technetium Tc 99m mebrofenin

Absorption

Visualisation in the liver could be detected by 5 minutes and maximum liver uptake occurred at 11 minutes post-injection. Hepatic duct and gallbladder visualization occurred by 10 to 15 minutes and intestinal activity was visualized by 30 to 60 minutes in subjects with normal hepatobiliary function The mean percent injected dose remaining in the blood at 10 minutes was 17%.

The Uses of technetium Tc 99m mebrofenin

Radioactive agent.

Background

Technetium Tc 99m Mebrofenin is a diagnostic radiopharmaceutical composed of diisopropyl-iminodiacetic acid (DISIDA) attached to a technetium-99m ion. Following intravenous injection, single photon emission computer tomography (SPECT) imaging of the liver or gallbladder is performed using a gamma camera to detect the gamma rays emitted by the technetium-99m as it decays. This is possible as Technetium-99m decays by isomeric transition to technetium-99 through the release of a gamma ray. Liver and gallbladder imaging is enabled through attachment to mebrofenin as this molecule has high hepatic uptake and fast biliary excretion, resulting in improved hepatic imaging. More specifically, mebrofenin is taken up into hepatocytes through the action of OATP1B1 and OATP1B3 transporters.
Currently available within a sterile kit, Tc-99m Mebrofenin is indicated for imaging of the liver and gallbladder.

Indications

Technetium Tc 99m Mebrofenin is indicated as a hepatobiliary imaging agent.

General Description

Technetium (^99mTc) mebrofenin is a 2:1 complex ofligand:metal that is rapidly eliminated via the hepatobiliarysystem. The presence of bromine within the structureof mebrofenin makes the drug more lipophilic, and thus ithas higher hepatic extraction than other hepatobiliaryiminodiacetic acids (HIDA). Clearance from the blood isalso affected by bilirubin levels, but generally to a muchlesser extent because of the higher hepatic extraction.The clinical indication for this product is hepatobiliaryimaging.
The product is prepared by adding sodium pertechnetate(^99mTc) to the shielded vial containing mebrofenin,stannous fluoride and preservatives, and allowing the mixtureto incubate for 15 minutes. The presence of preservativesallows this kit to be used for up to 18 hours afterpreparation.
The fasting patient receives an intravenous injection of5 mCi (185 MBq), which is taken up by the hepatocytes inthe liver by active anionic transport. Patients with bilirubinlevels greater than 1.5 mg/dL may require a 10 mCi(370 MBq) dose.

Metabolism

Not Available