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Technetium tc 99m exametazime

PubChem CID
11954234
Structure
Technetium tc 99m exametazime_small.png
Technetium tc 99m exametazime_3D_Structure.png
Molecular Formula
Synonyms
  • Tc-99m hmpao
  • Ceretec (TN)
  • Technetium Tc-99m exametazime
  • Technetium Tc 99m exametazime (USP)
  • Technetium tc 99m exametazime [USAN]
Molecular Weight
384.27 g/mol
Computed by PubChem 2.1 (PubChem release 2021.05.07)
Parent Compound
Dates
  • Create:
    2006-11-22
  • Modify:
    2025-01-25
Description
Technetium Tc-99m exametazime is a radiopharmaceutical sold under the trade name Ceretec used in 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 infections and inflammatory bowel disease. Exametazime, also known as hexamethylpropyleneamine oxime or HMPAO, acts as a chelating agent for the Tc-99m radioisotope.
Technetium tc-99m exametazime is a Radioactive Diagnostic Agent. The mechanism of action of technetium tc-99m exametazime is as a Radiopharmaceutical Activity.
A gamma-emitting RADIONUCLIDE IMAGING agent used in the evaluation of regional cerebral blood flow and in non-invasive dynamic biodistribution studies and MYOCARDIAL PERFUSION IMAGING. It has also been used to label leukocytes in the investigation of INFLAMMATORY BOWEL DISEASES.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Technetium tc 99m exametazime.png

1.2 3D Conformer

3D Conformer of Parent

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

[2,2-dimethyl-3-[(2R,3E)-3-oxidoiminobutan-2-yl]azanidylpropyl]-[(2R,3E)-3-hydroxyiminobutan-2-yl]azanide;oxo(99Tc)technetium-99(3+)
Computed by LexiChem 2.6.6 (PubChem release 2019.06.18)

2.1.2 InChI

InChI=1S/C13H26N4O2.O.Tc/c1-9(11(3)16-18)14-7-13(5,6)8-15-10(2)12(4)17-19;;/h9-10,18-19H,7-8H2,1-6H3;;/q-2;;+3/p-1/b16-11+,17-12+;;/t9-,10-;;/m1../s1/i;;1+1
Computed by InChI 1.0.5 (PubChem release 2019.06.18)

2.1.3 InChIKey

ZLRVWFDVJWKAIL-LXMACRGBSA-M
Computed by InChI 1.0.5 (PubChem release 2019.06.18)

2.1.4 SMILES

C[C@H](/C(=N/O)/C)[N-]CC(C)(C)C[N-][C@H](C)/C(=N/[O-])/C.O=[99Tc+3]
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

C13H25N4O3Tc
Computed by PubChem 2.1 (PubChem release 2019.06.18)

2.3 Other Identifiers

2.3.1 CAS

99944-78-2

2.3.2 Deprecated CAS

100504-35-6

2.3.3 UNII

2.3.4 DrugBank ID

2.3.5 KEGG ID

2.3.6 NCI Thesaurus Code

2.3.7 RXCUI

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • 99m-Tc-HMPAO
  • 99mTc-HMPAO
  • Ceretec
  • Tc 99m Exametazime
  • Tc 99m Hexamethylpropyleneamine Oxime
  • Tc-99m HMPAO
  • Tc-99m-Exametazime
  • Tc-99m-Hexamethylpropyleneamine Oxime
  • Technetium Tc 99m Exametazime
  • Technetium Tc 99m Hexamethylpropylene amine Oxime
  • Technetium Tc 99m Hexamethylpropylene-amine Oxime
  • Technetium Tc 99m Hexamethylpropyleneamine Oxime

