Prussian blue
RADIOGARDASE
What it isFerric hexacyanoferrate binding thallium and caesium in the gut; radiocaesium and thallium poisoning.
Why this oneIt interrupts enterohepatic recirculation, cutting the biological half-life of caesium by about two-thirds.
What limits itIt works only on what re-enters the gut, so it does not remove what is already fixed in tissue. Constipation; blue stools.
FDA label
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| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Internal contamination with radioactive cesium (137Cs) and/or thallium | Adults & adolescents | 3 g (6 capsules) TID (9 g/day) | ||
| Internal contamination with radioactive cesium (137Cs) and/or thallium | Pediatric 2–12y | 1 g (2 capsules) TID (3 g/day) |
Renal Undefined
Hepatic Not systemically bioavailable; may be less effective in hepatic impairment due to decreased biliary excretion of cesium/thallium
Instructions
- Initiate as soon as contamination is suspected; effective even when delayed — do not withhold
- Take with food to stimulate excretion of cesium or thallium
- If unable to swallow, open capsules and mix with bland food/liquid (may color oral mucosa and teeth blue)
- Anticipate treatment ≥30 days; base duration on weekly urine/fecal radioactivity and CBC/electrolyte monitoring
Cautions
- Decreased GI motility can increase radiation absorbed dose to GI mucosa
- Constipation — monitor and treat
- Electrolyte abnormalities (hypokalemia) — monitor serum electrolytes
- Blue discoloration of feces, and of oral mucosa/dentition when capsules are opened
Adverse reactions
- Constipation (most common, ~24%)
- Hypokalemia
Pregnancy Category C; not absorbed from the GI tract, so fetal effects not expected — untreated cesium/thallium toxicity outweighs potential reproductive risk.
Lactation Excretion in milk unlikely (not absorbed), but women internally contaminated with cesium or thallium should not breastfeed.
NO BOXED WARNINGS
Principal riskIt works only on what re-enters the gut, so it does not remove what is already fixed in tissue
Classes and tags
Clinical profile
Mechanism of action: Prussian blue ballicule
