Environmental Toxins Flashcards
- irreversible
- parathion, malathion
- sarin, soman (nerve agents)
organophosphates, irreversible cholinesterase inhibitors
- carbaryl, aldicarb, carbofuran, aminocarb
- 2PAM contraindicated
carbamates, cholinesterase inhibitors
- salivation, lacrimation, urination, defecation
- diarrhea, pinpoint pupils, resp difficulty, pulm edema, cyanosis
- usually die from drowning in secretions
cholinesterase inhibitor insecticide poisoning
- give small dose of atropine to block cholinergic effect
- 2PAM prior to aging
- support vitals
tx for cholinesterase inhibiting enzymes
- free radicals –> lipid peroxidation in lungs
- tx is supportive
paraquat (herbicide)
- carabon tetrachloride, chloroform, methylene chloride
- Cyp2E1 to CCl3 –> free radical in liver, lipid peroxidation –> calcium release –> hepatotoxic
- tx supportive
halogenated hydrocarbons
- kerosone, diesel fueal, white spirit, polishes
- pulmonary irritation with inhalation, CNS depression, can see severe pneumonitis after aspiration of liquid
- tx: emesis, lavage w/o tracheal intubation contraindicated
aliphatic hydrocarbons
- CNS stimulation early at low doses, then depression
- liver and kidney damage at high doses
- arrythmias enhanced, aplastic anemia and leukemia with long term exposure
aromatic hydrocarbons (benzene, toluene, xylene)
- local irritation and corrosion of GI tract
- muscle weakness, convulsions and collapse due to calcium chelation
- renal tubular damage due to calcium oxalate precipitation
- tx: antidote is calcium gluconate IV, oral calcium, force fluids to prevent deposition in tubules
corrosives (oxalic acids, oxalates, bleaches, metal cleaners, rust removers)
- GI irritation and necrosis, massive hemorrhage and hypovolemic shock
- dilute acid with water, milk of magnesia
corrosives (mineral acids, Hcl, sulfuric)
- irritation, inflammation, tissue damage
- more penetrating than strong acids, death due to hypovolemic shock
- dilute with water
corrosive (strong alkali, hydroxides)
-soaps, cleansers, drain cleaner
- oxidize hemoglobin (fe2+) to methemoglobin Fe3+ incapable of carrying oxygen
- chocolate colored blood, hypotension, hypoxia, cyanosis, convulsions
- only treat when 35% of Hb oxidized, use methylene blue to reduce back to hemoglobin
nitrites, aminophenols
- odorless and colorless gas
- much greater affinity than oxygen for hemoglobin, can’t transport oxygen
- left shift: impairs ability of oxyhemoglobin to give up its oxygen to peripheral tissues
- cherry red blood, HA, dizzy, stupor d/t brain anoxia
- admin oxygen, hyperbaric if severe
carbon monoxide poisioning
- colorless gas, smells like almonds
- inhibits cytochrome oxidase in mitochondria
- dizzy, headache, hypotension, unconsciousness, convulsions, respiratory failure
- rapid tx with hydroxycobalamin, give sodium thiosulfate
- old treatment: induce methemoglobinemia by admin of sodium nitrite in combo with sodium thiosulfate
cyanide poisoning
- primary: dyspnea and discomfort
- weakness, respiratory impairment
- total disability, expirations prolonged and difficult, predisposition to TB, die of right heart failure
- carcinogen
- tx supportive
free crystalline silica (sand at construction site)
- linear fibrosis in lungs, pleural adhesions and calcifications
- tumor after moderate exposure
- dyspnea, resp impairment, bronchogenic carcinoma and pleural mesothelioma
asbestos
- bind to sulfhydryl groups on enzymes, interfere with cell metabolism
- AsH3 most toxic
- As5+ blocks ATP
- As3+ binds sulfhydryl groups in lipoic acid interfers with energy production
- acute: hemolysis and hemoglobinuria
- chronic: dermatitis, mees lines on nails, cirrhosis, polyneuritis, cancer
- dimercapor is chelator for acute
- succimer for chronic
arsenic and arsine
- accumulates in body, stored in bones and nervous system
- acute inorganic toxicity –> GI irritation, kidney damage
- acute organic poisoning –> CNS
- chronic inorganic –> plumbism, lead lines on gum, basophilic erythrocyte stippling, accumulation of d-ALA –> microcytic anemia
- CNS effects more prominent in children, decreased IQ, hyperirritability, behavior distrubance
- neuromuscular effects, wrist/ankle drop due to degneration of peripheral nerves
- tx: at 5mcg/dL, metal chelators (cana2edta IV, dimercaprol, penicillamine, succimer)
lead poisoning
- all inorganic is toxic, acute: GI symptoms
- metallic: volatile, acute chemical pneumonitis, noncardiogenic pulm edema
- inorganic: acute tubular necrosis, shock, diarrhea
- delayed: severe kidney damage, GI hemorrhage
mercury poisoning
- early: salivation, stomatitis
- late: erethism, uncontrollable blushing, emotional instability, tremor
- hallucinations, tremor
chronic mercury exposure
organic: parasthesia, muscle twitching, ataxia
mercury
in tobacco –> kdiney, lung, CV, immune
-carcinogen, no chelator
cadmium
Parkinsons like syndrome, no chelator
manganese
treatment for lead and zinc poisoning?
Ca Na2EDTA
used to chelate arsenic, lead, gold, inorganic mercury. can see CNS disturbance
dimercaprol
chelates copper (good for Wilson’s), RA, given orally, don’t give in renal insufficiency
penicillamine
given orally for lead poisoning in kids with >45 mcg/dL
succimer
used for iron, can induce shock with rapid infusion, long term therapy leads to ocular damage
deferoxamine
