Clinical Toxicology Flashcards
Things activated charcoal are not effective for:
(Micoal) Minerals Iron Cyanide Organic Solvents Alcohol Lithium
Two types cathartics
Saline (Mg) and saccharides (sorbitol)
[True/False] Cathartics can enhance drug removal which decreases morbidity/mortality.
False.
Cathartics have never been shown to decrease morbidity/mortality.
Cathartics contraindications.
Ingestion of corrosives.
What is the best known drug removed by dialysis?
Ethanol
Naloxone
Opioid overdose
Diphenhydramine
Antipsychotics-acute dystonic reactions
Desferroxamine
Iron overdose
Dimercaprol (BAL)
Heavy Metal overdose
N-acetylcysteine
Tylenol overdose
Glucagon
For insulin and beta blocker overdose
Methylene blue
Nitrate overdose
Pralidoxime (2-PAM)
Organophosphate overdoses
CaNa2EDTA
Heavy Metal overdose
Sodium Thiosulfate
Cyanide overdose
Ethanol
Antifree (its metabolite-ethylene glycol) and methanol overdose
Pyridoxine (Vitamin B6)
INH overdose
Can be used in Ethylene Glycol Overdose
Phentolamine (alpha-1 antagonist)
Any alpha-1 agonist overdose
Pseudophedrine
Syrup of Ipecac Contraindications
Gastric Lavage Contraindication
Unprotected airway
Hydrocarbons
Corrosives
Cocaine Toxidromes
Sympathomimetic Euphoria CVAs are common Rhabdomyalysis (muscle break down) Hyperthermia Possible seizures
Management of Cocaine Overdose
Anxiety/psychosis
Diazepam/haloperidol
Management of Cocaine Overdose
Sinus tachycardia
Observation/diazepam
Management of Cocaine Overdose
Hypertension
Labetalol
Management of Cocaine Overdose
Headache (HA)
CT scan (could be due to bleeding)
Management of Cocaine Overdose
Seizures
Phenytoin/diazepam/CT Scan
Management of Cocaine Overdose
MI
Nitrates, Calcium Channel blockers, avoid Beta-blockers
Management of Cocaine Overdose
Rhabdomyalysis
Alkalinization of urine (bicarbonate)
Management of Cocaine Overdose
CVA
Supportive
Carbon Monoxide Poisoning Treatment
Supplemental 100% oxygen
Carbon Monoxide Poisoning Treatment
Supplemental 100% oxygen
Two types cathartics
Saline (Mg) and saccharides (sorbitol)
[True/False] Cathartics can enhance drug removal which decreases morbidity/mortality.
False.
Cathartics have never been shown to decrease morbidity/mortality.
Cathartics contraindications.
Ingestion of corrosives.
What is the best known drug removed by dialysis?
Ethanol
Naloxone
Opioid overdose
[True/False] You can induce emesis when someone overdoses on TCAs or do gastric lavage.
False
Do not induce emesis in someone with a TCA overdose
Only do lavage if less than 1 hour post ingestion
TCA Overdose QRS interval meaning:
0.10-0.15
0.16
Below 0.10
Correlates with increased risk of seizures
Correlates with increased risk for both seizures and arrhythmia
Dose not rule out the possibility of toxicity
Dimercaprol (BAL)
Heavy Metal overdose
N-acetylcysteine
Tylenol overdose
Classical triad of opioid intoxication
Miosis (pupil constriction)
Respiratory Depression
Depressed level of consciousness
Methylene blue
Nitrate overdose
Pralidoxime (2-PAM)
Organophosphate overdoses
CaNa2EDTA
Heavy Metal overdose
Sodium Thiosulfate
Cyanide overdose
Ethanol
Antifree (its metabolite) and methanol overdose
Pyridoxine (Vitamin B6)
INH overdose
Phentolamine (alpha-1 antagonist)
Any alpha-1 agonist overdose
Pseudophedrine
Syrup of Ipecac Contraindications
Less than 6 months
Seizing or comatose patients
Corrosive substances
Gastric Lavage Contraindication
Unprotected airway
Hydrocarbons
Corrosives
Cocaine Toxidromes
Sympathomimetic Euphoria CVAs are common Rhabdomyalysis (muscle break down) Hyperthermia Possible seizures
Management of Cocaine Overdose
Anxiety/psychosis
Diazepam/haloperidol
Management of Cocaine Overdose
Sinus tachycardia
Observation/diazepam
Management of Cocaine Overdose
Hypertension
Labetalol
Management of Cocaine Overdose
Headache (HA)
CT scan (could be due to bleeding)
Management of Cocaine Overdose
Seizures
Phenytoin/diazepam/CT Scan
Management of Cocaine Overdose
MI
Nitrates, Calcium Channel blockers, avoid Beta-blockers
Management of Cocaine Overdose
Rhabdomyalysis
Alkalinization of urine (bicarbonate)
Treatment of Organophosphate Poisoning
Flushing of body
Atropine for CNS and nicotininc effects
2-PAM for CNS effects
When there is inadequate tissue oxygenation is metabolic alkalosis or acidosis present?
