inservice review: toxicology gerry maloney, do attending physician, emergency medicine and medical...

Inservice Review: Inservice Review: ToxicologyToxicologyGerry Maloney, DOGerry Maloney, DO

Attending Physician, Emergency Attending Physician, Emergency Medicine and Medical ToxicologyMedicine and Medical Toxicology

CWRU/MetroHealth Medical CenterCWRU/MetroHealth Medical Center

AnalgesicsAnalgesics• APAPAPAP

• 140 mg/kg toxic dose for 140 mg/kg toxic dose for single acute ingestion single acute ingestion (200 mg/kg peds)(200 mg/kg peds)

• Rumack-Mathews Rumack-Mathews nomogram nomogram only only for single for single acute ingestionacute ingestion

• NAC can be given with NAC can be given with charcoal (no need to charcoal (no need to adjust dose)adjust dose)

• PO NAC: 140 mg/kg load, PO NAC: 140 mg/kg load, then 70 mg/kg q 4 h for 72 then 70 mg/kg q 4 h for 72 hh

• IV NAC: 150 mg/kg LD, IV NAC: 150 mg/kg LD, then 50 mg/kg over 4 h, then 50 mg/kg over 4 h, then 100 mg /kg over 16 hthen 100 mg /kg over 16 h

• APAPAPAP• Liver injury usually takes Liver injury usually takes

24 h to develop for 24 h to develop for acute ODacute OD

• Elevated AST & Elevated AST & detectable APAPdetectable APAP treat treat with NACwith NAC

• Refer for transfer: Refer for transfer: elevated INR, elevated INR, encephalopathy, encephalopathy, acidosis, renal failureacidosis, renal failure

AnalgesicsAnalgesics

• ASAASA• Toxic dose 140 mg/kgToxic dose 140 mg/kg• See respiratory alkalosis See respiratory alkalosis firstfirst, then , then

mixed metabolic acidosis/resp alkalosismixed metabolic acidosis/resp alkalosis• Cause of AGMACause of AGMA• Treatment is IV bicarbTreatment is IV bicarb• HD for: level > 60 chronic or > 90 HD for: level > 60 chronic or > 90

acute, esp if mental status changesacute, esp if mental status changes

OpiatesOpiates

• Heroin: short-actingHeroin: short-acting• Methadone: long-actingMethadone: long-acting• Narcan: lasts approx 25-45 minNarcan: lasts approx 25-45 min• Can see seizures from Can see seizures from

demerol/propoxyphenedemerol/propoxyphene• Wide QRS and hypotension with Wide QRS and hypotension with

propoxyphenepropoxyphene• Pulmonary edema can be seen with allPulmonary edema can be seen with all

AlcoholsAlcohols• EtOH: zero-order kineticsEtOH: zero-order kinetics• IsoOH: osmole gap, may be serum/urine ketones, IsoOH: osmole gap, may be serum/urine ketones,

gastritis, gastritis, no no metabolic acidosismetabolic acidosis• MeOH: blindness, severe acidosis; windshield-washer MeOH: blindness, severe acidosis; windshield-washer

fluidfluid• Ethylene Glycol: antifreeze; Ca Ox crystals in urine, Ethylene Glycol: antifreeze; Ca Ox crystals in urine,

flourescent urine; renal failure, metabolic acidosisflourescent urine; renal failure, metabolic acidosis• If double gap (osmole and anion) is present, think MeOH If double gap (osmole and anion) is present, think MeOH

or EGor EG• MeOH/EG treated with IV EtOH or fomepizole; MeOH/EG treated with IV EtOH or fomepizole;

hemodialysis for acidosis, levels > 25 mg/dLhemodialysis for acidosis, levels > 25 mg/dL• Anion: Na-Cl + HCO3; Osmole: 2(Na) + BUN/2.8 + Anion: Na-Cl + HCO3; Osmole: 2(Na) + BUN/2.8 +

Glu/18 + EtOH/4.6Glu/18 + EtOH/4.6

AnestheticsAnesthetics

• Know the dose and effects of your Know the dose and effects of your procedural sedation drugs (versed, procedural sedation drugs (versed, ketamine, fentanyl, propofol) and when ketamine, fentanyl, propofol) and when not to use themnot to use them

