Recommended Treatment Regimen for Arsenic Poisoning
The recommended treatment for arsenic poisoning is chelation therapy with dimercaptosuccinic acid (DMSA) as the first-line agent, potentially combined with dimercaptopropanol (BAL) in severe acute cases, along with supportive care and extracorporeal treatments when appropriate. 1
Diagnosis and Initial Assessment
- Confirm arsenic poisoning through 24-hour urinary arsenic excretion testing
- Monitor vital parameters including airway patency, respiratory status, and hemodynamic stability
- Assess for symptoms of acute poisoning (severe nausea, vomiting, abdominal pain, diarrhea) or chronic exposure (skin changes, peripheral neuropathy)
Treatment Algorithm
Acute Severe Poisoning
Initial Stabilization
- Secure airway, breathing, and circulation
- Gastric decontamination if recent ingestion (within 1-2 hours)
Chelation Therapy
- First 48 hours: BAL (dimercaptopropanol) 3-5 mg/kg IM every 4-6 hours combined with DMSA
- After initial period: Transition to DMSA monotherapy
Extracorporeal Treatments
- Consider hemodialysis, continuous venovenous hemofiltration, or peritoneal dialysis to enhance arsenic elimination 2
Chronic Arsenic Poisoning
Primary Chelation
- DMSA (succimer) 10 mg/kg orally every 8 hours for 5 days, then every 12 hours for 14 days
- For patients unable to take oral medications, IV DMSA at 20 mg/kg/day for 5 days, then 10 mg/kg/day 2
Alternative/Adjunctive Chelation
- DMPS (dimercaptopropanesulfonate) may be used as an alternative when DMSA is unavailable
- Consider combination therapy with reduced doses of both agents to enhance efficacy 3
Monitoring During Treatment
- Daily assessment of clinical symptoms
- Regular monitoring of urinary arsenic levels until normalization
- Liver and kidney function tests
- Neurological assessment
- Electrolyte balance and hydration status
Evidence Considerations
The European LeukemiaNet guidelines extensively discuss arsenic trioxide (ATO) for treating acute promyelocytic leukemia 4, but this is distinct from treating arsenic poisoning. For actual arsenic poisoning, Praxis Medical Insights provides the most relevant guidance 1.
While BAL has historically been the standard treatment for arsenic poisoning 5, newer agents like DMSA and DMPS have several advantages:
- Higher therapeutic index (wider safety margin)
- Lower toxicity profile
- Can be administered orally or intravenously
- Do not redistribute arsenic to brain and testes as BAL may do 6
Special Considerations
- Severe acute poisoning: BAL may still have advantages in critical situations due to its lipophilicity and ability to penetrate cell membranes 6
- Chronic poisoning: DMSA or combination therapy with monoisoamyl-DMSA (MiADMSA) shows superior efficacy 3, 7
- Supportive care: Essential component of treatment, including fluid/electrolyte management and organ support
Pitfalls and Caveats
- BAL requires painful intramuscular injections and has unpleasant odor
- Hydrophilic chelators (DMSA, DMPS) may have limited efficacy against lipophilic organoarsenicals
- Extracorporeal elimination techniques may remove only small amounts of total body arsenic burden 2
- Long-term monitoring is essential due to risk of delayed complications including cancers of lung, bladder, and skin
The combined approach of appropriate chelation therapy, supportive care, and monitoring provides the best outcomes for patients with arsenic poisoning, with treatment selection based on acuity, severity, and specific clinical presentation.