Metabolic acidosis
Carbon Monoxide Poisoning Treatment
Supplemental 100% oxygen
What two medications are chemically and structurally similar to TCAs?
Carbamazepine
Cyclobenzaprine
TCA Cardiac Toxicity Signs
Tachycardia and HTN
Vasodilation
Myocardial depression and cardiac conduction from inhibition of fast Na+ channels
TCA CNS Toxicity
Sedation/coma from anticholinergic effects
Seizures from NE and Serotonin reuptake inhibition
Clinical Presentation of TCA toxicity
TCA
Tonic-clonic seizures
Cardiac
Anticholinergic
TCA Bicarbonate Mechanisms
Increases plasma protein binding
Stabilization of fast Na+ channels
What is your optimum pH of the blood when treating TCA overdose?
7.45-7.55
[True/False] You can induce emesis when someone overdoses on TCAs or do gastric lavage.
False
Do not induce emesis in someone with a TCA overdose
Only do lavage if
TCA Overdose QRS interval meaning:
- 10-0.15
- 16
Correlates with increased risk of seizures
Correlates with increased risk for both seizures and arrhythmia
Dose not rule out the possibility of toxicity
TCA Contraindications
Physostigmine
Flumazenil
What vasopressors can be used in a TCA overdose if needed?
NE and phenylephrine
Dopamine should be avoided secondary to depletion of amines.
Classical triad of opioid intoxication
Miosis (pupil constriction)
Respiratory Depression
Depressed level of consciousness
Signs of Beta-Blocker Overdose
Bradycardia and depression of inotropy (force of contraction)
Treatment of Beta-Blocker Overdose
Glucagon 3mg IV
Can follow-up with continuous infusion.
Monitor for hyperglycemia
Where does hydrocarbon toxicity mainly come from?
Aspiration
Pneumonitis
Group 1 Hydrocarbons
Greases (non-toxic)
Group 2 Hydrocarbons
Kerosene, gasoline
Group 3 Hydrocarbons
Ring hydrocarbons-benzene
Group 4 Hydrocarbons
Chlorinated hydrocarbons: carbon tetrachloride
Hallmarks of Phencyclidine (PCP) toxicity
Violent or bizarre behavior
What is the primary concern of PCP toxicity?
Self-induced injury.
What can achieve chemical calming in PCP toxicity?
Haloperidol or diazepam
What are the characteristics of Theophylline toxicity?
N/V, agitation
Dysrhythmias and seizures
What levels of Theophylline does toxicity begin?
20mg/L
What are life threatening levels of Theophylline toxicity?
50-60mg/L
What exacerbates Theophylline toxicity?
Hypokalemia
What do seizures due to Theophylline toxicity respond to?
Phenytoin
Diazepam
In severe seizures due to Theophylline toxicity what do you want to consider to treat it?
Hemoperfusion
What three deleterious effects do organophosphates have on the body systems?
