Tox-1 Flashcards
Xenobiotic
Foreign substance
Antidote
Any substance that prevents/relieves the effects of a toxicant (no antidote works on all toxicants)
NOAEL
No Observed Adverse Effect Level; the highest experimental point that is without adverse effect
LOAEL
Lowest Observed Adverse Effect Level; the lowest concentration or amount of a substance that causes an adverse effect experimentally
Additive
The sum of the effects of the chemicals involved in the reaction
Antagonistic
When the net effect of the chemical reaction is zero (antidotes for poisons)
Synergism
When the sum of the effects is more than each chemical individually
Cats are deficient in this type of metabolism
Glucuronidation
Dogs are deficient in this type of metabolism
Acetylation
Pigs are deficient in this type of metabolism
Sulfation
Bioactivation
When metabolism increases the toxicity of a compound
These three conditions make patients candidates for intubation
Unconscious, paralyzed, and severe respiratory distress
Ventilation may be needed if there is…
Hypoventilation and hypercapnia, metabolic acidosis, or hypoxia
At what concentration of oxygen do you treat hypoxia?
40%
What are three cardiovascular signs of toxicity?
Tachycardia, arrhythmias, and hypertension
What two drugs were mentioned that can be used to treat toxicity-associated tachycardia and arrhythmias?
Lidocaine and propranolol
What two drugs were mentioned that can be used to treat toxicity-associated hypertension?
Nitroprusside and Hydralazine
What are two CNS signs of toxicity?
Hyperactivity (seizures) and depression
What three drugs were mentioned that can be used to treat toxicity-associated CNS hyperactivity (seizures)?
Diazepam (GABA modulator), Phenobarbital, and Methocarbamol
What drug was mentioned that can be used to treat toxicity-associated CNS depression (decreased respiratory rate)?
Doxapram
What are the four major themes of the complete history for a patient presenting with a potential toxicity?
Health history, current clinical, environment, diet
What are the two most common methods of GI decontamination?
Emesis and activated charcoal
What is the goal of inducing emesis after a suspected toxic exposure?
Prevent toxicant absorption
Within how much time is inducing emesis successful in preventing toxicant absorption?
60 minutes
What are the contraindications of inducing emesis?
Too long, chronic exposure, caustic material, recent gastric sx, some species, oils/gasoline
What is the rule of thumb for when to induce emesis?
Toxic dose of the substance was ingested, no vomiting has yet occurred, and activated charcoal is not an option
What is the goal of using activated charcoal after a suspected toxic exposure?
Prevent toxicant absorption
What are the contraindications of activated charcoal?
Corrosive agents (acids, alkaloids), oil/gas, cyanide, obstructed airway/altered state, ruptured intestinal wall, chronic exposures
What is the rule of thumb for when to use activated charcoal?
Substance is known/thought to be adsorbed by it, ingestion was very recent/undergoes enterohepatic circulation/is sustained released, can tolerate it, and there is no immediate need to administer oral meds
What substances are not adsorbed by activated charcoal?
Acids, alkalis, alcohols/glycols, metals, oils, petroleum distillates, detergents
What is the goal of administering cathartics after a suspected toxic ingestion?
Facilitate toxicant removal
What are examples of cathartics?
Mineral oil, saline cathartics (milk of magnesia)
For corrosives, strong acids or bases, use ___ instead of emesis
Dilution with milk, water, or eggs
Lipid infusion is a relatively new treatment and is specifically used in _____ toxicosis
Ivermectin
What are the common names of organophosphate pesticides?
Parathion, malathion, chlorpyrifos
What is the mechanism of activity of organophosphate pesticides?
Irreversible inhibition of acetylcholine esterase (AChE) activity (anticholinesterase)
What are the clinical signs of organophosphate pesticide toxicity?
Muscarinic (SLUDGE-M), nicotinic (muscle fasciculations beginning with the face, generalized tremors, weakness, paralysis), CNS (depression, ataxia, nervousness, seizures)
How do you diagnose organophosphate pesticide toxicity?
Atropine challenge
If you observe dry mouth, mydriasis, and increased heart rate after an atropine challenge during a suspected organophosphate pesticide toxicity, what do you conclude?
Toxicity is NOT due to AChE (not OP toxicity)