technetium Tc-99m mebrofenin

Action and Spectrum

Actions and Spectrum: 

Action: 

hepatocytes in the liver primarily take up technetium tc-99m mebrofenin. It is rapidly cleared from the blood upon intravenous administration and excreted into the bile. mebrofenin, a derivative of cholic acid, serves as a cholecystographic agent, aiding in the visualization of the biliary system. 

Spectrum: 

Liver Function Assessment: tc-99m mebrofenin allows quantitative measurement of hepatocyte function. Impaired uptake or excretion of the radiopharmaceutical may indicate hepatocellular dysfunction. 

Biliary Tract Visualization: The radiopharmaceutical aids in visualizing the patency of bile ducts, enabling the detection of biliary obstructions or abnormalities. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Dermatologic: urticaria 

Skin rash 

Black Box Warning

Black Box Warning: 

None

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Patients displaying hypersensitivity or allergic reactions to technetium tc-99m mebrofenin or any of its components should avoid its administration. Hypersensitivity reactions may manifest as skin rashes, itching, facial swelling, or respiratory distress. In such cases, alternative diagnostic approaches should be considered. 

Prior Severe Reaction: Individuals who have previously exhibited severe or life-threatening reactions to radiopharmaceutical agents, including but not limited to tc-99m mebrofenin, should not be administered this agent. Anaphylactic reactions, angioedema, or other severe hypersensitivity responses indicate a heightened risk and mandate avoidance of its use. 

Acute Hepatic Dysfunction: technetium tc-99m mebrofenin is primarily employed for hepatobiliary imaging. Patients with acute hepatic dysfunction or severe impairment of liver function may experience altered pharmacokinetics and compromised imaging quality. The potential risks versus benefits should guide the clinical decision to withhold administration in such cases. 

Pregnancy and Lactation: Administration of radiopharmaceutical agents, including tc-99m mebrofenin, during pregnancy and lactation should be avoided whenever feasible. The potential radiation exposure to the developing fetus or neonate must be weighed against the clinical necessity of the imaging procedure. Pregnant or lactating individuals should be provided with alternative imaging options if available. 

Pediatric Population: Limited data exist on the safety and efficacy of technetium tc-99m mebrofenin in pediatric patients. As such, its use in the pediatric population should be approached with caution, and alternative imaging modalities may be considered, especially for younger patients. 

Impaired Renal Function: Although renal excretion of technetium tc-99m mebrofenin is minimal, individuals with severely impaired renal function may experience altered pharmacokinetics and potential retention of the radiopharmaceutical. Close monitoring and individualized dosing adjustments may be necessary in such cases. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excreted into human milk is known 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

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:  

technetium tc-99m mebrofenin is a radiopharmaceutical agent employed in nuclear medicine for hepatobiliary imaging studies. 

Pharmacodynamics:  

hepatocytes take up technetium tc-99m mebrofenin through active transport mechanisms. It is rapidly extracted and excreted into the biliary system within the liver. This process enables its accumulation in the gallbladder and subsequent release into the small intestine, mirroring the physiological pathway of bile excretion. 

Pharmacokinetics: 

Absorption  

technetium tc-99m mebrofenin is administered intravenously, ensuring rapid and complete bioavailability. Following injection, the radiopharmaceutical is swiftly absorbed into the bloodstream, facilitating its subsequent distribution to target organs. 

Distribution 

Upon entry into circulation, tc-99m mebrofenin exhibits an affinity for hepatocytes, primarily localizing within the liver parenchyma. The radiopharmaceutical distribution to hepatobiliary structures allows for visualization of the biliary system during imaging procedures. 

Metabolism 

tc-99m mebrofenin undergoes minimal metabolic alteration during its transit through the liver. Its chemical structure remains relatively stable, enabling accurate imaging of hepatobiliary function. metabolic conversion does not significantly impact the radiopharmaceutical’s diagnostic performance. 

Excretion and Elimination 

The primary route of excretion for tc-99m mebrofenin is through the biliary system. Upon reaching the liver, it is excreted into the bile, traversing the biliary tree into the gallbladder. During imaging studies, a portion of the radiopharmaceutical is released into the duodenum, allowing for visualization of the gallbladder and bile ducts. 

Adminstartion

Administration:  

The recommended adult dosage for technetium tc-99m mebrofenin is typically within the range of X to Y millicuries (mCi), administered via intravenous injection.

The precise dosage may vary based on patient characteristics and the specific imaging protocol. Intravenous administration facilitates rapid systemic distribution, with subsequent uptake by hepatocytes and biliary excretion. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: technetium tc-99m mebrofenin 

Why do we use technetium tc-99m mebrofenin?  

Hepatobiliary Imaging: technetium tc-99m mebrofenin is extensively employed for hepatobiliary imaging, aiding in the assessment of hepatocellular function and biliary patency. Clinically, it is utilized to evaluate hepatobiliary disorders, including cholecystitis, cholestasis, and hepatocellular diseases. The agent is internalized by hepatocytes, permitting dynamic scintigraphic visualization of hepatic function, bile excretion, and bile flow dynamics. 

Cholescintigraphy: This diagnostic technique, also known as a hepatobiliary scan, employs technetium tc-99m mebrofenin to assess gallbladder function and bile duct patency. Cholescintigraphy is pivotal in diagnosing acute cholecystitis, chronic cholecystitis, and biliary dyskinesia. The radiotracer’s imaging capabilities enable the identification of gallbladder ejection fraction, aiding in the characterization of gallbladder motility disorders. 

Liver Transplant Evaluation: technetium tc-99m mebrofenin plays a pivotal role in pre-operative and post-operative evaluation of liver transplant candidates and recipients. By facilitating the visualization of liver parenchyma, biliary drainage, and perfusion, the agent assists in assessing graft viability, hepatic blood flow, and biliary complications. 

Gastrointestinal Transit Studies: technetium tc-99m mebrofenin can also be applied to gastrointestinal transit studies, aiding in the evaluation of gastric emptying and intestinal motility. By tracking the movement of the radiotracer through the gastrointestinal tract, clinicians can gain valuable information about gastrointestinal disorders such as gastroparesis.