Parasympathetic-SLUDGE
Nicotinic-muscle weakness
CNS-confusion, slurred speech, respiratory depression
Treatment of Organophosphate Poisoning
Flushing of body
Atropine for CNS and nicotininc effects
2-PAM for CNS effects
Characteristics of Barbiturate poisoning
Respiratory depression
Hypotension
Decreased level of consciousness
Clinical Presentation of Barbiturate poisoning
Slurred speech Lethargy Ataxia Hypothermia Coma Death
Treatment of Barbiturate poisoning
Forced diuresis
Alkalinization of the urin
Multiple dose charcoal
Normal Plasma Blood levels of Barbiturates
15-40mg/L
Clinical Presentation of BZDs
Lethargy Slurred speech Ataxia Respiratory Depression Coma
Avoid ____ especially in ultra-short acting BZDs due to rapid progression to coma.
Emesis
What is indicated for pure benzo overdoses only?
Flumazenil
What is the dose of flumazenil for benzo overdose?
0.2mg IV repeat with 0.5mg every 1 min. until response is achieved or to a max dose of 3mg
How does methanol become toxic?
It is metabolized and its metabolites are toxic.
formic acid
How does methanol toxicity present itself?
Osmolar/anion gap.
What do you always draw in methanol toxicity?
ASA/APAP and ethylene glycol levels
Treatment of Methanol Toxicity
EtOH therapy: 10% EtOH in D5W over 30-60 minutes then start 1.39ml/kg/h of 10% EtOH solution.
EtOH bind alcohol dehydrogenase, preventing methanol metabolism
Folinic Acid and folic acid-enhances the conversion of formate to CO2 and H2O.
4-methylpyrazole/Fomepizole (4-MP)-blocks alcohol dehydrogenase without causing inebriation.
Hemodialysis-removes methanol and formate from the circulation
How is ethylene glycol toxic?
Glycolic acid accumulates and causes renal tubular damage. Glycolic acid is metabolized and the metabolites can cause acidosis and some can form oxalate crystals in tissues (within 1-3 hours).
Ethylene Glycol Toxicity
Stage 1
CNS Stage:
30 minutes to 12 hours
Characterized by intoxication, slurred speech, lethargy, ataxia.
Patients may complain of GI distress
Ethylene Glycol Toxicity
Stage 2
Cardiac Stage:
Occurs 12-48 hours after ingestion and is characterized by cardiac edema, cardiac dilation, and the development of arrhythmias.
Death is most common during this stage.
Ethylene Glycol Toxicity
Stage 3
Renal Stage:
Occurs 24-72 hours after ingestion
Characterized by development of acute renal failure, flank pain, and CVA tenderness on physical exam.
In Ethylene Glycol overdose what levels must you draw and what must you monitor?
Draw ASA/APAP levels
Place patients on an EKG monitor.
Treatment of Ethylene Glycol Toxicity
Gastric Lavage if less than 4 hours post ingestion
Bicarbonate for metabolic acidosis
Calcium Chloride or Calcium Gluconate for hypocalemia
Ethanol
4-MP
Thiamine, pyridoxin, and folate
Hemodialysis in cases with ARF or high serum EG levels (more than 50mg/L)
Childhood ingestions are usually single _____, _____, and _____ recognized.
Single chemical agents
Known
Promptly recognized
Adult/adolescent ingestions are usually multiple chemical agents, intentional, ____, and with _____ recognition.
Unknown
Delayed
What is the most common cause of toxic ingestions in the elderly?
Chronic overmedication (polypharmacy)
What do you want to identify in a patient that you believed has overdosed?
Substance
Amount
Route
What do you look for upon physical exam?
Vital signs Coma grade/level of consciousness Neurologic findings (seizures, nystagmus, miosis (cholinergics), mydriasis (anticholinergics), fixed dilated pupils) Cardiac-(dysrhythmias) Odors
What are some lab assessments that you can obtain during an overdose?
Electrolytes (anion gap) Blood gases Serum osmolality EKG Toxic Screen
Treatment Principals are?
Provide supportive care Prevent absorption Enhance elimination Interrupt or alter metabolism Provide specific antibiotics