Metals Flashcards
Nickel
human resp tract carcinogen; contact dermatitis is common
Metallic nickel combines with carbon monoxide to form nickel carbonyl
Klaassen, Curtis D.. Casarett & Doull’s Toxicology: The Basic Science of Poisons, 9th Edition (p. 1130). McGraw-Hill Education. Kindle Edition.
Lead
Children are most sensitive to effects in the central nervous system, whereas peripheral neuropathy, chronic nephropathy, and hypertension are concerns in adults.
Peripheral neuropathy is a classic manifestation of lead toxicity in adults. Footdrop and wristdrop. segmental demyelination and possibly axonal degeneration.
The most sensitive effects of lead are the inhibition of δ-aminolevulinic acid dehydratase (ALAD) and ferrochelatase.
mimics Ca2+
Klaassen, Curtis D.; Watkins, John B.. Casarett & Doull’s Essentials of Toxicology, Third Edition (Lange) . McGraw-Hill Education. Kindle Edition.
Lithium
neuromuscular changes, seizures, slurred speech, renal damage, arrhythmia, hypertension, goiter
treated with diuretics (e.g. amiloride)
Arsenic
smelting, pesticides, herbicides
skin. concentrates in hair and nails; urinary levels are best indicator of exposure.
impairs oxidative phosphorylation
acute - CV failure, sensory loss, hematopoietic effects (granulocytopenia)
chronic - neurotox, peripheral neuropathy, liver injury, vascular disease, hyperpigmentation/hyperkeratosis
teratogenic in animals
carcinogenic in humans; not animals; skin (oral) and lung (occup). not a mutagen in bacteria
many metabolites are methylated
enterohepatic recirculation
Metals that provoke immune reactions
mercury, gold, platinum, beryllium, chromium, and nickel.
Klaassen, Curtis D.; Watkins, John B.. Casarett & Doull’s Essentials of Toxicology, Third Edition (Lange) . McGraw-Hill Education. Kindle Edition.
iron overdose
Acute iron poisoning from accidental ingestion of iron-containing dietary supplements is the most common cause of acute toxicity.
Symptoms include abdominal pain, diarrhea, and vomiting. Of particular concern are pallor, metabolic acidosis, liver damage, and cardiac collapse.
Desferrioxamine is chelator of choice for Tx
Hereditary hemochromatosis is an insufficiency of hepcidin (increased risk for hepatocellular carcinoma)
Klaassen, Curtis D.. Casarett & Doull’s Toxicology: The Basic Science of Poisons, 9th Edition (p. 1134). McGraw-Hill Education. Kindle Edition.
Beryllium
lung - chemical pneumonitis, hypersensitivity, chronic granulomatous pulmonary disease
contact dermatitis
coal combustion
initially high doses to liver, but then bone
carcinogenic in humans - lung
Thallium
one of the most toxic metals
toxic effects may result from interference with the biological functions of potassium.
absorbed through the skin and gastrointestinal tract.
Prussian blue, the most commonly used antidote,
The triad of gastroenteritis, polyneuropathy, and alopecia is regarded as the classic syndrome of thallium poisoning
Klaassen, Curtis D.. Casarett & Doull’s Toxicology: The Basic Science of Poisons, 9th Edition (p. 1147). McGraw-Hill Education. Kindle Edition.
Mercury
inorganic - kidney
organic - brain
nonspecific cell injury and death due to binding to enzyme systems
The kidneys are the primary target organs for accumulation of Hg2+, and the S3 segment of the proximal tubule is the initial site of toxicity,
chronic low exposure - immunologic glomerular disease
methyl mercury is most important
Acrodynia has occurred in children chronically exposed to inorganic mercury compounds in teething powder and diaper disinfectants, as well as to organomercurials.
mercury vapor - tremors, gingivitis, erethism
reabsorbed from bile
crosses BBB by combining with cystein and resembling methionine
Klaassen, Curtis D.. Casarett & Doull’s Toxicology: The Basic Science of Poisons, 9th Edition (p. 1129). McGraw-Hill Education. Kindle Edition.
Cadmium
dietary, especially shellfish; plants; cigarette smokers
resp absorption>GI; absorption increased by deficiencies in calcium, iron, protein
welding, battery, paints, electroplating; cigarette smoke
acute - nausea, abdominal pain, pneumonitis, pulmonary edema
chronic - COPD, emphysema, chronic renal tubular dz
hypercalciuria, renal stone formation, osteomalacia, and osteoporosis; Itai-Itai
accumulates in liver and kidney (metallothionein)
possible human lung carcinogen; possibly prostate
copper tox treatment
Penicillamine
also useful for lead, mercury, and iron
Garlic breath
Selenium, tellurium, arsenic, thallium
