What is the treatment for mercuric chloride poisoning?

Treatment of Mercuric Chloride Poisoning

Immediate hemodialysis combined with chelation therapy using dimercaprol (BAL) is the recommended treatment for mercuric chloride poisoning to reduce mortality and prevent permanent organ damage.

Initial Management

• Decontamination

  • Perform gastrointestinal decontamination if presentation is within 1-2 hours of ingestion
  • Whole-bowel irrigation with polyethylene glycol solution until abdominal radiographs show clearance of radiopaque material 1
  • Activated charcoal administration (though binding capacity may be limited)

• Supportive Care

  • Establish IV access and provide fluid resuscitation for hemodynamic instability
  • Monitor for and correct electrolyte abnormalities, particularly hypokalemia 2
  • Treat acidosis if present
  • Address corrosive injuries to GI tract (mercuric chloride is highly corrosive)

Chelation Therapy

• First-line: Dimercaprol (BAL)

  • Begin immediately without waiting for confirmation of mercury levels
  • Dosing for severe mercury poisoning: 5 mg/kg initially, followed by 2.5 mg/kg 1-2 times daily for 10 days 3
  • Administer via deep intramuscular injection only
  • Most effective when started within 1-2 hours of ingestion 3

• Alternative/Additional Chelators:

  • DMPS (2,3-dimercapto-1-propanesulfonic acid) - may be more effective than BAL based on case reports 4
  • DMSA (succimer) - oral agent that can be used for continuation therapy after initial parenteral treatment 1

Renal Replacement Therapy

• Hemodialysis

  • Initiate promptly for patients with acute renal failure
  • While hemodialysis alone is ineffective for mercury removal, it's essential for managing renal failure 4, 5
  • Continue until renal function recovers

• Plasma Exchange

  • Consider for severe poisoning with very high blood mercury levels
  • More effective than hemodialysis for removing mercury from circulation 5

Monitoring and Follow-up

• Monitor blood and urine mercury levels
• Track renal function (BUN, creatinine)
• Monitor for signs of multi-organ failure
• Continue chelation until mercury levels decrease below toxic thresholds
• Follow-up for at least 4 months to ensure complete renal recovery 5

Important Considerations

• Timing is critical - treatment efficacy decreases significantly with delayed presentation
• Avoid certain chelators - do not use agents for other heavy metals like cadmium, iron, or selenium poisoning as they may form more toxic complexes 3
• Consultation - early consultation with a medical toxicologist or poison center is essential for optimal management 6
• Prognosis - complete recovery is possible even with potentially lethal doses if aggressive treatment is initiated promptly 2

Pitfalls to Avoid

• Delaying chelation therapy while awaiting confirmation of mercury levels
• Using inappropriate chelating agents (e.g., those for other heavy metals)
• Discontinuing chelation therapy too early before adequate mercury elimination
• Failing to monitor for delayed renal toxicity, which may develop days after exposure
• Overlooking the need for long-term follow-up of renal function