What is the treatment for mercury poisoning?

Treatment of Mercury Poisoning

For acute mercury poisoning, immediately remove the patient from the source of exposure and initiate chelation therapy with dimercaptosuccinic acid (DMSA) or dimercaptopropane-1-sulfonate (DMPS), with dimercaprol (BAL) reserved for severe cases requiring immediate intervention. 1, 2, 3

Immediate Management

Source Removal and Supportive Care

• The absolute priority is removing the patient from mercury exposure - this is more critical than any pharmacologic intervention 3
• Activate emergency medical services if the patient exhibits life-threatening symptoms including altered mental status, seizures, respiratory distress, or hemodynamic instability 4
• Contact Poison Control (1-800-222-1222 in the US) for guidance on specific management 4
• Provide aggressive supportive care including hemodynamic support, correction of acidosis and electrolyte abnormalities, and renal support as needed 1, 2

Decontamination Considerations

• Do NOT administer activated charcoal, ipecac, or attempt dilution with milk or water unless specifically directed by poison control - these interventions are not beneficial for mercury poisoning and may cause harm 4
• For elemental mercury spills on skin, remove contaminated clothing immediately to prevent ongoing exposure 5

Chelation Therapy

First-Line Chelation Agents

• DMSA (dimercaptosuccinic acid) is the preferred chelation agent for most cases of mercury poisoning due to its oral administration, favorable side effect profile, and effectiveness 1, 3
• DMPS (2,3-dimercaptopropane-1-sulfonate) is an equally effective alternative, particularly in severe poisoning or when combined with renal replacement therapy 1, 2
• Treatment with chelation typically results in resolution of symptoms within 6 months when combined with source removal 3

Severe Poisoning Protocol

• Dimercaprol (British Anti-Lewisite/BAL) should be used for severe, life-threatening mercury poisoning requiring immediate intervention, particularly with inorganic mercury salts like mercuric chloride 1, 6
• In patients developing acute renal failure, consider continuous veno-venous hemodiafiltration (CVVHDF) in combination with DMPS - this combination can remove significant amounts of mercury (up to 12.7% of ingested dose documented) 2

Clinical Assessment

Diagnostic Indicators

• Measure blood and urine mercury levels when exposure is suspected, though blood levels do not reliably predict toxicity severity 6
• Symptomatic patients typically have 24-hour urine mercury concentrations >20 mcg/L 3
• Initial blood mercury levels >3.5 mg/L (17.9 μmol/L) indicate potentially severe poisoning requiring intensive care 1

Key Clinical Manifestations to Monitor

• Early presentation (first days): Flu-like illness, nausea, vomiting, abdominal pain, fever, and rash 1, 6, 5
• Severe complications: Encephalopathy, peripheral neuropathy, nephrotic syndrome/acute renal failure, severe pneumonitis, circulatory collapse 1, 2, 6
• Pediatric-specific symptoms: Headache, anorexia, personality changes, and rash are more commonly reported 3
• Adult-specific symptoms: Myalgias, tremors, hypertension, and oral paresthesias 5, 3

Common Pitfalls

Diagnostic Delays

• Mercury poisoning is frequently misdiagnosed as viral illness due to nonspecific initial symptoms - maintain high suspicion and obtain detailed exposure history 5, 3
• Delays in diagnosis are common and can lead to continued exposure and worsening toxicity 3

Treatment Considerations

• Neurological symptoms may persist even after source removal and treatment, emphasizing the importance of early intervention 5
• Penicillamine and edetate calcium disodium are alternative chelators but are not first-line agents 6
• Multidisciplinary approach involving medical toxicologists and public health officials is frequently necessary for proper source identification and remediation 3