Gadoxetic acid

Toxicity

LD50, oral, rat = 18100 mg/kg; LD50, oral, mouse = 14500 mg/kg; LD50, IV, rat = 3600 - 7300 mg/kg; LD50, IV, mouse = 5400 - 10900 mg/kg; LD50, IV, dog = >2200 mg/kg

Indications

Gadoxetate is used as a contrast medium for magnetic resonance imaging (MRI) to detect and characterize lesions in the liver.

Background

Gadoxetic acid (gadoxetate) is a paramagnetic gadolinium-containing contrast agent in which its salt form, gadoxetate disodium, is used for intravenous injection. Ethoxybenzyl diethylenetriaminepentaacetic acid is the moiety that chelates with a gadolinium ion and forms a stable complex with it to make up the drug. It is marketed by Bayer HealthCare Pharmaceuticals and FDA approved on July 3, 2008.

Pharmacokinetics

Gadoxetate disodium is an amphipathic compound in which gadoxetate is hydrophillic and its moiety, the ethoxybenyzl group, is lipophillic. Consequently, gadoxetate disodium has a biphasic mode of action in which it first distributes into the extracellular space after bolus injection and then hepatocytes selectively takes up the drug.

Metabolism

Gadoxetate disodium is not metabolized.