Medical Toxicology II

jmanderson's version from 2016-03-14 01:13



Question Answer
MOA of organophosphates?acetylcholinesterase inhibitors (via phosphorylation); ACh accumulation; IRREVERSIBLE
Organophosphate toxicity clinical featuresSalivation, lacrimation, urination, increased GI motility, vomiting, miosis, muscle fasciculations, paralysis, chronic neuropathy, bronchoconstriction
residual effect of organophosphate (1-3 days)intermediate syndrome
residual effect of organophosphate (1-7 days)extrapyramidal symptoms
residual effect of organophosphate (wks to years)neuropsychiatric effects
residual effect of organophosphate (1-5 wks, may be permanent)delayed chronic neuropathy (phosphorylation of neuropathy target esterase)
antidote for organophosphate toxicityATROPINE (large doses blocks ACh receptors), 2-PAM
is the cholinergic effect of carbamate reversible or irreversible?reversible
carbamate toxicity clinical featuresSalivation, lacrimation, urination, increased GI motility, vomiting, miosis, muscle fasciculations
antidote for carbamate toxicityATROPINE
what is the toxidrome of pestides?CHOLINERGIC (small pupils, wet skin)

metals 1


Question Answer
the antidote for acute intoxication of metals by bind to them to prevent toxic reactions, they are called ……… agentschelating agents
common current source of lead exposure?PLUMBING
what is the physiological role of lead?NONE (Any amount of lead can have adverse effects on the developing CNS)
acute inorganic lead toxicity clinical featuresAbdominal pain, hypertension, seizures, muscle weakness, metallic taste, anorexia, ENCEPHALOPATHY, delayed motor neuropathy, changes in renal and reproductive function
chronic inorganic lead toxicity clinical features in KIDS!!!!Growth retardation, neurocognitive deficits and developmental delay!!!
chronic inorganic lead toxicity clinical features in ADULTSanorexia, fatigue, malaise, HEADACHE, irritability, depression, ABDOMINAL PAIN, myalgias and ANEMIA
inorganic lead toxicity antidoteSuccimer – oral; Ethylenedinitrilotetraacetic Acid (EDTA) or EDTA with dimercaprol – IV
organ toxicity of LEAD in KIDSCNS toxicity => decreases: intelligence, memory, attention, fine motor skills; learning disabilities, increased aggression and antisocial behavior
tetraethyl lead toxicity clinical featuresHallucinations, headache, irritability, convulsions and coma
tetraethyl lead toxicity antidoteDecontamination and seizure control
treatment of lead toxicity besides antidotes?REMOVE FROM EXPOSURE
acute arsenic toxicity clinical featuresSevere gastrointestinal discomfort, vomiting, “rice-water” stools, capillary damage with dehydration and shock
chronic arsenic toxicity clinical featuresSkin changes, hair loss, bone marrow depression, anemia, chronic nausea
arsenic toxicity antidoteDIMERCAPROL (British anti-Lewisite), succimer (oral version)
dimecaprol (chelating agent) AEshypertension, tachycardia, N&V lacrimation , salivation, fever, thrombocytopenia and REDISTRIBUTION TO CNS
what heavy metal binds to thiols on enzymes and competes for phosphate binding in biological processes and is a known CARCINOGEN?arsenic

metals 2


Question Answer
acute copper toxicity clinical featuresVomiting, hematemesis, black stools, hypotension
chronic copper toxicity clinical featuresWILSON’S DISEASE, neuropsychiatric disorders, liver disease and KASYER-FEISCHER RINGS (Cu deposits in the eyes)
what is Cu deposits in the eye in Wilson’s disease called?KAYSER-FLEISCHER RINGS
what disease results in copper retention and impaired excretion which may result in copper toxicity?WILSON’S DISEASE
mechanism of Cu toxicitycan generate reactive oxygen species (ROS)
copper toxicity antidotePENICILLAMINE
contraindication to penicillaminePCN allergy
acute mercury toxicity clinical featuresChest pain, SOB, nausea, vomiting, kidney damage, gastroenteritis and CNS damage (neuropsychiatric disturbance - MAD AS A HATTER)
chronic mercury toxicity clinical featuresGINGIVOSTOMATITIS, colitis, fine hand TREMOR, ERETHISM (fits of crying, irrational behavior) and nephrotic syndrome
mercury toxicity antidoteSuccimer – oral; Unithiol – IV or oral
what food should pregnant females avoid due to potential mercury toxicity?seafood
iron toxicity clinical featuresBLOODY VOMIT AND DIARRHEA, coma, radiopaque material in gut (seen on x-ray), high leukocyte count, hyperglycemia, NECROTIZING GASTROENTERITIS
iron toxicity antidoteDEFEROXAMINE (chelating agent)
deferoxamine AEsorange-red urine, hypotension, flushing, abdominal discomfort and rash, ARDS if admin > 24 hours
………….. may occur with administration of deferoxamine > 24 hoursAcute respiratory distress syndrome (ARDS)



Question Answer
methanol mechanism of toxicity?Toxic metabolites: FORMIC ACID and formaldehyde lead to metabolic acidosis, coma and BLINDNESS
methanol toxicity clinical featuresRapid respiration, visual symptoms (BLINDNESS), osmolar gap, severe metabolic acidosis
methanol toxicity antidoteethanol, fomepizole (inhibits ALCOHOL DEHYDROGENASE)
with methanol toxicity, you may smell; ....... on the breathformaldehyde
how are people exposed to methanol?Solvents, denatured alcohol and windshield washer fluid; Misguided attempt of drinking methanol as an ethanol substitute
how does fomepizole and ethonal work to treat toxicity of methanol and ethylene glycol?Inhibit ALCOHOL DEHYDROGENASE to prevent the formation of toxic metabolites
sources of ethylene glycolantifreeze, drank as ethanol substitute or attempted suicide
mechanism of ethylene glycol toxicityHippuric, oxalic and glycolic acids cause metabolic acidosis and coma; Oxalic acid and glycolic acid lead to RENAL FAILURE
ethylene glycol toxicity clinical featuresRENAL FAILURE, CRYSTALS in urine, increased anion and osmolar gap, initial CNS excitation, normal eye examination, metabolic acidosis (glycolic acid, hippuric acid, oxalic acid)
ethylene glycol toxicity antidoteethanol, fomepizole



Question Answer
What toxidrome? high BP, P, RR, T; dilated pupils, wet skin (ex – cocaine)sympathomimetic
What toxidrome? high P, T; dilated pupils, dry skin (ex – atropine)anticholinergic
What toxidrome? small pupils, wet skin (ex – pesticides)cholinergic
What toxidrome? low BP, P, RR, T; small pupils (ex – morphine)opiates
What toxidrome? low BP, P, RR, T; variable pupils (ex – lorazepam)sedatives

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