Toxicology Flashcards
This deck covers Chapters 139-159 in Rosens, compromising all of toxicology.
Outline treatment for BB/CCB poisoning
- MOVID
- ABCs
- Charcoal/WBI
- Fluids, Pressors
- Calcium
- Glucagon 5 mg IV
- Insulin R 1-10 units/kg/hr
- Intralipid
- ECMO
Identify the following:
Water Hemlock
Signs/Symptoms
- N/V
- Seizures (GABA antagonism)
Treatment
- Charcoal
- Seizure control
Outline the metabolism of ethylene glycol
Ethylene glycol
- Alcohol dehydrogenase
- NAD as cofactor
Glycoaldehyde
- Aldehyde dehydrogenase
- NAD as cofactor
Glycolic acid
- NAD as cofactor
Glycoxylic acid
- Pyridoxine as cofactor (glycine)
- Thiamine and Mg as cofactor (a-hydroxy-…)
Oxalic acid + Glycine + a-hydroxy-b-ketoadipate
List 6 radio-opaque drugs
CHIPES
- CaCO3
- Heavy metals
- Iron
- Potassium
- Enteric-coated pills
- Solvents
List 5 benefits of fomepizole over alcohol
- Ease of administration
- Standardized
- Predictable
- Safer
- Longer duration of action
- No CNS effect
- ADH has higher affinity to fomepizole than alcohol
In asymptomatic or minimally symptomatic children, what guides lead chelation therapy?
Leads sucks (69)
- BLL >69 - hospitalize
- BLL 45-69 - OP oral succimer
- BLL <45 - no chelation
List 5 non-selective and 4 selective beta-blockers
Non-Selective
- PLaNTS
- Propranolol
- Labetalol
- Nadolol
- Timolol
- Sotalol
Selective
- BEAM
- Bisoprolol
- Esmolol
- Atenolol
- Metoprolol
Differentiate the type of injury caused by acids/alkalis
Acids
- Coagulative necrosis
- Concern re: systemic absorption
Alkalis
- Liqufactive necrosis
- Deeper penetration
What is the mechanism of action of CN and H2S?
Binds Complex IV in the electron transport chain
Uncouples oxidative phosphorylation
Outline management of ASA poisoning
- IV fluids
- U/O at 2-3 cc/kg
- Alkalinize the urine
- NaHCO3 infusion
- Target urine pH >7.5
- Replace potassium
- KCl in fluids
- Maintain glucose
- Target >5.5 mmol/L
- Consider dialysis
- Coma, Seizure
- Renal failure
- Hepatic failure
- Respiratory failure
- Severe acidosis
- Rising ASA level
- Acute level >7.2
- Chronic level >3.6
List 6 drugs that intralipid is indicated for.
- BB
- CCB
- Local anesthetic
- Buproprion
- TCAs
- Seroquel
- Diphendydramine
- Class I antiarrhythmics
List the antidote and dose for the following drugs/poisons:
- Iron
- Isoniazid
- Lead
- Local anesthetics
- MDMA-related hyperpyrexia
- Neuroleptics (NMS)
- Methanol
- Methemoglobin
- Opioids
- Iron - Deferoxamine 15 mg/kg/hr IV
- Isoniazid - Pyridoxine 5g IV
- Lead - DMSA 10 mg/kg PO
- Local anesthetics - Intralipid 1.5 mL/kg IV
- MDMA-related hyperpyrexia - Dantrolene 2.5 mg/kg IV
- Neuroleptics (NMS) - Dantrolene 2.5 mg/kg IV
- Methanol - Fomepizole 15 mg/kg, Folate 50 mg IV
- Methemoglobin - Methylene blue 1-2 mg/kg
- Opioids - Narcan 0.4 mg IV
Pulmonary irritants react with water to cause damage. Give 4 examples.
- Chlorine –> HCl
- Phosgene –> HCl
- Ammonia –> Ammonium hydroxide
- Sulfur dioxide –> H2SO4
When do you initiate lab testing (AST + APAP) in chronic APAP ingestion (3)?
