Antimony toxicity

Background

  • Antimony is a metalloid and will react as a metal and nonmetal
    • Shares many similar properties with arsenic
  • Used to treat leishmaniasis and schistosomiasis
    • Most reported cases are due to complication of treatment
  • Most common forms used for treatment are trivalent and pentavalent compounds
  • Additional exposure occur from industrial exposures as inhalation of antimony dusts or fumes during processing
  • Antimony is thought to exert its toxic effects due to inactivation of various thiol-containing proteins and enzymes

Stibine

  • Most toxic form of antimony
  • Colorless gas that is formed when antimony reacts with hydrogen
    • Can result when mixing drain cleaners containing sodium hydroxide in areas with antimony ore
  • Can result in massive hemolysis

Toxicokinetics

  • Absorption
    • Inhalation
    • Ingestion
    • Transcutaneous
    • Bioavailability is 15-50%
  • Distribution
    • Predominately in highly vascular organs
    • Trivalent form seen in red blood cells
    • Pentavalent form accumulates in the liver
  • Metabolism
    • Pentavalent form is converted to trivalent form in the liver
  • Excretion
    • Trivalent form undergoes enterohepatic recirculation
    • Renal
      • Trivalent has a slow elimination with approximately 10% cleared within the first 24 hours
      • Pentavalent will have approximately 50-60% cleared within the first 24 hours

Clinical Features

Clinical features can range from mild local irritation to organ dysfunction

Differential Diagnosis

Heavy metal toxicity

Evaluation

  • BMP
  • CBC
  • Urinalysis
  • EKG to look for cardiac affects of antimony
  • Cardiac monitor to assess for arrhythmia
  • CXR
  • Cases of stibine
    • Add type and cross, and coagulation factors as transfusions are likely required
  • Serum level 0.8 - 3 μg/L (6.6-24.6 nmol/L)
  • Urine level (24 hr) 0.5-6.2 μg/L (4.1-50.1 nmol/L)

Management

Stibine

Disposition

  • Will require admission to a monitored bed, likely ICU.

References

Tarabar, A. Antimony. In: Goldfrank's Toxicologic Emergencies. 9th Ed. New York: McGraw-Hill; 2011: 1207-1213

  1. 1. Lauwers LF, Roelants A, Rosseel PM, et al. Oral antimony intoxications in man. Crit Care Med. 1990;18:324-326.