What is the treatment for arsenic poisoning?

Treatment for Arsenic Poisoning

The primary treatment for arsenic poisoning includes chelation therapy with agents such as dimercaptopropanol (BAL), dimercaptopropanesulfonate (DMPS), or dimercaptosuccinic acid (DMSA), with DMPS being the preferred agent for most cases of acute, subacute, and chronic arsenic toxicity. 1

Types of Arsenic and Exposure

• Arsenic exists in two main forms: inorganic (more toxic) and organic compounds (less toxic) 2
• Inorganic arsenic is classified as carcinogenic to humans by the WHO and US National Toxicology Program 2
• Main sources of exposure include contaminated drinking water and food, with water being the most concerning source in many regions 2
• Areas with high natural arsenic levels in groundwater include the Southwest, New England, upper Midwest, and Western United States 2

Clinical Manifestations

• Acute high-dose exposure can cause severe systemic toxicity and death 3
• Chronic exposure symptoms include:
  • Skin pigmentation changes and hyperkeratoses of palms and soles 4
  • Peripheral sensorimotor neuropathy 1, 4
  • Gastrointestinal disturbances 4
  • Cardiovascular symptoms 1
  • Hepatotoxicity and liver disease 4
  • Anemia and bone marrow depression 4
  • Renal dysfunction 1
  • Neurological effects including toxic delirium and encephalopathy 4
  • Sensorineural hearing loss (in some cases) 5

Treatment Protocol

Immediate Interventions

• Remove the patient from the source of exposure 2
• For acute poisoning with recent ingestion, consider gastrointestinal decontamination 1
• Provide supportive care addressing fluid balance, electrolyte abnormalities, and organ dysfunction 3

Chelation Therapy

• Chelating agents work by binding to arsenic through high-affinity interactions with thiol groups 1
• Recommended chelating agents:
  • DMPS (dimercaptopropanesulfonate) - appears most promising for alleviating symptoms in acute, subacute and chronic cases 1
  • DMSA (dimercaptosuccinic acid) - effective oral agent for less severe cases 1, 4
  • BAL (dimercaptopropanol) - consider in combination with DMPS for initial treatment of acute severe poisoning 1

Extracorporeal Treatment

• For severe cases with significant toxicity, extracorporeal treatment should be considered 2
• Intermittent hemodialysis is the preferred modality when available 2
• If hemodialysis is not available, continuous kidney replacement therapy (CKRT) is recommended 2
• Peritoneal dialysis may be used in resource-limited settings but is significantly less effective 2

Supportive Nutritional Therapy

• Micronutrient supplementation may help mitigate health effects of arsenic exposure 6
• Focus on antioxidants and nutrients that share metabolic pathways with arsenic 6
• Maintaining good folate status is important for arsenic elimination from the body 2

Special Considerations

• Pregnancy: Arsenic trioxide is highly embryotoxic and should be avoided during pregnancy 2
• Chronic exposure requires long-term monitoring for development of arsenic-related cancers (skin, lung, bladder) 2, 4
• Neurological symptoms may persist even after chelation therapy 4

Prevention Strategies

• Primary prevention through reduced exposure should be prioritized 1
• Testing of drinking water sources in high-risk areas 2
• Use of alternative water sources (e.g., bottled water) in areas with high arsenic levels 2
• Avoiding excessive consumption of foods known to contain high arsenic levels (seafood, rice products, fruit juices) 2
• Common household water filters are not effective at removing arsenic 2