• Classic question is lidocaine allergic pt Classic question is lidocaine allergic pt who need local anesthesia; what can you who need local anesthesia; what can you use?use?• Lidocaine is an amide; amides have 2 i’sLidocaine is an amide; amides have 2 i’s• So look for the answer with one i, or can also So look for the answer with one i, or can also

use benadryluse benadryl

Autonomic AgentsAutonomic Agents

• Know cholinergic, anticholinergic, Know cholinergic, anticholinergic, sympathomimetic toxidromessympathomimetic toxidromes

• Cholinesterase inhibitors (OP agents, Cholinesterase inhibitors (OP agents, nerve agents)nerve agents)• Treatment is atropine 1Treatment is atropine 1stst (endpoint is (endpoint is

secretions, not heart rate or atropine dose)secretions, not heart rate or atropine dose)• Then 2-PAM (to prevent aging, ie Then 2-PAM (to prevent aging, ie

irreversible binding of OP to cholinesterase irreversible binding of OP to cholinesterase enzyme)enzyme)

• DUMBELS is mnemonicDUMBELS is mnemonic


• AnticholinergicAnticholinergic• Dry skin/mouth or decreased bowel Dry skin/mouth or decreased bowel

sound is cluesound is clue• Treatment is benzo first; can consider Treatment is benzo first; can consider

physostigmine (though NOT if tricyclic physostigmine (though NOT if tricyclic on board)on board)

• Jimson weed or benadryl are classic Jimson weed or benadryl are classic agentsagents


• SympathomimeticsSympathomimetics• HTN, tachy, dilated pupils, HTN, tachy, dilated pupils, moist moist skinskin• Cocaine can cause Na channel Cocaine can cause Na channel

blockade and wide QRSblockade and wide QRS• Treatment for all sympathomimetics is Treatment for all sympathomimetics is

lots of benzoslots of benzos• Avoid Avoid ββ blockers in cocaine blockers in cocaine• Ecstasy-see bruxism and hyponatremiaEcstasy-see bruxism and hyponatremia

Anticoagulants Anticoagulants

• Most children with rat poison Most children with rat poison (brodifacoum) asymptomatic(brodifacoum) asymptomatic

• FFP is first-line for severe bleedingFFP is first-line for severe bleeding• IV vitamin K is associated with IV vitamin K is associated with

allergic reactionsallergic reactions• Make sure you give K1 (activated Make sure you give K1 (activated

vit K)vit K)

Anticonvulsants Anticonvulsants

• DilantinDilantin• Iv infusion: hypotension (from Iv infusion: hypotension (from

propylene glycol) that is rate-related, propylene glycol) that is rate-related, necrosis if IV infiltratesnecrosis if IV infiltrates

• PO: OD sees ataxia/nystagmus, may PO: OD sees ataxia/nystagmus, may be obtunded latebe obtunded late

• Normal level is 10-20Normal level is 10-20• Load is 17 mg/kg IVLoad is 17 mg/kg IV

AnticonvulsantsAnticonvulsants

• CarbamazepineCarbamazepine• Level is 4-12Level is 4-12• Has active metabolite that is also toxic (10,11 epoxide)Has active metabolite that is also toxic (10,11 epoxide)• Can cause seizure in OD, cross react with TCA on urine Can cause seizure in OD, cross react with TCA on urine

toxtox• Treat with multi-dose ACTreat with multi-dose AC

• VPAVPA• Hyperammonemia in absence of toxic level or abnl LFTHyperammonemia in absence of toxic level or abnl LFT• Need serial levels in OD (irregular absoprtion)Need serial levels in OD (irregular absoprtion)• Normal is 50-100Normal is 50-100• Can use MDAC, hemodialysis (level >1000) or carnitineCan use MDAC, hemodialysis (level >1000) or carnitine

Antidepressants Antidepressants

• TCA: hypotension, seizure, anticholinergic TCA: hypotension, seizure, anticholinergic sx; wide QRS on EKG (look at aVR); treat sx; wide QRS on EKG (look at aVR); treat with bicarbwith bicarb

