Clinical Toxicology and Toxidromes Flashcards
what detoxifies acetaminophen
glutathione
this led by CYP450s may lead to products with more or less potential for toxicity
biotransformation
_____ may be a locus of detoxification or bioactivation
absorption
_____ often determines site of toxicity
distribution
promotion of this can be a therapeutic strategy
elimination of toxin
what age group has highest incidence of acute poisoning
1-2 yr olds
most common reason for poisoning by kids
unintentional
most common reason for poisoning by adults
intentional- suicide
this age group deals with analgesics and sedatives as poison
adults
this age group uses household cleaning supplies and cosmetics as poison
children
the opiate epidemic (what yr did all drugs increase in consumption)
2014
drug to administer if suspected fentanyl overdose
naloxone
highest prevalence of drug overdose
fentanyl and related drugs
what 2 things are the leading cause of pediatric accidental poisoning fatalities
iron and pesticides
this toxicity deals with the drug’s normal pharmacology, but just too high of dose/amount
pharmacologic toxicity
ex. metoprolol toxicity=heart block
pharmacologic toxicity
type of toxicity where our body is producing an effect that the drug is not made to do by itself (ex. acetaminophen-fever/ibuprofen-hives)
pathological toxicity
ex. of genotoxicity
radiation; cancer agents
ex. of drug-drug interactions that can lead to toxicity
inhibition or induction of CYP450
abnormal reactivity to a chemical peculiar to a given individual (ex. anaphylaxis from giving drug)
idiosyncratic drug rxns
final common effect of many toxins that is done by apoptosis or necrosis
cell death
3 main steps to manage a poisoned patient:
- monitor vital signs (O2, fluids);ABC’s
- obtain history (what they were doing to bring them in here)
- perform toxicologically-oriented patient exam
tx of this is support vital functions, slow drug absorption, and promote excretion
poison management
one way to get rid of toxin by absorption in GI tract is____ and combine it with _____ to make them excrete it
activated charcoal; sorbitol
this chemical can lead to urinary excretion of toxin
sodium bicarbonate
2 main antidotes to administer for opiate intoxication
naloxone (Narcan)
naltrexone (trexan)
antidote used for acetaminophen poisoning
N-acetylcysteine
antidote for atropine toxicity (can cross BBB)
physostigmine
antidote for methanol poisoning
ethanol
antidote for organophosphate poisoning
atropine and pralidoxime
antidote for metal poisoning (lead and iron)
metal chelators
a constellation of clinical signs that may suggest a particular type of ingestion
toxidrome
anticholinergic
cholinergic
sympathomimetic
sedative
hallucinogenic
serotonergic
toxidromes
acute ingestion of acetaminophen happens with what dose in children
> 200mg/kg
acute ingestion of acetaminophen happens with what dose in adults
6-7 g
N/V and anorexia are main presentations for what toxicity
acute acetaminophen toxicity
after 1-2 days, what levels rise that lead to liver necrosis and also acute renal failure can happen
AST and ALT
presents with N/V and worsening sx’s and evidence of hepatic injury
chronic acetaminophen toxicity
how to dx acetaminophen toxicity:
at 4 hours after ingestion, obtain blood work (CMP)
how to tx acetaminophen toxicity
N-acetylcysteine (NAC)
activated charcoal/sorbitol
fluids; vitamin C
this toxicity is caused by GSH (glutathione) depletion
acetaminophen
this toxicity presents with vomiting, tinnitus, and ABG’s show respiratory alkalemia and metabolic acidosis
acute salicylate toxicity
this toxicity presents with confused elderly patient and its harder to diagnose
chronic salicylate toxicity
how to dx salicylate toxicity:
check serum salicylate toxicity
check ABG’s (reveal respiratory alkalemia and metabolic acidosis)
how to tx salicylate toxicity:
get them to ICU
sodium bicarbonate
activated charcoal
exposure for iron toxicity
prenatal vitamins
mechanism that causes iron toxicity
ROS stress
presents w/ abd pain, vomiting and long term GI issues
iron toxicity
to dx iron toxicity:
serum iron and ferritin levels
exposure hx
to tx iron toxicity:
deferoxamine (metal chelators)
exposure for lead toxicity:
paint
mechanism for lead toxicity:
binds SH groups and inhibits other enzymes
this toxicity is multi-system; N/V/ abd pain, peripheral neuropathy, chronic encephalopathy
lead toxicity
to dx lead toxicity:
exposure hx
blood lead level
tx lead toxicity:
metal chelators (EDTA, dimercaprol)
what meds are used for bronchospasms/problems with breathing due to lung inflammation from gases, vapors, smoke inhalation (CO, ozone)
steroids (albuterol)
what is the treatment for cocaine toxicity
Labetalol: alpha and beta adrenergic blocker
this drug is an anticoagulant
warfarin
antidote for warfarin toxicity
Vitamin K1 (Phytonadione) “fight to not die-one”
inhibits Vitamin K action and is used in rodentocide to kill rodents
warfarin
progressive hypoxia leading to HA/V , syncope, seizures, coma
Carbon Monoxide toxicity
what do you treat carbamate poisoning with? (organophosphate poisoning)
Atropine, NOT pralidoxime
S-warfarin is a substrate for which enzyme
CYP2C9
R-Warfarin is a substrate for which enzyme
CYP3A4
S-Warfarin + cimetidine =
bleeding (cimetidine inhibits CYP2C9)
R-Warfarin + erythromycin =
bleeding (erythromycin inhibits CYP3A4)
this toxidrome includes: sleepiness/coma, decrease in HR, RR, and pupil diameter
opioid toxicity
basically this molecule binds Hb tightly, not allowing it to bind to O2
CO poisoning
this poisoning leads to agitation, increased HR, BP, temperature, and dilated pupils, even twitching
amphetamine poisoning
drug development phase that is used first in human volunteers
phase I
drug development phase that is used in patients (testing efficacy)
phase II
drug development phase that is a multi-site analysis (looking at different hospitals with patients who were administered drug); deals with dosing of drug
phase III
drug development phase that deals with after drug is approved (post marketing analysis)
phase IV
which 2 phases used for antineoplastic drugs
I and II
this drug has financial and operational incentive to be developed faster so that patients can get treatment (newer tx receiving more funding for research)
orphan drug
term used for not just 1 drug being taken by a patient but many; think meth
SPEED BALL
this age group has the highest incidental poisoning (accidental)
1-2 yr olds
this age group when poisoned are most likely to die
adults
the amount of a drug needed to produce an effective outcome 50% of the time
ED50
this poisoning is another organophosphate poisoning and we treat pt. with atropine and pralidoxime
Parathion poisoning
how do you know if you are giving correct amount of atropine?
lungs clear on auscult
BP systolic >80
HR>80
the concentration of ligand required to occupy 50% of binding sites (measure of binding affinity)
Kd
how well a drug can activate full response on receptor
kx (effect)
this antagonist lessens function of enzyme(receptor) and decreases max response and shifts ED50 to the right
allosteric antagonist
decrease in the maximum response (b/c # of agonist binding sites decrease
non-competitive antagonists (pseudo-irreversible antagonist
measure of binding affinity b/t antagonist and receptor
Ki
competes with primary agonist just shifts ED50 to the right (tries to overcome by increasing conc. of agonist)
competitive antagonist
decreases the response of the receptor from its baseline (level of activity) all by itself
inverse agonist
shifts curve to left and makes agonist more potent; binds to a distinct site (not same site as ligand)
allosteric agonist
binds to same site as ligand and activates receptor
primary agonist