Toxicology Flashcards
What are the top 3 medications that can be given to a patient in a coma that wont hurt them and might fix it?
What is the triad of opioid overdose?
Whats first line medication for seizure?
Glucose
Naloxone (Narcan)
Thiamine
Triad of opioid overdose:
- CNS depression
- Resp depression
- Miosis (constriction)
Seizure med: diazepam, if this fails give phenobarbital
Decontamination:
- when is emesis indicated?
- which medication can be used to induce vomiting?
- when is emesis CI?
Emesis indicated:
- only in patiens with intact gag reflex
- must be within 1hr of ingestion
- for drugs not absorbed by charcoal
Medication used to induce vomiting = ipecac
CI:
- if caustic or low viscosity hydrocarbons have been ingested
- rapid acting convulsants have been ingested (amphetamines, cocaine, cyclic antidepressants, strychnine)
Decontamination:
-gastric lavage indications
- activated charcoal
- -MOA
- -dosage
- -why do we mix with sorbitol?
- what toxins does it not work on?
- bowel irrigation
- -indications
- -medication used
Gastric lavage indications:
- suspected serious ingestions when emesis has failed
- pts are lethargic or uncooperative
- gag-reflex is markedly depressed
ACTIVATED CHARCOAL:
-MOA: binds most poisons, great absorption
- Dosage: if ingested poison is known, give at least 10x that weight in activated charcoal.
- Mix with sorbital to improve tasste and provide cathartic action (speeds up GI transit, but gives you lots of pain)
- PAIL
- -potassium
- -alcohol
- -iron
- -lithium
Bowel Irrigation:
- indications: useful with sustained release and enteric coated labs.
- med: golytely
Toxicology:
-initial studies
lab studies:
- ABGs
- Chem 7 (BMP)
- EKG
- CXR
- Flat plate Xray
- urine tox
- tox screens for indicated substances.
Toxicology Kinetics:
- what is first order kinetics?
- what is zero order kinetics?
- Toxins with large volumes of distribution are effeciently/not effectiently removed by dialysis or diuresis?
-hemodialysis is effective at eliminating toxins with what property? examples.
Hemoperfusion is effective at elminating toxins with what properties? examples/
First order = a fixed % of the toxin is removed per unit time
Zero order = a fixed amount of toxin is removed per unit time
ARE NOT EFFICIENTLY
Hemodialysis is effective at eliminating toxins that are water-soluble and not highly protein bound. Ex: MELS -methanol -ethylene glycol -lithium -salicylate
Hemoperfusion is effective at eliminating toxins with poor water solubility, lipid soluble, and highly protein bound. Ex. TRI PEP-TD -TCA -paraquat -ethchlorvynol -phenobarbital -theophylline -digitoxin
What is the antidote for:
- acetaminophen
- anticholinergics
- benzos
- cyanide
- methanol/polyeth/ glycol
- narcotics
Acetaminophen: acetylcysteine
Anticholinergics: physostigmine
Benzos: Flumazenil
Cyanide: Na nitrite and Na thiosulfate
Methanol/polyeth. glycol : ethanol
Narcotics: naloxone
What is the MC cause of a change in osmolar gap greater than 30?
Acetaminophen:
- max dose?
- toxic dose?
- how long does it take for hepatotoxicity to develop?
- when is the best time to draw an acetaminophen level?
- tx of toxicity
ethanol
Acetaminophen:
- max dose: 3g
- toxic dose: 6g or greater than 140mg/kg
delayed hepatotoxicity 24-72hrs post ingestion
Best to draw acetaminophel level within 4 hrs post-ingestion
Toxicity:
- give activated charcoal
- acetylcysteine (must be given EARLY!! within 8-16hrs)
Acetaminophen Toxicity:
- sx at each of the following time intervals:
- -4hrs
- -24-48hrs
- -3-5days
- -one week out
4hrs: anorexia, n/v, sweating, may be asymptomatic
24-48hrs: abnornormalities in LFT, abd pain
3-5d: jaundice, hypoglycemia, coagulopathies, encephalopathies, renal failure
One weeK: if they make it this far they start to come back to normal.
Cocaine/Amphetamines:
- overdose sx and signs
- tx of overdose
signs and sx:
-htn
- bradycardia
- ventricular arrhythmias
- seizures & hyperthermia may cause rhabdo and myoglobinuria
- euphoria
- excitement
- restlessness
- toxic psychosis
- MI
Tx:
- GI decontamination
- tx seizure with diazepam
- DBP greater than 120 or HTN encephalopathy = nitroprusside
- EKC
- CT of head
Anticholinergics:
- examples
- sx
- tx
Examples:
-scopolomine, belladona, antihistamines, tcas, nightshade (makes you sleepy), atropine
Sx: -delerium -blurred vision -mydriasis (dilation) -hallucinations -coma -dry mucous membranes -inhibition of sweating -hyperthermia -tachycardia "Hot as a hare, red as a beet, dry as a bone, blind as a bat, and mad as a hatter" (crazy)
Tx:
- supportive
- GI decontamination
- physostigmine IV only if SEVERE!
Anticoagulants: WARFARIN:
- works on which clotting factors?