• QRS > 120 predicts increased risk of szrQRS > 120 predicts increased risk of szr• Trazodone: priapism, orthostatic Trazodone: priapism, orthostatic

hypotensionhypotension• Buproprion: wide QRS, seizure, SND Buproprion: wide QRS, seizure, SND

reuptakereuptake• Citalopram: cardiotoxicCitalopram: cardiotoxic• SSRI or MAOISSRI or MAOI think serotonin syndrome, think serotonin syndrome,

may be delayed if MAOI involvedmay be delayed if MAOI involved

Antipsychotics Antipsychotics

• Can see QT prolongation and orthostatic Can see QT prolongation and orthostatic hypotension with allhypotension with all

• EPS/akathisia decreased with use of EPS/akathisia decreased with use of benadryl/cogentinbenadryl/cogentin

• NMS vs SS: NMS has slow onset, lead pipe NMS vs SS: NMS has slow onset, lead pipe rigidity, hyperthermia; SS rapid onset, rigidity, hyperthermia; SS rapid onset, reflexes and muscle tone LE>UEreflexes and muscle tone LE>UE

• Stop offending agent, benzos, may consider Stop offending agent, benzos, may consider cyproheptadine (SS) or dantrolene (NMS)cyproheptadine (SS) or dantrolene (NMS)

COCO

• Know half life of CO (RA 3-4 h, Know half life of CO (RA 3-4 h, 100% 90 min, HBO 23 minutes)100% 90 min, HBO 23 minutes)

• Know classic presentation (HA, Know classic presentation (HA, vomiting, winter, whole family sick)vomiting, winter, whole family sick)

• Refer for HBO: level > 40% (15% if Refer for HBO: level > 40% (15% if pregnant), syncope, MI, mental pregnant), syncope, MI, mental status change, neuro deficitsstatus change, neuro deficits

• CNS lesion: bilat globus pallidusCNS lesion: bilat globus pallidus

Cardiac MedsCardiac Meds

• Digoxin Digoxin • Level > 2 ng potentially toxicLevel > 2 ng potentially toxic• Classic EKG is bidirectional VT or PAT Classic EKG is bidirectional VT or PAT

with blockwith block• Most common finding is PVC’sMost common finding is PVC’s

• K > 5 serious toxicityK > 5 serious toxicity• Digibind: empiric treatment is 5-10 vials Digibind: empiric treatment is 5-10 vials

(acute OD), 3-5 vials (chronic OD)(acute OD), 3-5 vials (chronic OD)• Can calculate if level is known (dig level x Can calculate if level is known (dig level x

wt in kg/100= # of vials)wt in kg/100= # of vials)

Cardiac MedsCardiac Meds

• Beta blockersBeta blockers• Glucagon is antidoteGlucagon is antidote• Propranolol causes seizuresPropranolol causes seizures

• CCBCCB• See metabolic acidosis and hyperglycemia (DKA like See metabolic acidosis and hyperglycemia (DKA like

picture)picture)• Most ER so need prolonged observationMost ER so need prolonged observation• ““pill can kill” in kidspill can kill” in kids• Treatment: calcium, pressors, HIETreatment: calcium, pressors, HIE

• ClonidineClonidine• Looks like opioid, narcan sometimes reverses effectsLooks like opioid, narcan sometimes reverses effects

CausticsCaustics

• No vomiting, no charcoalNo vomiting, no charcoal• Alkali: liquefactive necrosisAlkali: liquefactive necrosis

deeper burndeeper burn• Acid: coagulation necrosisAcid: coagulation necrosis stops stops

burnburn• Can have severe esophageal injury Can have severe esophageal injury

w/o intra-oral injuryw/o intra-oral injury• Steroids not generally helpfulSteroids not generally helpful

CN/HSCN/HS

• CN: rapid BP fluctuations, metabolic CN: rapid BP fluctuations, metabolic acidosis (elevated lactate)acidosis (elevated lactate)

• Affects Cytochrome aa3Affects Cytochrome aa3• Treatment: amyl nitrate/sodium nitrite, Treatment: amyl nitrate/sodium nitrite,

then sodium thiosulfatethen sodium thiosulfate• See “arterialization” of venous blood See “arterialization” of venous blood

(high venous O2 sat)(high venous O2 sat)• HS: rapid knockdown with rotten egg HS: rapid knockdown with rotten egg

smellsmell

MetalsMetals

• AC binds poorly to all metals (works for AC binds poorly to all metals (works for strychnine)strychnine)

