Arsenic poisoning

Question 1

What are the forms of arsenic entering the body?

Answer 1

• Inorganic arsenic salts (trivalent and pentavalent arsenites)
• Arsenates

Question 2

Most frequent sources of intoxication?

Answer 2

• Industry
• Agriculture (herbicides, insecticides)
• Wood
• Preservatives
• …

Question 3

Which are the major routes of absorption and where are they distributed?

Answer 3

Absorption in the GI and respiratory tracts

Distribution in:

• Soft tissues
• Liver and kidney (1st)
• Skin, hair, nail (2nd)

Question 4

Pharmacodynamids of arsenic?

Answer 4

• Inhibition of enzymes via sulfhydryl binding
• Interfering with oxidative phosphorylation

Question 5

Acute clinical features?

Answer 5

• Gastroenteritis, hematemesis, severe diarrhea ==> hypovolemic shock
• Arrhythmias
• CNS symptoms (encephalopathy, delirium, coma)
• Pancytopenia

Weeks later: Ascending peripheral neuropathy (may lead to neuromuscular respiratory failure)

Months later: Transverse white striate on the nails (Mees lines)

Question 6

Chronic clinical features?

Answer 6

• Weakness
• Peripheral neuropathy (stocking-glove pattern)
• Anemia
• Liver and kidney toxicity
• Skin changes:
  
  • Hyperkeratosis
  • Hyperpigmentation
• General cachexia

Question 7

Therapy in acute and chronic intoxication?

Answer 7

Acute:

• Gut decontamination
• Intensive supportive care
• Dithiol chelators

Chronic:

• Chelators?

Question 8

Arsine gas poisoning:

Source

Route of absorption

Clinical effects

Therapy

Answer 8

Most frequent source:

• Industry (manufacture of semiconductors)
  
  • From metals on the effect of acid

Route of absorption:

• Respiratory tract

Clinical features:

• Initially: dyspnea, vomiting, abdominal pain
• Later: Intravascular hemolysis, oliguric kidney failure

Therapy:

• Supportive care - Blood transfusion