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
384.27 g/mol
Reference
Computed by PubChem 2.1 (PubChem release 2021.05.07)
Property Name
Hydrogen Bond Donor Count
Property Value
1
Reference
Computed by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Property Name
Hydrogen Bond Acceptor Count
Property Value
7
Reference
Computed by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Property Name
Rotatable Bond Count
Property Value
8
Reference
Computed by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Property Name
Exact Mass
Property Value
384.098915 Da
Reference
Computed by PubChem 2.1 (PubChem release 2021.05.07)
Property Name
Monoisotopic Mass
Property Value
384.098915 Da
Reference
Computed by PubChem 2.1 (PubChem release 2021.05.07)
Property Name
Topological Polar Surface Area
Property Value
87.1 Ų
Reference
Computed by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Property Name
Heavy Atom Count
Property Value
21
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
329
Reference
Computed by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Property Name
Isotope Atom Count
Property Value
1
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
2
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
2
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
2
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2011.04.04)

3.2 Chemical Classes

3.2.1 Drugs

3.2.1.1 Human Drugs
Breast Feeding; Lactation; Milk, Human; Radiopharmaceuticals; Technetium Compounds; Diagnostic Agents

5 Drug and Medication Information

5.1 Drug Indication

Technetium Tc99m exametazime scintigraphy (with or without methylene blue stabilization) may be useful as an adjunct in the detection of altered regional cerebral perfusion in stroke. Tc99m exametazime without methylene blue stabilization is indicated for leukocyte labeled scintigraphy as an adjunct in the localization of intra-abdominal infection and inflammatory bowel disease.

5.2 Drug Classes

Breast Feeding; Lactation; Milk, Human; Radiopharmaceuticals; Technetium Compounds; Diagnostic Agents

5.3 FDA National Drug Code Directory

5.4 Drug Labels

Drug and label
Active ingredient and drug

5.5 Clinical Trials

5.5.1 EU Clinical Trials Register

6 Pharmacology and Biochemistry

6.1 Pharmacodynamics

During the first hour following injection of Tc99m labeled leukocytes, activity is seen in the lungs, liver, spleen, blood pool, bone marrow and the bladder. The kidneys (parenchyma and/or renal pelvis) and gall bladder may also be visualized. Over the first 1-6 hours, the Tc99m is visualized in the bowel. At 24 hours post-injection substantial colonic activity is seen.

6.2 MeSH Pharmacological Classification

Radiopharmaceuticals
Compounds that are used in medicine as sources of radiation for radiotherapy and for diagnostic purposes. They have numerous uses in research and industry. (Martindale, The Extra Pharmacopoeia, 30th ed, p1161) (See all compounds classified as Radiopharmaceuticals.)

6.3 FDA Pharmacological Classification

1 of 2
FDA UNII
3B744AG22N
Pharmacological Classes
Established Pharmacologic Class [EPC] - Radioactive Diagnostic Agent
Pharmacological Classes
Mechanisms of Action [MoA] - Radiopharmaceutical Activity
FDA Pharmacology Summary
Technetium tc-99m exametazime is a Radioactive Diagnostic Agent. The mechanism of action of technetium tc-99m exametazime is as a Radiopharmaceutical Activity.
2 of 2
Non-Proprietary Name
Pharmacological Classes
Radioactive Diagnostic Agent [EPC]; Radiopharmaceutical Activity [MoA]

6.4 Absorption, Distribution and Excretion

Absorption
Technetium Tc-99m exametazime is rapidly cleared from the blood after intravenous injection. Uptake in the brain reaches a maximum of 3.5-7.0% of the injected dose within one minute of injection. Up to 15% of the activity is eliminated from the brain by 2 minutes post injection, after which little activity is lost for the following 24 hours except by physical decay of technetium Tc99m.
Route of Elimination
About 30% of the injected dose is found in the gastrointestinal tract immediately after injection and about 50% of this is excreted through the intestinal tract over 48 hours. Also, about 40% of the injected dose is excreted through the kidneys and urine over the 48 hours after injection.
Volume of Distribution
The activity not associated with the brain is widely distributed throughout the body, particularly in muscle and soft tissue.