• Li: causes ataxia; HD if level > 2.5 (chronic) or Li: causes ataxia; HD if level > 2.5 (chronic) or 4 (acute); can treat with IVF/WBI4 (acute); can treat with IVF/WBI

• As: see vomiting early, then neuropathy/multi-As: see vomiting early, then neuropathy/multi-organ failure/prolonged QT, Mee’s linesorgan failure/prolonged QT, Mee’s lines

• Lead: Lead: • level > 70 needs parenteral chelation. level > 70 needs parenteral chelation. • Give BAL and EDTA. Give BAL and EDTA. • Peanut allergy is contraindication to BAL. Peanut allergy is contraindication to BAL. • > 10 is action level> 10 is action level

Herbicides/pesticides/Herbicides/pesticides/

rodenticidesrodenticides

• Many are arsenicalMany are arsenical• Also see superwarfarins or Also see superwarfarins or

organophosphatesorganophosphates• Paraquat: need to decrease FiO2Paraquat: need to decrease FiO2

HydrocarbonsHydrocarbons

• Determinants of aspiration risk:Determinants of aspiration risk:• Surface tensionSurface tension• ViscosityViscosity• VolatilityVolatility

• Never induce vomitingNever induce vomiting• May see delayed pneumonitis (esp in kids)May see delayed pneumonitis (esp in kids)• Sniffers/huffersSniffers/huffersmyocardial sensitization myocardial sensitization

to catecholamines, can have sudden deathto catecholamines, can have sudden death

Hypoglycemics Hypoglycemics

• Insulin: not muchInsulin: not much• Sulfonylurea: prolonged Sulfonylurea: prolonged

hypoglycemia; octreotide is hypoglycemia; octreotide is antidoteantidote• May be delayed in kids, generally May be delayed in kids, generally

need 24 hour OBSneed 24 hour OBS

• Metformin: lactic acidosis, esp in Metformin: lactic acidosis, esp in renal failurerenal failure

Inhalational Inhalational

• Water solubility determines toxicityWater solubility determines toxicity• High-immediate irritation to eyes/MMHigh-immediate irritation to eyes/MM• Medium (like Cl) some upper and lower Medium (like Cl) some upper and lower

airway stuffairway stuff• Low: all the way into the lungs, Low: all the way into the lungs,

delayed pulm edema (phosgene)delayed pulm edema (phosgene)• Bleach + acids/ammoniaBleach + acids/ammoniachlorine chlorine

or chloramine gasor chloramine gas• CS: riot control agentCS: riot control agent

Iron Iron

• See phases (Phase 1: immediate GI sx; See phases (Phase 1: immediate GI sx; phase 2: quiescent; phase 3: acidosis, phase 2: quiescent; phase 3: acidosis, liver injury, GI bleed; phase 4: recovery)liver injury, GI bleed; phase 4: recovery)

• Know different preps have different Know different preps have different amounts (FE amounts (FE fumarate>sulfate>gluconate)fumarate>sulfate>gluconate)

• Deferoxamine (DFO)is antidoteDeferoxamine (DFO)is antidote• Vin rose urine is sign DFO is workingVin rose urine is sign DFO is working

INHINH

• Inhibits pyridoxal Inhibits pyridoxal phosphatephosphateprevents creation of prevents creation of GABAGABA

• Clinical picture is intractable szClinical picture is intractable sz• Causes profound lactic acidosis (“I” Causes profound lactic acidosis (“I”

in MUDPILES or METALACIDGAP)in MUDPILES or METALACIDGAP)• Treatment is pyridoxine (1 g of B6 Treatment is pyridoxine (1 g of B6

for every G of INH ingested, or 5 g for every G of INH ingested, or 5 g empiric dose)empiric dose)

MethemoglobinMethemoglobin

• Change in oxidation of iron in heme Change in oxidation of iron in heme molecule (Femolecule (Fe++++ to Fe to Fe++++++ ) )

