Ioflupane (123I)

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Ioflupane (123I)
INN: ioflupane
Ioflupane (123I).svg
Clinical data
Trade names Datscan, Striascan, Celsunax
Other namesIoflupane (FPCIT);
[I-123] N-ω-fluoropropyl- 2β-carbomethoxy- 3β-(4-iodophenyl) nortropane
AHFS/Drugs.com Professional Drug Facts
License data
Routes of
administration
Intravenous
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability N/A
Excretion Kidney and fecal
Identifiers
  • methyl (1R,2S,3S,5S)- 3-(4-iodophenyl)- 8-(3-fluoropropyl)- 8-azabicyclo[3.2.1]octane- 2-carboxylate
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
Formula C18H23FINO2
Molar mass 431.290 g·mol−1
3D model (JSmol)
  • COC(=O)[C@@H]1[C@H]2CCC(N2CCCF)C[C@@H]1C3=CC=C(C=C3)[123I]
  • InChI=1S/C18H23FINO2/c1-23-18(22)17-15(12-3-5-13(20)6-4-12)11-14-7-8-16(17)21(14)10-2-9-19/h3-6,14-17H,2,7-11H2,1H3/t14-,15+,16+,17-/m0/s1/i20-4
  • Key:HXWLAJVUJSVENX-HFIFKADTSA-N
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Ioflupane (123I) is the international nonproprietary name (INN) of a cocaine analogue which is a neuro-imaging radiopharmaceutical drug, used in nuclear medicine for the diagnosis of Parkinson's disease and the differential diagnosis of Parkinson's disease over other disorders presenting similar symptoms. During the DaT scan procedure it is injected into a patient and viewed with a gamma camera in order to acquire SPECT images of the brain with particular respect to the striatum, a subcortical region of the basal ganglia. [7] The drug is sold under the brand name Datscan and is manufactured by GE Healthcare, formerly Amersham plc.

Contents

SPECT DaTSCAN showing normal Ioflupane ( I) uptake in the striatum. Datscan.JPG
SPECT DaTSCAN showing normal Ioflupane ( I) uptake in the striatum.

Pharmacology

Datscan is a solution of ioflupane (123I) for injection into a living test subject. [7]

The iodine introduced during manufacture is a radioactive isotope, iodine-123, and it is the gamma decay of this isotope that is detectable to a gamma camera. 123I has a half-life of approximately 13 hours and a gamma photon energy of 159 keV making it an appropriate radionuclide for medical imaging. The solution also contains 5% ethanol to aid solubility and is supplied sterile since it is intended for intravenous use. [7]

Ioflupane has a high binding affinity for presynaptic dopamine transporters (DAT) in the brains of mammals, in particular the striatal region of the brain. A feature of Parkinson's disease is a marked reduction in dopaminergic neurons in the striatal region. By introducing an agent that binds to the dopamine transporters a quantitative measure and spatial distribution of the transporters can be obtained.

Method of administration

The Datscan solution is supplied ready to inject with a certificate stating the calibration activity and time. The nominal injection activity is 185  MBq [7] and a scan should not be performed with less than 111 MBq.

Thyroid blocking via oral administration of 120 mg potassium iodide is recommended to minimize unnecessary excessive uptake of radioiodine. [8] This is typically given 1–4 hours before the injection. [7] [9]

The most convenient way to administer the IV dose is via a peripheral intravenous cannula. The scan is carried out 3 to 6 hours post injection. [8] [9]

Pharmacokinetics

Blood clearance of the radionuclide is rapid in healthy volunteers. [10] Radioactivity was 4.5% of the injected amount 5 min after injection of ioflupane (123I), falling to 2.2% at 30 min, 1.9% at 5 h, and declining to 1.3% at 24 h and 1.1% at 48 h after injection. Values were similar in both whole blood and plasma. Excretion was primarily renal.

Risks

Common side effects of ioflupane (123I) are headache, vertigo, increased appetite and formication. Less than 1% of patients experience pain at the injection site. [7]

The radiation risks are reported as low. The committed effective dose for a single investigation on a 70 kg individual is 4.6  mSv. [11] Pregnant patients should not undergo the test. It is not known if 123I-ioflupane is secreted in breast milk however it is recommended that breastfeeding be interrupted for three days after administration. [7]

See also

Related Research Articles

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<span class="mw-page-title-main">Nuclear medicine</span> Medical specialty

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<span class="mw-page-title-main">Scintigraphy</span> Diagnostic imaging test in nuclear medicine

Scintigraphy, also known as a gamma scan, is a diagnostic test in nuclear medicine, where radioisotopes attached to drugs that travel to a specific organ or tissue (radiopharmaceuticals) are taken internally and the emitted gamma radiation is captured by gamma cameras, which are external detectors that form two-dimensional images in a process similar to the capture of x-ray images. In contrast, SPECT and positron emission tomography (PET) form 3-dimensional images and are therefore classified as separate techniques from scintigraphy, although they also use gamma cameras to detect internal radiation. Scintigraphy is unlike a diagnostic X-ray where external radiation is passed through the body to form an image.

