Toxicology 2 Flashcards
When is gastric lavage effective? (timing)
If w/in 60 min of ingestion
(reserved for life threatening substances)
How does activated charcoal work? When should you avoid this?
- Directly absorbs substance and interrupts enterohepatic recirculation
- Avoid in perforation, obstruction, vomiting, or if endoscopy planned
What 8 things are NOT absorbed by charcoal? (“CHARCOAL”)
- Caustics, Corrosives
- Heavy metals, Hydrocarbons
- Alcohols, Alkali/Acids
- Rapidly absorbed substances
- Cyanide
- Other insoluble drugs
- Allopathic substances
- Lithium, Laxatives
What 5 things is GI decontamination (whole bowel irrigation- Golytely) good for?
(“Pack LIES”)
- Iron
- Lithium
- Sustained release substances
- Enteric coated pills
- “Packers”
*use is now controversial*
When is IV lipid emulsion indicated? (2 situations)
For overdoses of lipophilic agents w/:
1. Cardiac arrest (stop 10 min after get pulse back)
or
- Significant hemodynamimc instabbility failing conventional therapy
IV lipid emulsion is useful for what 7 agents?
- Cocaine
- Propranolol
- Bupropion
- Amitriptyline
- Diltiazem, Verapamil
- Lamotrigine
What is the toxidrome for anticholinergics?
(Will be on exam)
- Hot as Hell
- Blind as a Bat
- Dry as a Bone
- Red as a Beet
- Mad as a Hatter- agitated
- Fixed dilated pupils
- hyperthermic
- DRY ARMPITS
The following are possible causes of which toxidrome?
- Jimson weed
- Antihistamines (Diphenhydramine)
- Antidepressants
- Scopolamine
- Cyclobenzaprine
- Carbamazepine
Anticholinergic toxidrome
How do you treat a patient with anticholinergic toxidrome?
- ABCs
- Supportive care
- Rapid cooling
- Benzos for agitation
What is the cholinergic (Muscarinic) toxidrome?
(“every system is leaking”)
“SLUDGE”
- Salivation
- Lacrimation
- Urination
- Diarrhea
- GI cramps
- Emesis
Also have sweating and Miosis
What is the cholinergic (Nicotinic) toxidrome?
(“Monday-Sunday”)
- Monday – Miosis
- Tuesday – Tachycardia
- Wednesday – Weakness
- Thursday – Tremors
- Friday – Fasciculations
- Saturday – Seizures
- Sunday – Somnolent
What are the clinical features of the sympthomimetic toxidrome? How is it different from the anticholinergic toxidrome?
(sympathomimetic= Amphetamines, cocaine, pseudophedrine, caffeine, PCP)
- ↑BP and HR
- Delusions
- _*Hyperthermia_
- Seizure
- _*Diaphoresis_
- Piloerection
- _*Mydriasis_
- Hyperreflexia
When does serotonin syndrome occur?
Usually occurs in patients taking 2 SSRIs
(ex: Lithium + MAOI)
A person with _____ syndrome might have the following clinical effects:
- Confusion - agitation - seizure - coma
- Fever, tachycardia, diarrhea, mydriasis
- Ataxia, hyperreflexia, clonus
Serotonin syndrome
How do you treat serotonin syndrome?
Treatment is supportive:
- Remove offending agent
- Reduce temperature
- Judicious use of benzodiazepines
The following are symptoms of which toxidrome?
- Pin point pupils
- depressed respirations
Opiate toxidrome
THe following is tx for which toxidrome
- ABCs
- Naloxone
Opiate toxidrome
Summary of comparison of the following toxidromes: Anticholinergic, cholinergic, opioid, sympathomimetic and sedative-hypnotic
KNOW THIS!
Which Toxidrome?
22 y/o M presents w/ agitation, HTN, tachycardia, mydriasis and diaphoresis
Sympathomimetic
Which toxidrome? What other toxidrome might this be confused with and why?
17 y/o presents with tachycardia, hyperthermia, mydriasis, dry skin and hallucinations?
Anticholinergic
This might be confused with sympathomimetic- the only difference is the skin. In sympathomimetic, the patient would be diaphoretic
Which toxidrome?
40 year old with altered mental status, bradypnea, hypoxia
Opioid
Which toxidrome?
22 year old with vomiting, diarrhea, and urinary incontinence
Cholinergic
(leaking from every system)
What is the MC potentially toxic pharmaceutical drug overdose?
