Toxicology: Heavy Metals and Chelators Flashcards
found in:
* Storage batteries, ammunition,
* metal alloys, solder, glass,
* plastics, pigments and
* ceramics
Lead
TRUE OR FALSE: Lead has no useful purpose in the human body
true
lead is absorbed ____ but consistently via the _____ and _____
slowly; respiratory and gastrointestinal tract
how much lead is absorbed in children
50%
how much lead is absorbed in adults
10-15%
TRUE OR FALSE: Lead has poor absorption in the skin
true
Lead is ___% bound to RBCs, ___% free in
plasma
99% bound to RBCs, 1% free in
plasma
Lead is distributed through the ____
bone marrow, brain, kidney, liver, muscle and gonads; then bones
TRUE OR FALSE: Lead crosses the pancreas
false, placenta
half life of lead
1-2 months
Half life of lead in bones
years to decades
how much lead is excreted in urine
70%
Lead and arsenic inhibits ____
enzymatic function
what cations does lead interfere
calcium, zinc, iron
causes Oxidative stress generation
Lead and Arsenic
causes Gene expression changes
Lead and Arsenic
causes Cell signaling alteration
Lead and Arsenic
causes Disruption of membrane integrity
Lead and Arsenic
TRUE OR FALSE: Lead causes low bp
False, high bp
what are the Major Forms of Lead Intoxication
Inorganic Lead Poisoning and Organolead Poisoning
what kind of lead (organic/inorganic) travels through skin, GI, and respiratory
organic, inorganic is GI and respiratory only
major findings in organic lead
Encephalopathy
what kind of lead (organic/inorganic) has clinical findings of CNS deficits; peripheral neuropathy; anemia; nephropathy; hypertension; reproductive toxicity
inorganic
what kind of lead (organic/inorganic) Inhibits enzymes; interferes with essential
cations; alters membrane structures
inorganic
inorganic lead metabolize and eliminate in ___
Renal (major); feces
and breast milk (minor)
organic lead metabolize and eliminate in ___
Urine and feces (major);
Sweat (minor)
treatment for lead and arsenic
chelation therapy
what is chelation therapy medium, dose, and duration for lead poisoning
Intravenous edetate calcium disodium (CaNa 2 EDTA) at a dosage of 30-50mg/kg/d by continuous infusion for up to 5 days only
Oral Succimer (DMSA) is given after __ days
5 days
Retained lead objects require ___
gastrointestinal decontamination
Semiconductors, wood preservatives, nonferrous alloys, glass and turf herbicide
monosodium methane arsonate (MSMA)
Arsenic
arsenic is absorbed in ___
respiratory and GIT
TRUE OR FALSE: percutaneous absorption of lead is limited
false, arsenic
____ is Metabolized by the liver
via methylation reactions
Arsenic
where is arsenic excreted
Excreted in the Urine
(major), sweat and feces
distribution of arsenic
Predominantly soft tissues (highest in liver and kidney). Tightly bound to skin, hair and nails
TRUE OR FALSE: arsenic causes encephalopathy
true
Metabolism and Elimination of arsenic
Methylation; Excreted via Urine (major), Sweat and Feces (minor)
Hyperpigmentation and hyperkeratosis involving hands and feet
Usually due to chronic inorganic arsenic
poisoning
Raindrop pattern”
what is chelation therapy medium, dose, and duration for acute arsenic poisoning
Chelation with Unithiol 3 5mg/kg every 4-6 hours or Dimercaprol every 4-6 hours
Quicksilver or liquid metal
Mercury
found in Electrolytic production of chlorine
and caustic soda; electrical equipment, thermometer, instruments, fluorescent lamps; dental amalgams; artisanal gold
production
Mercury
Absorbed from the lungs, GI tract, and percutaneous route
Mercury
where is mercury most concentrated
kidneys
mercury is excreted via
urine and feces
major routes of elemental mercury
Respiratory tract
major routes of inorganic mercury
GI, skin (minor)
major routes of organic mercury
GI, skin, respiratory tract (minor)