• Chocolate brown coloration of bloodChocolate brown coloration of blood• Also the MOA of nitrates in the CN Also the MOA of nitrates in the CN

antidote kitantidote kit• Treatment (if levels >20% or severe sx) Treatment (if levels >20% or severe sx)

is methylene blue 1 mg/kgis methylene blue 1 mg/kg• High-risk persons include those High-risk persons include those

susceptible to oxidative stress (G6PD)susceptible to oxidative stress (G6PD)

Shrooms/PlantsShrooms/Plants

• Shroom you most need to know: amanita Shroom you most need to know: amanita phalloidesphalloides

• Delayed GI sx (>4 h) after ingestion is Delayed GI sx (>4 h) after ingestion is associated with toxic mushrooms (delayed associated with toxic mushrooms (delayed sxsx bad) bad)

• Liver failure is result of A. phalloidesLiver failure is result of A. phalloides• coprinuscoprinus antabuse reaction antabuse reaction• Gyromitra (false or brain morel)Gyromitra (false or brain morel) intractable intractable

sz (INH-like, treated like INH)sz (INH-like, treated like INH)• Amanita muscaria (red shroom)-anticholinergicAmanita muscaria (red shroom)-anticholinergic• Psilocybin (little brown shroom)-hallucinogenPsilocybin (little brown shroom)-hallucinogen


a. phalloidesgyromitra

coprinus

a. muscaria

psilocybin


• PlantsPlants• Cardiac glycosides (yew, oleander, lily Cardiac glycosides (yew, oleander, lily

of the valley, foxglove) dig-like toxicityof the valley, foxglove) dig-like toxicity• Can treat with digibindCan treat with digibind

• Poison Ivy: 3 shiny leaves; blistering Poison Ivy: 3 shiny leaves; blistering rash; type IV allergic reactionrash; type IV allergic reaction

• Jimson weed: anticholinergicJimson weed: anticholinergic• Castor bean: ricin; inhibits RNA, MOSFCastor bean: ricin; inhibits RNA, MOSF


foxglovejimson

ricinPoison ivy

NeurolepticsNeuroleptics

• EPSEPS responds to cogentin/benadryl responds to cogentin/benadryl• Can decrease EPS when giving Can decrease EPS when giving

phenothiazines by pretreating with phenothiazines by pretreating with benadrylbenadryl

• NMS: gradual onset, hyperthermic, AMS, NMS: gradual onset, hyperthermic, AMS, lead pipe rigidity, rhabdo; treat with lead pipe rigidity, rhabdo; treat with benzos, +/- dantrolene, stop agentbenzos, +/- dantrolene, stop agent

• SS: more rapid onset, similar clinical SS: more rapid onset, similar clinical picture except LE more rigid than UE; picture except LE more rigid than UE; consider cyproheptadineconsider cyproheptadine

Nonprescription drugsNonprescription drugs

• Cough & cold prepsCough & cold preps• Dextromethorphan: can x-react with PCP on Dextromethorphan: can x-react with PCP on

U Tox; see nystagmus and AMS/ataxiaU Tox; see nystagmus and AMS/ataxia• Pseudoephedrine: sympathomimetic, Pseudoephedrine: sympathomimetic,

methamphetamine precursormethamphetamine precursor• Vitamins: know Fe contentVitamins: know Fe content• Imidazolines (afrin): look like clonidineImidazolines (afrin): look like clonidine• Oragel: benzocaine, can cause Oragel: benzocaine, can cause

methemoglobinmethemoglobin• Lido patches: seizuresLido patches: seizures

Recreational DrugsRecreational Drugs

• CocaineCocaine• Sodium channel blockadeSodium channel blockade• Sympathomimetic toxidrome, may Sympathomimetic toxidrome, may

see widened QRSsee widened QRS• Metabolite in urine: benzoylecgonineMetabolite in urine: benzoylecgonine• EtOH + cokeEtOH + coke cocaethylene, which cocaethylene, which

may be more toxic than plain cokemay be more toxic than plain coke• Treat with benzos, avoid Treat with benzos, avoid ββ-blockers-blockers

Recreational DrugsRecreational Drugs

• Heroin-already coveredHeroin-already covered• EcstasyEcstasy hyponatremia hyponatremia• GHB: comatose, then wakes up GHB: comatose, then wakes up

suddenly and yanks out ETTsuddenly and yanks out ETT• Ketamine: dissoc anesthetic, Ketamine: dissoc anesthetic,

emergence reactions, intact airway emergence reactions, intact airway reflexesreflexes

