99mTc-Disofenin
99mTc-Disofenin Uses, Dosage, Side Effects, Food Interaction and all others data.
99mTc-Disofenin is a radiopharmaceutical agent used in hepatobiliary imaging for diagnostic purposes. It is well suited for both planar and single photon tomographic scintigraphy to quantitatively measure the function of liver, gallbladder and bile ducts and detect any anatomical changes in the hepatobliary system. It is available as an intravenous injection in a preparation kit under the name Hepatolite. Technetium Tc-99m is a metastable nuclear isomer and disofenin is an iminodiacetic acid derivative with no known pharmacologic actions at the doses recommended. However disofenin is the most commonly used iminodiacetic acid since it has a high liver to renal extraction and its hepatic uptake is not as highly dependent on serum bilirubin levels (a competitive inhibitor for liver uptake) as are other tracers from the iminodiacetic acid.
Technetium Tc99m is a medical radioisotope that is taken up by the liver and accumulates in the hepatobiliary system. Non-visualization of the gallbladder 4 hours after administration of Hepatolite following a 2-6 hour fast and in the presence of activity in the small intestine is indicative of a diagnosis of acute cholecystitis in an otherwise healthy individual. Under the same conditions in an otherwise healthy person, visualization of the gallbladder during a 1 hour scintigraphy is effective in excluding a diagnosis of acute cholecystitis. If the gallbladder is not visualized by 1 hour, scanning must continue for four hours or until the gallbladder is visualized . Morphine can be administered to shorten the scanning time and improve visualiation in failure of visualization of the gallbladder with Technetium Tc99m disofenin.
| Trade Name | 99mTc-Disofenin |
| Generic | Technetium Tc-99m disofenin |
| Technetium Tc-99m disofenin Other Names | 99mTc-DISIDA, 99mTc-Disofenin, Technetium (99mTc) disofenin, Technetium Tc 99m Disofenin, Technetium-99m-Diisopropyliminodiacetic Acid |
| Type | |
| Formula | C18H26N2O5Tc |
| Weight | Average: 449.321 Monoisotopic: 449.090426499 |
| Protein binding | Technetium Tc 99M-iminodiacetic acid complex is thought to bind to plasma proteins, mainly albumin, following intravenous administration which decreases renal excretion and increases hepatic uptake. The radioactive agent and protein complex dissociates after hepatic uptake into the hepatocytes through carrier-mediated non-sodium-dependent membrane transport . |
| Groups | Approved |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
99mTc-Disofenin is a radiopharmaceutical diagnostic agent used for hepatobiliary scans.
Technetium Tc99m Disofenin is indicated as a hepatobiliary imaging agent. Hepatolite is indicated in the diagnosis of acute cholecystitis as well as to rule out the occurrence of acute cholecystitis in suspected patients with right upper quadrant pain, fever, jaundice, right upper quadrant tenderness and mass or rebound tenderness, but not limited to these signs and symptoms.
99mTc-Disofenin is also used to associated treatment for these conditions: Gallbladder Inflammation
How 99mTc-Disofenin works
Gallbladder visualization and visualization of intestinal activity occurs by 60 minutes post-injection in individuals with normal hepatobiliary function. Radiopharmaceutical agent is delivered to liver sinusoids via the portal vein and hepatic artery to diffuse through the pores in the endothelial lining to bind to a specific membrane bound carrier, which transports the tracer across the hepatocyte membrane and into the hepatocyte . Once inside the hepatocyte, the tracer may be bound by various enzymes and/or undergo metabolism.
Toxicity
No long-term animal studies have been performed to evaluate carcinogenic potential or whether Technetium Tc99m Disofenin affects fertility in males or females. There is reported evidence of reproductive toxicity as well as mutagenicity in human leukocytes in vitro. LD50 value in rats following intravenous injection is 7.8mg/kg. Adverse effects from injection include itching at the site of injection progressing to erythema multiforme, and rare cases of nausea and chills.
Food Interaction
- Take on an empty stomach. This diagnostic agent should be administered to fasted patients (ideally at least 4 hours post-intake).
Volume of Distribution
Technetium Tc99M disofenin is distributed to various tissues including blood, kidney, liver, urinary bladder and predominantly stomach and intestines .
Elimination Route
In fasting normal individuals, peak liver uptake occurs by 10 minutes post-injection and peak gallbladder accumulation by 30-40 minutes post-injection . Hepatic uptake is about 88%.
Half Life
Technetium Tc99m decays by isomeric transition with a physical half-life of 6.02 hours but the Technetium Tc99M disofenin complex displays a hepatic elimination half life of 19 minutes .
Clearance
Technetium Tc 99M Disofenin is rapidly cleared from the circulation of normal individuals following intravenous administration; about 8% of the injected activity remains in the circulation 30 minutes post-injection. As the serum bilirubin level increases, the blood clearance becomes progressively delayed .
Elimination Route
About 9% of the administered activity is excreted in the urine over the first two hours post-injection. The remainder of the activity is essentially quantitatively cleared through the hepatobiliary system . Technetium Tc99M disofenin is excreted into the intrahepatic biliary ducts via active transport and is further taken to the extrahepatic bile via choleresis. It may enter the duodenum directly or be stored in the gallbladder for later release. Once inside the intestines, DISIDA does not enter the enterohepatic circulation .
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