Pharmacology Of Gadobenate Dimeglumine

Indication	Gadobenate Dimeglumine is an MRI contrast agent used primarily for MR imaging of the liver. It can also be used for MRI of the heart, as well as and central nervous system in adults to visualize lesions with abnormal brain vascularity or abnormalities in the blood brain barrier, the brain, spine, or other associated tissues.
Pharmacodynamics	Gadobenate dimeglumine shares the pharmacokinetic properties of the ECF contrast agent gadopentetate dimeglumine; however, gadobenate differs in that is also selectively taken-up by hepatocytes and excreted via the bile (up to 5% of dose). The elimination half-life of gadobenate dimeglumine is approximately 1 hour. It is not metabolized.
Mechanism of action	Based on the behavior of protons when placed in a strong magnetic field, which is interpreted and transformed into images by magnetic resonance (MR) instruments. Paramagnetic agents have unpaired electrons that generate a magnetic field about 700 times larger than the proton's field, thus disturbing the proton's local magnetic field. When the local magnetic field around a proton is disturbed, its relaxation process is altered. MR images are based on proton density and proton relaxation dynamics. MR instruments can record 2 different relaxation processes, the T1 (spin-lattice or longitudinal relaxation time) and the T2 (spin-spin or transverse relaxation time). In magnetic resonance imaging (MRI), visualization of normal and pathological brain tissue depends in part on variations in the radiofrequency signal intensity that occur with changes in proton density, alteration of the T1, and variation in the T2. When placed in a magnetic field, Gadobenate Dimeglumine shortens both the T1 and the T2 relaxation times in tissues where it accumulates. At clinical doses, Gadobenate Dimeglumine primarily affects the T1 relaxation time, thus producing an increase in signal intensity. Gadobenate Dimeglumine does not cross the intact blood-brain barrier; therefore, it does not accumulate in normal brain tissue or in central nervous system (CNS) lesions that have not caused an abnormal blood-brain barrier (e.g., cysts, mature post-operative scars).
Absorption	Not Available
Volume of distribution	Not Available
Protein binding	Plasma protein binding is low, weak, and transient.
Metabolism	Not metabolized.
Route of elimination	Gadobenate ion is eliminated predominately via the kidneys, with 78% to 96% of an administered dose recovered in the urine.
Half life	1 hour
Clearance	0.093 +/- 0.010 L/hr/kg [healthy male subjects receiving 3 single-dose IV administration with doses from 0.005-0.4 mmol/kg]
Toxicity	Gadolinium-based radiocontrast agents like gadobenate dimeglumine are cytotoxic to renal cells. The toxic effects include apoptosis, cellular energy failure, disruption of calcium homeostasis, and disturbance of tubular cell polarity, and are thought to be linked to oxidative stress.