- Ingestion >10g/day x24h
- Ingestion >6d/day x48h
- Symptomatic (N/V, RUQ pain, Jaundice)
List 7 drugs which enhance lithium toxicity
Renal Toxins
- NSAIDs
- Diuretics
- ACEi
- ARB
Neuro/Psych Meds
- SSRI
- Antipsychotics
- Carbamazepine
List 5 drugs that induce CYP P450
- Sulfonylureas
- Phenobarbital
- Rifampin
- INH
- Phenytoin
- Carbamazepine
- HIV medications
- St. John’s wart
- Chronic EtOH
List 7 causes of a toxin-induced bradycardia
- CCB
- BB
- Opiate
- Clonidine
- Digoxin
- Barbiturates
- Organophosphates
List 5 reasons why the Done nomogram is not useful in all patients
- Derived in pediatric population
- Assumes 1st order kinetics
- pH must be >7.4
- Toxicity correlates poorly with serum levels
- Used after 6h from single, non-EC ASA dose
How do you approach the following patients with iron ingestion?
- Asymptomatic, Ingestion <20 mg/kg, Level <60
- Asymptomatic, Ingestion >20 mg/kg, Pills on Xray
- Symptoms and level 60-90 umol/L
- Ingestion >60 mg/kg, level >90 umol/L
Asymptomatic, Ingestion <20 mg/kg, Level <60
- Observe x6h, then psych vs home
Asymptomatic, Ingestion >20 mg/kg, Pills on Xray
- Get level at 4h and 8h
- WBI
- If level >60 or systemic symptoms = chelate
- If level <60 and decreasing = don’t chelate
Symptoms and level 60-90 umol/L
- Chelate (DFO 15 mg/kg/hr)
Ingestion >60 mg/kg, level >90 umol/L
- Chelate (DFO 15 mg/kg/hr)
List 8 indications for DigiFab
Adult
- Cardiac arrest
- Ventricular dysrhythmia
- Symptomatic, refractory bradycardia
- Progressive rhythm disturbance
- Potassium >5
- Increasing potassium
- Co-ingestion with CCB, BB, TCA
- Ingestion of plant containing drug AND dysrhythmia
- >10 mg ingestion with any of above
- Digoxin level >6 with any of above
Children
- Same as adults except K >6 and level >5
What kinetics does ASA undergo in therapeutic vs toxic ranges?
Therapeutic = 1st order
Toxic = zero order
List 10 indications for HD in ASA toxicity
- Coma
- Seizure
- Renal failure
- Hepatic failure
- Respiratory failure
- Severe acidosis
- Rising ASA level
- Acute level >7.2
- Chronic level >3.6
- Pregnant
- Intubated
List the antidote and dose for the following drugs/poisons:
- Organophosphates/Carbamates
- Rattlesnake bite
- Serotonin syndrome
- Sulfonylureas
- TCAs
- Valproate
- Organophosphates - Atropine 1 mg then double
- Rattlesnake bite - CroFab 5 vials
- Serotonin syndrome - Cyproheptadine 4 mg PO
- Sulfonylureas - Octreotide 50 ug SC
- TCAs - Bicarb 1 mEq/kg, Intralipid 1.5 mL/kg
- Valproate - Carnitine 100 mg/kg IV
Outline the degree of IRON toxicity in terms of the amount ingested and serum iron level
No Toxicity
- Ingested <20 mg/kg
- Serum <30 umol/L
Mild
- Ingested 20-40 mg/kg
- Serum 30-60 umol/L
Moderate
- Ingested 40-60 mg/kg
- Serum 60-90 umol/L
Severe
- Ingested >60 mg/kg
- Serum >90 umol/L
Name 4 different chelators
- Deferoxamine
- BAL
- DMSA
- EDTA
- D-Penicillamine
List 3 reasons to start NAC in chronic ingestions
- AST >2x normal
- AST elevated + APAP >66 umol/L or symptomatic
- APAP greater than expected/toxic
List contraindications to activated charcoal
- Can’t absorb toxin
- Caustic ingestion
- Aspiration
- Ileus
- Perforation
- Airway not protected
What 5 hydrocarbons have increased toxicity?