Acetaminophen toxicity
Acetaminophen toxicity:
Acute alcohol ingestion blocks_______ system and thus ↓s toxicity –-> chronic use ↑s risks because of glutathione depletion
P450
Acetaminophen toxicity:
Should check 4 hour level after single acute ingestion and plot on ______ nomogram
Rumack-Matthew
Toxic effects of Acetaminophen:
- _____ _______ in 40%
- Renal failure : occurs in 20% of those with liver failure
- _______: MCly seen in children
- Centrolobular necrosis in 40%
- Renal failure: occurs in 20% of those with liver failure
- Vomiting : MCly seen in children
The following are the phases of what toxicity? After how many hours can you no longer prevent the patient from dying because the damage has already been done?
- 0-24 hours = N/V, pallor, diaphoresis, malaise, asymptomatic
- 24-48 hours = resolution of above and development of RUQ pain and ↑LFTs
- 72-96 hours = LFTs peak, coagulopathy, encephalopathy
- 4-14 days = recover or die
Acetaminophen Toxicity
8 hours
What is the antidote for acetaminophen toxicity? This has no benifit if > ____ hours postingestion
N-acetylcysteine (IV preferred over PO)
>8 hours
What is a toxic dose of acetaminophen?
140mg/kg
The following is a result of which toxicity?
- Resp. Alkalosis and ↓ed buffering capacity
- GI bleeding
- ↑temp.
- Metabolic acidosis
- Stimulates lipolysis–> ↑ketones and acidosis
- diaphoresis
Salicylate Toxicity
The following are signs and symptoms of what toxicity?
- Vomiting/ abdominal pain
- Met Ac w/ Resp Alk
- GI hemorrhage
- Heart failure
- Hypotension
- Prolonged bleeding time
- Agitation
- Lethargy
Salicylate Toxicity
The Done Nomogram is useful for single acute ingestion of _______ but is not used for liquid preparations, chronic use or enteric coated substances
salicylate
What are the 4 treatment options for Salicylate toxicity?
- Gastric lavage if within 1 hour of ingestion
- Mutlidose activated charcoal (every 4 hours)
- Normal saline at 2-3 x maintenance
- NaHCO3-
- +/- Hemodialysis (if renal failure, CNS toxicity, etc)
T/F: The anticonvulsant phenytoin can cause a false pos. for amphetamines on a drug screen
True
T/F: You cannot give Phenytoin with Dextrose containing IV fluid because it will precipitate
True
The following are signs and symptoms of which toxicity?
- Slurred speech
- Ataxia
- Nystagmus (horizontal)
- Visual changes
- Decreased LOC
- Hallucinations
- ↑ DTRs
- N/V
- Seizure (rare)
Anticonvulsant toxicity–>Phenytoin
What is the treatment for anticonvulsant toxicity (Phenytoin)?
- Supportive
- MDAC (multidose activated charcoal)
T/F: Carbamazepine (anticonvulsant) toxicity possesses antimuscarinic affects such as:
- Sedation
- Agitation
- Tachycardia
- Dilated pupils
- Ileus
- Urinary retention
- Dry skin
True
In addition to antimuscarinic effects, Carbamazepine (anticonvulsant) toxicity can cause hypotension, bradycardia and what 3 EKG findings?
QRS widening
Long PR
Long QT
What is the tx for Carbamazepine (anticonvulsant) toxicity?
- Supportive
- MDAC (multi dose activated charcoal)
The MCC of coma from overdose is from what?
Barbiturates (anticonvulsant) toxicity
The following are signs and symptoms of what toxicity?
- CNS depression
- Hypothermia
- Urinary retention
- Hypoglycemia
- Decreased motor activity
- Aspiration pneumonia (~40% of severe ingestions)
Barbiturate (anticonvulsant) toxicity
What is the treatment for Barbiturate (anticonvulsant) toxicity? (5)
- Supportive
- Glucose
- Narcan (won’t see response b/c not opioid)
- Charcoal
- Urinary alkalinization for long-acting preparations
What is important to check if you suspect someone has a valproate (anticonvulsant) toxicity) and what would you give them if it is positive?
Check ammonia
if increased and pt also has decreased LOC–> give carnitine
What are the 3 most common findings of valproate (anticonvulsant) toxicity?
- Drowsiness
- Confusion
- Mental status change
Most toxicity of which medication is related to the following drug-drug rxns:
- Haloperidol (major)
- ACE-I
- Caffeine
- Carbamazepine
- Clozapine
- Fluoxetine
- NSAIDs
- Phenytoin
- TCAs
Lithium Toxicity
The following are the clinical effects of which toxicity?
- Hand tremor
- fatigue
- decreased concentration
- polyuria
- anorexia with N/V/D
- rash
- seizure
Lithium toxicity
How do you treat Lithium toxicity? Which treatment is ineffective?
- Benzos for seizures
- Aggressive IV normal saline
- Hemodialysis for serum level >3.5mEq/L and little change in level after 6 hours of hydration
**No role for GI decontamination (charcoal ineffective)**
