Heavy Metals Intoxications and Chelators

What is the main mechanism of heavy metal toxicity?

Enzyme inhibition and oxidative stress

Which heavy metal has no biologic function?

Lead

Which metal is essential but toxic in excess?

Iron

What is the main function of chelators?

Bind metals and enhance excretion

Which metal is most harmful to children CNS?

Lead

What percentage of lead binds RBCs?

99%

Where is most lead stored in adults?

Bone

What is the half-life of lead in bone?

Years to decades

What increases lead absorption?

Iron deficiency

What is classic neuropathy in lead toxicity?

Wrist drop

Which enzymes are inhibited by lead?

ALA dehydratase and ferrochelatase

What lab finding suggests lead poisoning?

Basophilic stippling

What compound increases in lead toxicity?

Zinc protoporphyrin

What type of anemia occurs in lead poisoning?

Microcytic hypochromic

What is classic triad of chronic lead poisoning?

Headache, abdominal pain, anemia

What is lead colic?

Severe abdominal pain

What renal condition is linked to lead?

Saturnine gout

What is gold standard test for lead?

Blood lead level

When do you chelate children?

≥45 mcg/dL

What is first step in lead poisoning management?

Remove exposure

What is treatment for severe lead poisoning?

Dimercaprol + EDTA

What oral chelator is used after acute therapy?

Succimer

What phenomenon occurs after chelation?

Rebound from bone

What is most toxic form of arsenic?

Trivalent As3+

What is best test for arsenic poisoning?

Urine arsenic

What is hallmark of acute arsenic poisoning?

Severe GI distress and shock

What delayed complication occurs in arsenic?

Peripheral neuropathy

What nail finding occurs in arsenic poisoning?

Mees lines

What skin finding is classic in chronic arsenic?

Raindrop pigmentation

What is first-line chelator for arsenic?

Dimercaprol or DMPS

What gas form of arsenic causes hemolysis?

Arsine gas

What is major complication of arsine gas?

Renal failure

What metal binds sulfhydryl groups strongly?

Mercury

What is classic triad of chronic mercury toxicity?

Tremor, erethism, gingivostomatitis

What is erethism?

Neuropsychiatric changes

What condition is caused by methylmercury?

Minamata disease

What is major target of methylmercury?

CNS

What is best biomarker for methylmercury?

Hair levels

Which form of mercury causes GI and renal damage?

Inorganic mercury

Which form causes pneumonitis?

Elemental mercury inhalation

What is treatment for mercury poisoning?

DMPS or succimer

Which chelator should be avoided in chronic mercury?

Dimercaprol

What chelator is used for iron poisoning?

Deferoxamine

What is classic urine color in deferoxamine therapy?

Red-orange

Which chelator is oral for iron overload?

Deferasirox

Which iron chelator causes agranulocytosis?

Deferiprone

Which chelator is used for Wilson disease?

Penicillamine

What vitamin deficiency is caused by penicillamine?

Vitamin B6

Which chelator is safest modern BAL?

DMPS

What is target of Prussian blue?

Cesium and thallium

How does Prussian blue work?

Binds metals in gut

What is the main mechanism of heavy metal toxicity?

Enzyme inhibition and oxidative stress

Which heavy metal has no biologic function?

Lead

Which metal is essential but toxic in excess?

Iron

What is the main function of chelators?

Bind metals and enhance excretion

Which metal is most harmful to children CNS?

Lead

What percentage of lead binds RBCs?

99%

Where is most lead stored in adults?

Bone

What is the half-life of lead in bone?

Years to decades

What increases lead absorption?

Iron deficiency

What is classic neuropathy in lead toxicity?

Wrist drop

Which enzymes are inhibited by lead?

ALA dehydratase and ferrochelatase

What lab finding suggests lead poisoning?

Basophilic stippling

What compound increases in lead toxicity?

Zinc protoporphyrin

What type of anemia occurs in lead poisoning?

Microcytic hypochromic

What is classic triad of chronic lead poisoning?

Headache, abdominal pain, anemia

What is lead colic?

Severe abdominal pain

What renal condition is linked to lead?

Saturnine gout

What is gold standard test for lead?

Blood lead level

When do you chelate children?

≥45 mcg/dL

What is first step in lead poisoning management?

Remove exposure

What is treatment for severe lead poisoning?

Dimercaprol + EDTA

What oral chelator is used after acute therapy?

Succimer

What phenomenon occurs after chelation?

Rebound from bone

What is most toxic form of arsenic?

Trivalent As3+

What is best test for arsenic poisoning?

Urine arsenic

What is hallmark of acute arsenic poisoning?

Severe GI distress and shock

What delayed complication occurs in arsenic?

Peripheral neuropathy

What nail finding occurs in arsenic poisoning?

Mees lines

What skin finding is classic in chronic arsenic?

Raindrop pigmentation

What is first-line chelator for arsenic?

Dimercaprol or DMPS

What gas form of arsenic causes hemolysis?

Arsine gas

What is major complication of arsine gas?

Renal failure

What metal binds sulfhydryl groups strongly?

Mercury

What is classic triad of chronic mercury toxicity?

Tremor, erethism, gingivostomatitis

What is erethism?

Neuropsychiatric changes

What condition is caused by methylmercury?

Minamata disease

What is major target of methylmercury?

CNS

What is best biomarker for methylmercury?

Hair levels

Which form of mercury causes GI and renal damage?

Inorganic mercury

Which form causes pneumonitis?

Elemental mercury inhalation

What is treatment for mercury poisoning?

DMPS or succimer

Which chelator should be avoided in chronic mercury?

Dimercaprol

What chelator is used for iron poisoning?

Deferoxamine

What is classic urine color in deferoxamine therapy?

Red-orange

Which chelator is oral for iron overload?

Deferasirox

Which iron chelator causes agranulocytosis?

Deferiprone

Which chelator is used for Wilson disease?

Penicillamine

What vitamin deficiency is caused by penicillamine?

Vitamin B6

Which chelator is safest modern BAL?

DMPS