Technetium (
99mTc) exametazime is a
radiopharmaceutical
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which ...
sold under the trade name Ceretec, and is used by
nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is " radiology done inside out" because it records radiation emi ...
physicians for the detection of altered regional cerebral perfusion in
stroke and other cerebrovascular diseases. It can also be used for the labelling of
leukocytes to localise intra-
abdominal
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso ...
infections and
inflammatory bowel disease. Exametazime (the part without technetium) is sometimes referred to as ''hexamethylpropylene amine oxime'' or ''HMPAO'', although correct chemical names are:
*(NE)-N-
3R)-3-3-(2R,3E)-3-hydroxyiminobutan-2-ylmino.html" ;"title="3-(2R,3E)-3-hydroxyiminobutan-2-yl.html" ;"title="3R)-3-3-(2R,3E)-3-hydroxyiminobutan-2-yl">3R)-3-3-(2R,3E)-3-hydroxyiminobutan-2-ylmino">3-(2R,3E)-3-hydroxyiminobutan-2-yl.html" ;"title="3R)-3-3-(2R,3E)-3-hydroxyiminobutan-2-yl">3R)-3-3-(2R,3E)-3-hydroxyiminobutan-2-ylmino2,2-dimethylpropyl]amino]butan-2-ylidene]hydroxylamine
*or 3,3'-((2,2,-dimethyl-1,3-propanediyl)diimino)bis-2-butanone dioxime.
Chemistry
The drug consists of exametazime as a
chelating agent
Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands ar ...
for the
radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
technetium-99m
Technetium-99m (99mTc) is a metastable nuclear isomer of technetium-99 (itself an isotope of technetium), symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical ra ...
. Both
enantiomer
In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical ant ...
ic forms of exametazime are used—the drug is
racemic
In chemistry, a racemic mixture, or racemate (), is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as racemates. ...
.
The third
stereoisomer
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...
of this structure, the
''meso'' form, is not included.
References
External links
European Association of Nuclear Medicine: CeretecGE Healthcare: Ceretec* Exametazime ligand:
Radiopharmaceuticals
Ketoximes
Technetium-99m
Amines
Racemic mixtures
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