<span class="mw-page-title-main">Radionuclide angiography</span> Nuclear medicine imaging the ventricles of the heart

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4
. It is often used as a convenient water-soluble source of isotopes of the radioactive element technetium (Tc). In particular it is used to carry the 99mTc isotope which is commonly used in nuclear medicine in several nuclear scanning procedures.

<span class="mw-page-title-main">Isotopes of iodine</span> Nuclides with atomic number of 53 but with different mass numbers

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Iodine-123 (123I) is a radioactive isotope of iodine used in nuclear medicine imaging, including single-photon emission computed tomography (SPECT) or SPECT/CT exams. The isotope's half-life is 13.2230 hours; the decay by electron capture to tellurium-123 emits gamma radiation with a predominant energy of 159 keV. In medical applications, the radiation is detected by a gamma camera. The isotope is typically applied as iodide-123, the anionic form.

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<span class="mw-page-title-main">RTI-55</span> Chemical compound

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<span class="mw-page-title-main">RTI-121</span> Chemical compound

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<span class="mw-page-title-main">DaT scan</span> Diagnostic method

DaT Scan commonly refers to a diagnostic method, based on SPECT imaging, to investigate if there is a loss of dopaminergic neurons in striatum. The term may also refer to a brand name of Ioflupane (123I) tracer used for the study. The scan principle is based on use of the radiopharmaceutical Ioflupane (123I) which binds to dopamine transporters (DaT). The signal from them is then detected by the use of single-photon emission computed tomography (SPECT) which uses special gamma-cameras to create a pictographic representation of the distribution of dopamine transporters in the brain.

<span class="mw-page-title-main">Iobenguane</span> Chemical compound

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<i>ortho</i>-Iodohippuric acid Chemical compound

ortho-Iodohippuric acid is an analog of p-aminohippuric acid for the determination of effective renal plasma flow. Labelled OIH has a significantly higher clearance than other radiopharmaceutical yet developed and is eminently suitable for renography. It is eliminated mainly by tubular secretion. In patients with normally functioning kidneys, 85% of the OIH may be found in the urine 30 minutes after intravenous injection.

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References

  1. "Neurological therapies". Health Canada . 9 May 2018. Retrieved 13 April 2024.
  2. "Datscan- ioflupane i-123 injection, solution". DailyMed. 31 March 2020. Retrieved 23 April 2021.
  3. "Removal of [123I]Ioflupane From Schedule II of the Controlled Substances Act". DEA Diversion Control Division. Archived from the original on 13 May 2017. Retrieved 2016-02-09.
  4. "Datscan EPAR". European Medicines Agency (EMA). 17 September 2018. Retrieved 1 July 2021.
  5. "Striascan EPAR". European Medicines Agency (EMA). 24 April 2019. Retrieved 1 July 2021.
  6. "Celsunax EPAR". European Medicines Agency (EMA). 20 April 2021. Retrieved 1 July 2021.
  7. 1 2 3 4 5 6 7 "Datscan Summary of Product Characteristics" (PDF). European Medicines Agency. GE Healthcare. 25 July 2019.
  8. 1 2 Darcourt J, Booij J, Tatsch K, Varrone A, Vander Borght T, Kapucu OL, et al. (February 2010). "EANM procedure guidelines for brain neurotransmission SPECT using (123)I-labelled dopamine transporter ligands, version 2". European Journal of Nuclear Medicine and Molecular Imaging. 37 (2): 443–50. doi: 10.1007/s00259-009-1267-x . PMID   19838702.
  9. 1 2 Djang DS, Janssen MJ, Bohnen N, Booij J, Henderson TA, Herholz K, et al. (January 2012). "SNM practice guideline for dopamine transporter imaging with 123I-ioflupane SPECT 1.0". Journal of Nuclear Medicine. 53 (1): 154–63. doi: 10.2967/jnumed.111.100784 . PMID   22159160.
  10. Zhang M, Wang Y, Wang J, Li X, Li B (7 Apr 2023). "Safety, biodistribution and radiation dosimetry of [123I]ioflupane in healthy Chinese volunteers". EJNMMI Res. 13 (1): 30. doi: 10.1186/s13550-023-00978-3 . PMC   10082142 . PMID   37029298.
  11. "Notes for Guidance on the Clinical Administration of Radiopharmaceuticals and Use of Sealed Radioactive Sources". ARSAC. Public Health England. 13 February 2019.