Page 204 - Pharmaceutics IV (02-06-01305)

Positron Emission Tomography (PIT)
Has been employed to study cerebral physiology ,PIT yields high
quality images that characterize substrate ,metabolism ,cellular
proliferation ,receptor density &other parameters used to identify
cancer & evaluate its response to treatment .PIT is use in mapping
regional blood flow ,oxygen metabolism, regional blood volume
,bone remodeling ,receptor gene expression .
The tracers used in PIT imaging are natural biochemicals labeled
with radionuclides of carbon ,nitrogen ,oxygen &fluorine.( Carbon
-11,Nitrogen-13 ,Oxygen -15, Fluor ine-18 radiopharmaceuticals.
Drug Antidote For Radiation Exposure
FDA approved Prussian blue (ferric hexacyanoferrate ) in 2003
to treat patients from the harmful levels of 137 Cs or thallium
exposure &contamination. At low doses ,these agents can cause

cancer .Prussian blue is administered orally in a dose of 3 g ttd in
adults & adolescents. In children aged2-12yrs ,the dose is 1g /d . It
works by trapping Cesium &thallium ions in GIT & interrupt their
reabsorption back into the systemic circulation. Prussian blue is
not
absorbed from GIT .Treatment should as soon as after exposure &
continued for 3o days, after treatment patient should be
reassessed.
Food increase its effectiveness by stimulating bile secretion.

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