7 Toxicity

7.1 Toxicological Information

7.1.1 Effects During Pregnancy and Lactation

◉ Summary of Use during Lactation

Information in this record refers to the use of technetium Tc 99m exametazime (Tc 99m-hexamethylpropyleneamine oxime; Tc 99m HPAO; Tc 99m HMPAO) as a diagnostic agent. A US Nuclear Regulatory Commission subcommittee has recommended that nursing be discontinued for 24 hours after administration of all technetium Tc 99m diagnostic products to simplify guidance recommendations, although this time interval may be longer than necessary. Other experts state that breastfeeding need not be interrupted after administration of technetium Tc 99m exametazime in doses up to 500 MBq (15 mCi) to a nursing mother. However, to follow the principle of keeping exposure "as low as reasonably achievable", some experts recommend nursing the infant just before administration of the radiopharmaceutical and interrupting breastfeeding for 3 to 6 hours after the dose, then expressing the milk completely once and discarding it. If the mother has expressed and saved milk prior to the examination, she can feed it to the infant during the period of nursing interruption. Mothers need not refrain from close contact with their infants after usual clinical doses.

For white blood cells labeled with technetium Tc 99m exametazime 180 to 400 MBq, the International Atomic Energy Agency recommends that breastfeeding should be interrupted for 12 hours.

Mothers concerned about the level of radioactivity in their milk could ask to have it tested at a nuclear medicine facility at their hospital. When the radioactivity is at a safe level, she may resume breastfeeding. A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.

For nursing mothers who work with Tc 99m substances in their workplace, there is no need to take any precautions other than those appropriate for general radiation protection.

◉ Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

◉ Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

8 Literature

8.1 Consolidated References

8.2 NLM Curated PubMed Citations

8.3 Chemical Co-Occurrences in Literature

8.4 Chemical-Disease Co-Occurrences in Literature

9 Interactions and Pathways

9.1 Drug-Drug Interactions

10 Classification

10.1 MeSH Tree

10.2 NCI Thesaurus Tree

10.3 KEGG: Drug

10.4 KEGG: ATC

10.5 FDA Pharm Classes

11 Information Sources

  1. DailyMed
  2. DrugBank
    LICENSE
    Creative Common's Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/legalcode)
    https://www.drugbank.ca/legal/terms_of_use
    Technetium Tc-99m exametazime
    https://www.drugbank.ca/drugs/DB09163
  3. FDA Pharm Classes
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  4. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  5. Drugs and Lactation Database (LactMed)
  6. EU Clinical Trials Register
  7. National Drug Code (NDC) Directory
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  8. KEGG
    LICENSE
    Academic users may freely use the KEGG website. Non-academic use of KEGG generally requires a commercial license
    https://www.kegg.jp/kegg/legal.html
    Therapeutic category of drugs in Japan
    http://www.genome.jp/kegg-bin/get_htext?br08301.keg
    Anatomical Therapeutic Chemical (ATC) classification
    http://www.genome.jp/kegg-bin/get_htext?br08303.keg
  9. NCI Thesaurus (NCIt)
    LICENSE
    Unless otherwise indicated, all text within NCI products is free of copyright and may be reused without our permission. Credit the National Cancer Institute as the source.
    https://www.cancer.gov/policies/copyright-reuse
  10. NLM RxNorm Terminology
    LICENSE
    The RxNorm Terminology is created by the National Library of Medicine (NLM) and is in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from NLM. Credit to the U.S. National Library of Medicine as the source is appreciated but not required. The full RxNorm dataset requires a free license.
    https://www.nlm.nih.gov/research/umls/rxnorm/docs/termsofservice.html
    technetium Tc 99m exametazime
    https://rxnav.nlm.nih.gov/id/rxnorm/1431726
  11. Medical Subject Headings (MeSH)
    LICENSE
    Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S.
    https://www.nlm.nih.gov/copyright.html
    Technetium Tc 99m Exametazime
    https://www.ncbi.nlm.nih.gov/mesh/68019690
  12. PubChem
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