Intro to Toxicology Flashcards
What is toxicology?
the study of adverse effects of chemical, biological, and physical agents on living systems
What are toxins?
toxic substances produced by biological systems such as plants and animals
What are toxicants?
toxic substances produced by human activities
What is toxidrome?
term for “toxicologic syndromes” - a group of signs and symptoms consistently associated with specific toxic agents
What is risk?
the expected frequency of the occurrence of an undesirable effect arising from exposure to a chemical or physical agent
What is hazard?
the ability of a chemical agent to cause injury in a given situation or setting
What is acute exposure?
a single exposure, or multiple exposures occurring over 1-2 days.
What is chronic exposure?
continuous of multiple exposures occurring longer than a few days
What are synergistic effects?
a greater than additive effect from exposure to two or more chemicals
What is potentiation?
a special form of synergism; when a chemical that itself produces no effect increases the toxicity of another.
What is therapeutic index?
ratio between the toxic dose and therapeutic dose of a drug
Example of very potent drug? What does this mean?
Botulinum toxin. lower dose is lethal.
example of less potent drug?
ethyl alchol. less potent but can still be lethal.
what’s important to note about dose and potency?
wide range, but all can be used safely. need to know dose AND potency to determine toxicity.
Where do we get info about toxicities (4)?
human studies, animal studies, in vitro studies, computer modeling
What should you be concerned with when treating poisoning?
ABC’s
What is the quick fix for hypoglycemia?
Dextrose
What is the quick fix to prevent Wernicke’s encephalopathy?
Thiamine
What is the quick fix opioid antagonist?
Naloxone
What is the quick fix benzodiazepine antagonist?
Flumazenil
what are some labs you should look at?
arterial blood gases, electrolytes, renal function, serum osmolality, ECG
What’s up with screening?
there are screening tests for certain classes of chemicals. broad screening is time-consuming, expensive, and generally ineffective. but specific measurements can be important in determining therapeutic approach and prognosis
how to decontaminate GI tract (5)?
1) emesis: syrup of ipecac
2) gastric lavage: risk vs. benefit?
3) activated charcoal: sometimes contraindicated
4) cathartics: can be given with charcoal to hasten elimination from bowel
5) whole bowel irrigation: oral solution, drug packers
4 ways to enhance elimination?
urinary pH manipulation (only works for a few chemicals), peritoneal dialysis (simple but inefficient), hemodialysis (more efficient), hemoperfusion (can remove low water solubility drugs)
3 mechanisms of antidotes?
1) bind to toxicant and inactivate it (e.g. chelators, antibody fragments for digoxin)
2) block critical receptors (e.g. naloxone, atropine for anticholinesterase agents)
3) change toxicant metabolism (e.g. ethanol for methanol, NAC for acetaminophen)
