiopharmaceutical emits gamma radiation, which can be detected by a gamma camera during imaging. 

The spectrum of Tc-99m exametazime imaging is focused on evaluating cerebral blood flow and identifying abnormalities in the brain, such as ischemic stroke, brain tumor, dementia, and other neurological disorders.

It provides valuable information about regional brain perfusion and can aid in the diagnosis and management of various conditions affecting the brain. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Hypersensitivity with anaphylaxis 

Post marketing Reports 

subcutaneous tissue and Skin disorders: generalized erythema, angioedema, Rash, urticaria, pruritus 

Nervous system disorders: dizziness, Headache, paresthesia 

Gastrointestinal disorders: vomiting, Nausea 

Cardiovascular:  increased Transient blood pressure 

General disorders: Facial edema, asthenic conditions (eg, fatigue, malaise), fever 

Vascular disorders: Flushing 

Black Box Warning

Black Box Warning: 

technetium Tc 99m exametazime does not have a specific black box warning. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• Hypersensitivity: Patients with a known hypersensitivity or allergic reaction to technetium Tc 99m exametazime or any of its components should not receive the medication. 
• Pregnancy and breastfeeding: technetium Tc 99m exametazime should be avoided in pregnant or breastfeeding women unless the potential benefits clearly outweigh the risks.  
• Patient age and condition: The use of technetium Tc 99m exametazime may need to be adjusted or avoided in certain patient populations, such as infants, young children, and patients with severe renal impairment. Special considerations and dose adjustments may be necessary based on individual patient factors.

Caution: 

• Radiation exposure: technetium Tc 99m exametazime is a radiopharmaceutical that emits ionizing radiation. The potential risks associated with radiation exposure should be carefully weighed against the diagnostic benefits.  
• Renal impairment: Patients having renal impairment may require dosage adjustments or alternative imaging agents. technetium Tc 99m exametazime is primarily excreted through the kidneys, so impaired renal function can affect its clearance from the body. 
• Allergic reactions: Although rare, allergic reactions to technetium Tc 99m exametazime have been reported.  
• Interference with other medications: technetium Tc 99m exametazime may interact with certain medications, affecting its imaging accuracy.

Comorbidities: 

technetium Tc 99m exametazime is a radiopharmaceutical used for diagnostic imaging purposes, and it does not have specific comorbidities associated with its use. 

Pregnancy / Lactation

Pregnancy consideration: FDA pregnancy category: C 

Lactation: technetium Tc excreted into human milk and unknown for exametazime.  

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or 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: 

The pharmacology of technetium Tc 99m exametazime is centered around its ability to bind to specific receptors in the brain, allowing for the visualization of cerebral blood flow and the detection of abnormalities in brain function. 

technetium Tc 99m exametazime is a lipophilic compound that rapidly crosses the blood-brain barrier after intravenous administration. It binds to the cerebral endothelial cells, where it is initially trapped.

Over time, it is redistributed and taken up by brain tissue, particularly in areas with high metabolic activity. The radiotracer emits gamma radiation, which can be detected and measured using specialized imaging equipment such as a gamma camera.  

Pharmacodynamics: 

The pharmacodynamics of technetium Tc 99m exametazime are primarily related to its imaging properties in nuclear medicine. When administered intravenously, technetium Tc 99m exametazime binds to certain receptors in the brain, allowing for the visualization and assessment of cerebral blood flow and brain function.

The pharmacodynamic effects of technetium Tc 99m exametazime are seen in the images obtained during nuclear medicine scans. By assessing the distribution and intensity of the emitted gamma radiation, healthcare professionals can evaluate cerebral blood flow, identify regions of abnormal perfusion, and detect functional abnormalities in the brain. This information is useful for diagnosing and monitoring various neurological conditions, including stroke, brain tumors, and neurodegenerative diseases.  

Pharmacokinetics: 

Absorption 

technetium Tc 99m exametazime is administered intravenously, resulting in immediate and complete systemic absorption. 

Distribution 

After injection, the radiotracer rapidly distributes throughout the body, including the brain. It crosses the blood-brain barrier and accumulates in brain tissue, allowing for imaging of cerebral blood flow and brain function. 

Metabolism 

technetium Tc 99m exametazime undergoes minimal metabolism in the body. It remains unchanged and retains its imaging properties. 

Elimination and excretion 

The radiotracer is primarily eliminated from the body through renal excretion. After imaging is completed, the majority of the dose gets excreted in the urine within 24 hours. 

Adminstartion

Administration: 

technetium Tc 99m exametazime is administered intravenously as a radiopharmaceutical for imaging purposes. The injection is typically given in a healthcare setting by a trained healthcare professional, such as a nuclear medicine technologist or a radiologist. 

The dose and administration technique may vary depending on the specific imaging procedure and the patient’s condition. The radiotracer is injected into a peripheral vein, usually in the arm, using a syringe or an automated infusion system. The injection is performed slowly to minimize discomfort and ensure accurate delivery of the radiopharmaceutical. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: technetium Tc 99m exametazime 

Pronounced: [ tek-NEE-shee-um-Tc-99m-ex-a-MET-a-zeem ]  

Why do we use technetium Tc 99m exametazime? 

• Cerebral Blood Flow Imaging: technetium Tc 99m exametazime is used to assess cerebral blood flow and detect abnormalities in blood flow within the brain. It helps in the diagnosis and evaluation of conditions such as cerebrovascular diseases, brain tumors, and neurodegenerative disorders. 
• Brain Perfusion Imaging: This radiotracer is employed to evaluate brain perfusion. It assists in the detection and characterization of ischemic stroke, brain trauma, and other vascular disorders. 
• Brain Function Studies: technetium Tc 99m exametazime can be used in functional brain imaging studies to assess regional brain function. It helps in the evaluation of neurologic disorders like epilepsy, Alzheimer’s disease, and other cognitive impairments.