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Fundies test 4
12/12 toxicology
30
Dentistry
Graduate
12/12/2013

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Cards

Term
What metal has no known necessary physiological role in the body, can be ingested or inhaled, and binds to hemoglobin?
Definition
Lead (may be asymptomatic but there is no level of lead that is acceptable)
Term
true or false:

2 compounds having the same LD50 will have the same dose response curve
Definition
False

2 compounds can have same LD, doesn’t mean that they will have the same dose response curve
Term
True or false:

The lethal dose affecting the population is true for all individuals
Definition
False

For individuals, LD may be different, but if you look at population you will get even distribution. You should consider that when talking about toxic effects, there is a lot of interpatient variability
Term
What is the equation for therapeutic index?
Definition
lethal dose 50 / effective dose 50
Term
What is the shape of the dose-response for essential minerals and vitamins?
Definition
U-shaped (too much or too little vitamins and minerals is bade for you)

need to consider if a drug is a linear or U-shaped dose response
Term
What is one of the major causes of liver toxicities in the US?
Definition
acetaminophen, Tylenol (therapeutic index is not that big; fairly toxic)
Term
Toxicity is (disproportional or proportional) to exposure?
Definition
Toxicity proportional to exposure:
local vs systemic
Immediate vs delayed
Reversible vs irreversible
Term
*What is most frequently affect in systemic toxicity?
Definition
CNS
Term
Most poisons are (unintentional or intentional)?
Definition
unintentional (85%)

environmental exposures, occupational exposures, therapeutic drug errors, misuse of a substance, bites and stings, food poisoning
-Therapeutic errors – 10.5% of total exposures
Term
Where do exposures usually occur?

Is it mostly (acute or chronic) exposures?
Definition
90% occur at home

91% acute
Term
What age do most human exposures occur in?
More in boys or girls?
How do most exposures occur?
Definition
53% of human exposures involve children under the age of 6
Evenly divided by gender
Nearly 80% occur by ingestions
Term
Of the following poisons that are associated with the largest number of human fatalities, which ones usually occur together?

Cocaine
Opiods (Morphine, Heroin, Codeine)
Benzodiazepines [diazepam, Xanax (alprazolam)]
Acetaminophen
Cardiovascular drugs [Beta blockers (propranolol), Calcium Channel Blockers]
Alcohol
Antidepressants (Zoloft, Celexa, Prozac, Lexapro)
Definition
alcohol and antidepressants
Term
What is the treatment approach for acute poisoning?
Definition
ABCDE

Airway
Breathing
Circulation
Disability (CNS dysfunction)
Exposure
Term
How do you decrease absorption of the poison?
Definition
Enhance elimination by

induce vomiting with ipecac syrup
Gastric lavage (stomach pumping)
Activated charcoal, oral suspension, large surface area for adsorption of organic compounds
Cathartic (laxative) agents
hemodialysis
antidote(s)
Term
What is the leading cause of death due to poison in the US?
Definition
Carbon monoxide poisoning (unintended-CO is odorless, colorless)

hospitals generally do not measure blood CO level
Term
How does carbon monoxide poison people cellularly?
Definition
Carbon monoxide has a higher affinity for hemoglobin than oxygen and forms carboxyhemoglobin --> oxygen depletion
Term
How does carbon monoxide affect people's organs?
Definition
With moderate CO exposure, breathing remains normal
Gradual hypoxia causes vasodilation which increases cardiac output
Fainting occurs more often than difficulty breathing

(takes very little CO to cause symptoms)
Term
What is a clue in diagnosing someone with carbon monoxide poisoning?
Definition
cherry-red color of Hb(CO), pink skin
Term
A patient has bright red venous blood: increased saturation of Hb with O2; O2 not utilized in tissues, less unloading of O2 from Hb, oil of bitter almonds odor; difficulty breathing, irregular heartbeat, uncontrolled movement, convulsions, coma

What poisoning would you suspect?
Definition
cyanide poisoning?
Term
How would you treat cyanide poisoning?
Definition
Administer antidote(s) - Sodium nitrite and sodium thiosulfate to compete with cytochrome oxidase for cyanide and eliminated, then gastric lavage if ingested

(death in seconds to minutes due to respiratory arrest)
Term
**Methanol is converted to _________ by alcohol dehydrogenase which causes?
Definition
formic acid'

blindness, metabolic acidosis, coma, death
Term
*Overdose of acetaminophen causes ______ by being modified by _______
Definition
liver failure

CYP
Term
*How would you treat an overdose of acetaminophen?
Definition
increase production of glutathione
Term
Where is arsenic metabolized and eliminated?
Definition
Toxicity proportional to accumulation in the body: metabolized in the liver and eliminated mostly in urine
Term
Where are arsenic levels a major concern?
Definition
in well water
Term
If a patient has abrupt onset of gastroenteritis (pain, nausea, vomiting, diarrhea); hypotension and metabolic acidosis, Muscle weakness & aching; edema; renal & liver damage; “pins & needles” with stocking-glove distribution, and small "corns" on their palms, what type of poisoning do you suspect this person to have?
Definition
Arsenic poisoning
Term
*How do you treat arsenic poisoning?
Definition
chelation therapy with succimer
Term
*How do you treat lead poisoning?
Definition
succimer (same to treat arsenic)

Thiol group will chelate heavy metals
Term
How would you diagnose someone for lead poisoning?
Definition
blood levels of lead (and also affects CNS-clumsiness, falling, etc.)
Term
Why is succimer effect in treating metal poisoning?
Definition
Does not release metal in urine

Does not increase excretion of essential metals,
e.g., Zn, Cu, Fe

Does not enter cells
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