CHAMP
- Camphor
- Halogenated Hydrocarbons
- Aromatic hydrocarbons
- Metals
- Pesticides
List 6 ingested overdoses in which you would consider WBI
Basically, anything that is very toxic
- Heavy metals
- BB
- CCB
- TCA
- Iron
- Lithium
- Extended-release formulations
- Bezoar forming drugs
Differentiate acute and chronic lithium overdose by:
- Cause
- Presenting symptoms
- Usefulness of WBI
- Levels for HD
Cause
- Acute - overdose
- Chronic - AKI, dehydration, drug interaction
Presenting symptoms
- Acute - GI, Cardiac
- Chronic - Neuro
Usefulness of WBI
- Acute - helpful
- Chronic - not helpful
Levels for HD
- Acute - >4 mEq/L
- Chronic - >2.5 mEq/L
What is the dose of deferoxamine? Indications (3)? Adverse effects (4)?
Dose
- 15 mg/kg/hr x24h
Indications
- Systemic toxicity
- Level >90 umol/L
- Ingestion >60 mg/kg
Adverse Effects
- Hypotension
- Anaphylactoid reactions
- Pink urine
- Ototoxic
- ARDS
- Yersinia sepsis
Name 5 drugs that could be used to treat a hypertensive emergency secondary to cocaine
- Benzodiazepines
- Phentolamine
- Nitroglycerin
- Nitroprusside
- Hydralazine
- Diltiazem
AVOID BETA-BLOCKERS –> Unopposed alpha
List 6 causes of a ‘double gap’ (Anion + Osmolar)
- DKA
- AKA
- Ethylene glycol
- Methanol
- Propylene glycol
- Lactate
- MODS
- Chronic renal failure
List three types/forms of mercury
- Elemental
* Not absorbed
* Inhaled - Inorganic salt
* GI/GU toxin - Organic
* GI/Skin toxic
* Neuro symptoms
How are inhaled toxins classified (4)?
- Asphyxiant (simple)
* Takes up space, so no oxygen
* CO2, N2, Helium - Asphyxiant (chemical)
* Inhibits oxygen utilization
* CN, CO - Irritant (high solubility)
* Danger quickly (laryngospasm, bronchospasm, eyes)
* Ammonia, HF, HCl - Irritant (low solubility)
* Danger later (pneumonitis, ARDS)
* Phosgene
What drugs require urinary alkalinization?
STAMP CAME
- Sulfonamides
- TCAs
- ASA
- MTX
- Phenobarbital
- Cocaine
- Antihistamines
- Methanol
- EG
What is the mechanism of action of physostigmine? Adverse reactions? Contraindications?
MOA = AChEi
A/E = Cholinergic excess (Seizures)
CI = QRS >100 ms, TCAs
What are the 5 Hunter Criteria for serotonin syndrome?
Known exposure to serotonergic drug:
- Spontaneous clonus
- Inducible clonus AND Agitation or diaphoresis
- Ocular clonus AND Agitation or diaphoresis
- Tremor AND Hyperreflexia
- Tone AND Temperature AND Clonus
Name 8 drugs with primarily anticholinergic toxicity
- Atropine
- Scopolamine
- Homatropine
- Cyclopentolate
- Glycopyrrolate
- Atrovent
- Benztropine
- Diphenhydramine
A patient thought to be inhaling hydrocarbons arrives in VT. How do you alter ACLS?
- Add esmolol or lidocaine
- Avoid epinephrine
Outline your management of stimulant-induced hyperthermia
- Identification
- MOVID
- ABCs
- Benzos
- Ketamine if necessary
- Ice packs
- Cold IV fluids
- Intubate/Paralyze if necessary
- Antibiotics
- B/W including BCx, CK/urine myoglobin
What are the 3 treatment goals for EG/Methanol toxicity
- Correct acidosis
- Bicarb to pH 7.45-7.5
* Aggressive in Methanol (save sight)
* Careful in EG (worsen hypoCa) - Enhance clearance
- HD
- Prevent metabolism
- Alcohol/Fomepizole
- Thiamine 100 mg/Pyridoxine 50 mg + Folate 50 mg
Name the 3 binding sites on a GABA receptor.
- GABA
- BZD
- EtOH/Barbituates/GHB
List 4 indications for HD in lithium poisoning
- Acute >4, Chronic >2.5
- CNS symptoms (seizure, decreased LOC)
- Renal insufficiency
- Can’t tolerate volume