B5-093 Toxicology Flashcards
most common cause of acute liver failure in the Western world
acetaminophen
causes hepatic necrosis secondary to cascade of signaling events, resulting in mitochondrial injury and cell death
acetaminophen
standard of care for acetaminophen overdose
NAC within 8-12 hours of exposure
dose based on nomogram, shows acetaminophen plasma levels
- causes tinnitus, dizziness
- eventually causes metabolic acidosis, hyperpyrexia
- can cause coma, convulsions, respiratory failure
salicylate
treatment for salicylate overdose
sodium bicarbonate to alkalize urine to promote excretion, counteracts acidosis
cause tachycardia, hypertension, seizures, mydriasis
sympathomimetics
cocaine, amephetamines
cocaine and amphetamines fall under what classification?
sympathomimetics
treatment for sympathomimetics overdose
maintain airway and respiration
* control convulsions: IV diazepam
* if convulsions interfere with respiration: succinylcholine
* vasopressors
* if orally ingested, charcoal emesis to remove
what are contraindicated in the treatment of sympathomimetics overdose?
beta blockers
worsen toxicity
cause unconsciousness, miosis, slow/shallow respirations
opioids
opioid triad
morphine, fentanyl, tramedol fall under what classification?
opioids
treatment for opioid overdose
naloxone
short DOA, give repeat doses
- have anti-cholinergic effects
- cause cardiovascular toxicity
- blockade of myocardial fast sodium channels causes QT prolongation, hypotensions
- seizures
tricyclic antidepressants (amitryptiline)
anticholinergic effects
dry mouth
tachycardia
nausea
confusion
urine retention
treatment for tricyclic anti-depressant overdose
sodium bicarbonate to maintain arterial pH, reversing cardiac depressant effects
what class of drugs in contraindicated in the treatment of tricyclic antidepressant overdose?
class IA anti-arrthymics
quinidine, procainamide, lidocaine, etc
- cause first degree heart block, hypotension, and bradycardia
- increased PR intervals
- hypoglycemia and hyperkalemia
- CNS toxicity
beta blockers
treatment for beta blocker overdose
- glucagon for bradycardia/hypotension
- sodium bicarb for conduction defects
causes torsade de pointes polymorphous V tach w/ QT prolongation
sotalol overdose
treatment for sotalol overdose
- isoproternol IV
- magnesium
cause AMS, fever, agitation, myclonus, hyperreflexia, ataxia, diaphoresis
serotonin syndrome
drugs that can cause serotonin syndrome
5
SSRIs
MAOIs
TCAs
Amphetamines
Opioids
usually SSRI + one of the others
treatment for serotonin syndrome
- serotonin antagonists (cyproheptadine, propranolol)
- dantrolene
organophosphates are […]
reversible/irreversible
irreversible
carbamates are […]
reversible/irreversible
reversible
parathion (paraoxon)
malathion (malaoxon)
sarin
soman
belong to what classification?
organophosphates
cholinesterase-inhibiting insecticides
carbaryl
aldicarb
carbofuran
aminocarb
belong to what classification?
carbamates
cholinesterase-inhibiting insecticides
cause salivation, lacrimation, urination, defecation
cholinesterase-inhibiting insecticides
SLUD
cholinesterase-inhibiting insecticides overdose treatment
- atropine - blocks cholinergic effects
- 2-pralidoxime (2-PAM) - reactivates ACHase enzyme
2-PAM for organophosphates only
2-PAM is contraindicated for […] toxicity
carbamate
chemicals affecting heme
- methemoglobin inducing agents (nitrates)
- carbon monoxide
- cyanide
- causes hypertension, hypoxia, and cyanosis
- chocolate colored blood
nitrate induced methemoglobin
treatment for nitrate induced methemoglobin
methylene blue
will convert methemoglobin back to hemoglobin
odorless and colorless gas that is a major cause of lethal poisoning in US
carbon monoxide
carboxyhemoglobin cannot transport
oxygen
- causes headaches, dizziness, stupor, progressive brain anoxia
- bright red mucous membranes
carbon monoxide
carboxyhemoglobin is cherry red
treatment for carbon monoxide poisoning
oxygen
complexes with ferric iron of cytochrome oxidase inhibiting oxygen use in mitochondria
cyanide
causes dizziness, headache, hypotension, unconciousness, respiratory failure
cyanide
treatment for cyanide poisoning
- induce methemoglobin via nitrates (high affinity for cyanide ions)
- hydroxocobalamin: binds to cyanide ions to excrete in urine
metals causing toxicity
5
- arsenic
- lead
- mercury
- cadmium
- manganese
causes hemolysis, hemoglobinurea, GI disturbances, ventricular arrhythmias, vasodilation, rosy complexion
acute arsenic poisoining
causes nephritis, dermatitis, cancer of bladder/liver
chronic arsenic toxicity
binds to sulfahydryls, especially in lipoic acid, interfering with energy production
arsenic
preferred chelator for acute arsenic poisoning
dimercaprol
preferred chelator for chronic arsenic poisoning
succimer
most exposure comes from smoke, smog, or old paint
lead
causes kidney damage and GI irritation
acute lead poisoning
causes plumbism, microcytic anemia, constipation, abdominal pain, neurological damage
chronic lead poisoning
causes developmental deficits, low IQ, growth retardation, irritability in children
lead poisoning
causes hypertension, cholic, anemia in adults
lead poisoning
treatment for lead poisoning
chelation therapy:
* CaNa2EDTA
* BAL
* penicillamine (oral)
* succimer (oral)
kids should be treated for lead poisoning at what blood lead level?
greater than 5 ug/dl