- tx
Clotting factors: II, VII, IX, X
Tx:
- supportive/GI decontamination
- baseline PT/INR
- VIt K
- FFP in a bleeding emergency
Arsenic:
- sources
- types of toxicity
- -sx of each type
- -tx
Sources:
- shellfish*
- insecticides
- in the soil
Types:
-Acute, Chronic, and Gas toxicity
Sx:
- Acute ingestion:
- -crampy abd pain, vomiting, profuse watery diarrhea, burning mucosa, conjuncitivits, tremor, seizures
- -garlic order may be present on breath
- -periorbital edema after 1-2days
- Chronic ingestion:
- -peripheral and sensory neuropathy, malaise, anorexia, alopecia, anemia, stomatitis
- Arsine Gas:
- -intravascular hemolysis and renal failure
Tx:
-acute: GI decontamination w/ GI lavage and charcoal
- chronic: penicillamine
- arsine gas: blood transfusion may be necessary, adequate hydration to prevent renal hgb.
Carbon Monoxide:
- sx
- can we trust a pulse oximiter for an accurate hgb sat reading?
- tx
Sx:
- wake up with a HA and it gets better at work
- minimal sx, no loss of consciousness
- fatigue
- malaise
- nausea, confsion, dizziness
- paresthesias
- lethargy
- chest pain, MI, hypotension, cardiac arre
NO! pulse oximetry cannot be used to access oxygenation b/c the device confuses COHgb for O2Hgb and gives falsely high values.
Tx:
-100% FiO2 for 4 hours (half life of COhgb is 4h on RA and 60mins when breaing 100% FiO2 and 15mins with 100% FiO2 at 2.5 atm w/ HBO)
HBO indicated if AMS, abnormal neuro exam, coma, myocardial ischemia, pregnant, thermal/chemical burns.
Digitalis:
- MOA on CV?
- sx
- EKG findings
- what electrolyte abnormalities is associated with digatalis overdose?
MOA:
- enhance cardiac contractility
- slow AV conduction
- enhances automaticity
Sx:
- anorexia
- nausea
- vomiting
- diarrhea
- abd pain
- blurred vision
- color vision disturbance
EKG findings: 3rd degree AV block, bradycaria, ventricular ectopy, or paroxysmal atrial tachycardia with AV block
Hyperkalemia is associated with acute in gestion of an overdose of digitalis.
Digitalis:
-tx
Tx:
-if hyperkalemia (greater than 7) treat with glucose + insulin thereapy
- symptomatic bradycardia, 2nd/3rd degree AV block = atropine and maybe pacing
- Ventricular ectopy use lidocaine
- Fab fragments (Digibind)**
Consequences of administering digibind to a patient with digitalis toxicity?
Following administration of digibind the serum digoxin level may increase by as much as 20x. most labs measure total serum digitalis with assay. bound digitalis is not active drug but is still in the serum and may alter your test result.
Ethanol:
- sx
- treatment
Sx:
- ataxia
- dysarthria
- depressed sensorium
- nystagmus
Tx:
- supportive
- thiamine
- watch blood glucose
Mushrooms:
-what are the top 5 medically significant mushrooms?
ShroomS:
-amanita phalloides** (hepatic and renal failure, tx is supportive)
- inocybe or clitocybe
- psilocybe
- a. muscaria
- gyromitra
Opiates:
- sx
- opiate overdose should be considered in any pt who is unconscious from unknown cause, T/f?
- tx
- which med overdose can mimic this but is not treated with the opiate antidote?
Sx:
- sedation
- hypotension
- bradycardia
- hypothermia
- resp depression.
*Triad = decreased RR, CNS depression, miosis (constriction)
True.
Tx:
- Naloxone IV
- naloxones half life is 1hr and effects last only 2-3hrs, most opiates require repeated doses.
Clonidine overdose may appear identical to opiate overdoses but they do not respond to naloxone
Organophosphates:
- sources
- MOA
- sx
- tx
Sources: insecticides
MOA:
-inhibits Ach esterase, leaving us with a lot of Ach in the junction.
Sx:
- DUMBELS
- -diarrhea, urination, miosis bronchospams, excitation, lacrimation, salivation
-tachycardia or bradycardia
Tx:
-decontamination and aggressive airway management d/t significant secretions and bronchospasms
-IV Atropine in LARGE doses
-Pralidoxime (inhibits binding of organophosphates to Ach)
-
Phencyclidine (PCP):
- effects
- sx
- tx
Effects: hallucinogenic, sympathomimetic, dissociate agent
Sx:
-paranoid, bizzare, violent behavior, quiet stupor, multi-directional nystagmus**
-hTN, tachycardia, hyperthermia, muscle rigidity, dystonias, seizures
Tx:
- limit seizures and violence with diazepam or haloperidol
- monitor and prevent rhabdo
TCA:
-sx
-
Sx: anticholinergic sxx
- mydriasis (dilation)
- dry mouth
- tachycardia
- agitation
- hallucinations
- onset of coma may be rapid
- seizures
- QT prolongation** = death. :(
- widening of QRS
- AV block and Vtach are common
- torsades de point
- profound HYPOTENSION***** (d/t decreased contractility and vasodilation occurs and often cause of death
- **3 Cs:
- cardiac abnormalities, convulsions, coma
Tx:
- GI decontamination
- Gastric lavage and instill charcoal
- tx seizure with diazepam
- treat ventricular arrhythmias with NaHCO3, Lidocaine, phenytoin
- hypotension treated with NaHCO3 and crystalloid