• PCP: hallucinations, rotary nystagmusPCP: hallucinations, rotary nystagmus

Sedative-hypnoticsSedative-hypnotics

• BenzosBenzos• Dec LOC, generally need to mix with EtOH Dec LOC, generally need to mix with EtOH

to have sig toxicityto have sig toxicity• Rohypnol: ultra rapid metabolizer, does not Rohypnol: ultra rapid metabolizer, does not

x-react on standard U Toxx-react on standard U Tox• BarbituratesBarbiturates

• Skin bullae, coma, hypothermia; can treat Skin bullae, coma, hypothermia; can treat phenobarb with MDAC/urinary phenobarb with MDAC/urinary alkalinization/HDalkalinization/HD

• SomaSoma• Meprobamate, may cause bezoar/radio-Meprobamate, may cause bezoar/radio-

opagueopague

Strychnine Strychnine

• Increase in excitatory Increase in excitatory neurotransmissionneurotransmission

• Pseudo seizure activity (rigid, Pseudo seizure activity (rigid, opisthotonus, awake)opisthotonus, awake)

• Marked lactic acidosisMarked lactic acidosis• Rat poison is culpritRat poison is culprit

Toxicology in the Core Toxicology in the Core CurriculumCurriculum

Environmental Environmental ToxicologyToxicology

• ArthropodsArthropods• Black WidowBlack Widow

• Presentation is severe abd cramping mimicking acute Presentation is severe abd cramping mimicking acute abd with normal labsabd with normal labs

• Key: may have been working in garage/reaching into Key: may have been working in garage/reaching into pile of lumberpile of lumber

• Treatment: supportive, may try calcium gluconate; Treatment: supportive, may try calcium gluconate; antivenin not generally availableantivenin not generally available

• Brown recluseBrown recluse• Small wound that develops into ulcerSmall wound that develops into ulcer• Treatment: wound care; dapsone has been advocated Treatment: wound care; dapsone has been advocated

before but not used widely d/t risk of MetHbbefore but not used widely d/t risk of MetHb


• ScorpionsScorpions• Centuroides Centuroides only significantly only significantly

venomous species in USvenomous species in US• Neurotoxin that cause Neurotoxin that cause

paresthesias/vomiting/cramping, paresthesias/vomiting/cramping, treatment is supportivetreatment is supportive

• TickTick• Tick paralysis= neurotoxin by Tick paralysis= neurotoxin by

dermocentor sp usuallydermocentor sp usually


• Marine Marine • Scombroid: large fish (tuna, mahi-mahi, Scombroid: large fish (tuna, mahi-mahi,

swordfish), excess histamine in flesh; swordfish), excess histamine in flesh; flush/cramping/diarrhea/hypotensionflush/cramping/diarrhea/hypotension

• Ciguatera: also larger fish, hot/cold Ciguatera: also larger fish, hot/cold reversal in extremitiesreversal in extremities

• Jellyfish: treat with ammonia or urine Jellyfish: treat with ammonia or urine ((not not fresh water) fresh water)

• Lionfish: hot water immersionLionfish: hot water immersion


• SnakesSnakes• Pit viper: diamond shaped head, pits Pit viper: diamond shaped head, pits

anterior to eyes, fangsanterior to eyes, fangs• Crofab: used instead of Wyeth antivenin; Crofab: used instead of Wyeth antivenin;

less risk of anaphylaxis/serum sicknessless risk of anaphylaxis/serum sickness• Pit vipers (rattlers, cottonmouth, Pit vipers (rattlers, cottonmouth,

copperhead) have hemotoxin (low plt, copperhead) have hemotoxin (low plt, coagulopathic) and cause tissue swelling +/- coagulopathic) and cause tissue swelling +/- compartment syndromecompartment syndrome

• Elapids (coral snake, cobras) are neurotoxicElapids (coral snake, cobras) are neurotoxic• Mojave rattler is only NA pit viper with Mojave rattler is only NA pit viper with

primary neurotoxinprimary neurotoxin


• SnakesSnakes

Good Luck!Good Luck!

inservice review: toxicology gerry maloney, do attending physician, emergency medicine and medical...

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