Midterm Flashcards
The ability of a substance to cauce harmful effects is referred to as:
- toxicity
- hazard
- side effect
- therapeutic effect
toxicity
The individual credited with recognizing the concept of Dose-Response relations is
- Hippocrates
- Galen
- Paracelsus
- Orfila
Paracelsus
Which of the following is a major target organ for the toxic effects of ingested chemicals?
- Brain
- Kidney
- Bone marrow
- Liver
Liver
The amount of a substance that shows up in the blood stream is known as the:
- exposure does
- toxic does
- therapeutic does
- absorbed dose
absorbed dose
Which of the following is/are correct regarding fractioning a total dose?
- intensity of toxic effects will decrease
- intensity of the therapeutic effect will increase
- intensity of the side effects will increase
- A and B are correct
- All are correct
intensity of the toxic dose will decrease
When extrapolating animal data to apply to humans, the most common Safety Factor used is:
- 1
- 10
- 100
- 1000
10
The minimal dose at which a toxic effect first appears is known as the:
- toxic dose
- absorbed dose
- effective dose
- lethal dose
toxic dose
The quantity of a substance administered to an individual over a period of time is known as:
- exposure dose
- absorbed dose
- therapeutic dose
- total dose
total dose
Which of the following is NOT correct regarding knowledge of the Dose-Response relationship for a chemical?
- the threshold doses for each the chemical’s effects can be determined
- the rate of buildup of the effects with increasing doses can be determined
- the degree of metabolism and storage of the chemical in the body can be determined
- the therapeutic index can be determined
the degree of metabolism and storage of the chemical in the body can be determined
The margin of safety for a therapeutic chemical is determined by which of the following ratios?
- LD50/ED50
- LD1/ED99
- ED99/LD1
- ED50/LD50
LD1/ED99
Therapeutic agents that are considered to be relatively safe and therefore have no need for monitoring have Therapeutic Indices:
10
> 10
The route of exposure that has the greatest potential for toxic effects upon accidental overdose is:
- inhalation/respiration
- intravenous injection
- intramuscular injection
- ingestion/GI
intravenous injection
Which of the following factors is the MOST important determinant of the intensity of toxic effects?
- target site concentration of the chemical
- gender of the individual exposed to the chemical
- age of the individual exposed to the chemical
- body weight of the individual exposed to the chemical
target site concentration of the chemical
The unintentional route of exposure to chemical that produces the fastest effects is which of the following?
- GI exposure
- Dermal exposure
- Inhilation exposure
Inhilation exposure
Which of the following is NOT correct regarding the role of the liver in chemical toxicity?
- Hepatic bio transformation generally reduces toxicity
- liver enzymes never cause an increase in toxicity
- the detoxication process generally results in forming hydrophilic metabolites
- The liver is a major target organ for toxicity for ingested chemicals
liver enzymes never cause an increase in toxicity
Lipophilic chemicals (ie DDT) are preferentially distributed from blood into which of the following storage tissues?
- adipose
- brain
- bone
- liver
adipose
Which of the following categories includes chemicals that will not cause toxic effects at any dose level?
- prescription meds
- non-prescription meds
- vitamins
- health supplements
- non of the above are correct
None of the above are correct
ANY substance can be toxic depending on the dose
Which of the following routes of exposure will cause the greatest magnitude of a toxic effect?
- intravenous injection
- intramuscular injection
- dermal exposure
- ingestion
intravenous injection
The undesired effects that are produced when the dose of a medication is within the recommended dose range are referred to as:
- lethal effects
- toxic effects
- side effects
- therapeutic effects
side effects
Majority of medications, particularly those marketed the over-the-counter (OTC) have a therapeutic index of
>10
5-10
1-5
> 10
In general, the ability of any chemical to produce systemic (non local) toxic effects is primarily dependent on which of the following factors?
- amount of detoxification enzymes in the liver
- thickness of the stratum corneum
- concentration of free chemical in plasma
- volume of urine output over 24 hours
concentration of free chemical in plasma
Which of the following will most likely cause the intensity of a toxic effect to decrease?
- reducing the thickness of skin by having
- decreased distribution to adipose tissue
- reducing water intake
- increasing liver enzyme activity by smoking
increasing liver enzyme activity by smoking
When a toxic effect manifests following several years of exposure to a chemical the effect is known as:
- acute toxicity
- subacute toxicity
- subchronic toxicity
- chronic toxicity
chronic toxicity
The major difference between acute and chronic toxicity is:
- acute toxicity occurs after a single dose whereas chronic toxicity occurs after multiple doses
- the target organs for toxicity are different
- acute toxicity appears soon after exposure whereas chronic toxicity occurs many months or years later
- acute toxic effects are unpredictable whereas chronic toxic effects are predictable.
acute toxicity appears soon after exposure whereas chronic toxicity occurs many months or years later
Toxic effects are most likely to be produced in the age group between: 20-40 40-50 50-70 70-75
70-75
What are the important factors that influence the degree of toxicity of a substance?
- innate chemical activity and dosage of the chemical
- rates of absorption
- exposure route, biological factors, and presence of other chemicals
- All of the above influence the degree of toxicity of chemicals
All of the above influence the degree of toxicity of chemicals
The use of antibiotics to manage infections with minimal damage to human tissues is based upon:
- differences in absorption if the antibiotic between bacteria and humans
- faster excretion of the antibiotic by humans
- greater bio activation
- selective toxicity of the antibiotic to bacteria
selective toxicity of the antibiotic to bacteria
Which of the following are the 2 general types of toxic effects?
- carcinogenic and teratogenic effects
- systemic and specific target organ effects
- hepatic and nephrotoxic effects
- central and peripheral nervous system effects
systemic and specific organ effects
Antagonism refers to an interaction in which:
- a chemical produces less toxicity in the simultaneous presence of another chemical
- toxicity produced by the combined presence of 2 chemicals is equal to the sum of their individual toxicities
- there is an increase in the toxicity due to the presence of the second chemical
- None of the above correctly describe antagonism
a chemical produced less toxicity in the simultaneous presence of another chemical
A chemical that causes a change in the DNA of a cell is a
- teratogen
- carcinogen
- mutagen
- androgen
mutagen
A dose of 4mg of an insecticide causes 20% toxicity whereas the same dose of another insecticide produces 30 % toxicity. If 8mg of a formulation containing equal concentrations of the 2 insecticides causes 50% toxicity, the interaction is known as:
- additivity
- antagonism
- synergism
- potentiation
Additivity
The use of 100% oxygen to manage carbon monoxide poisoning is an example of _____ antagonism.
- physiological
- chemical
- dispositional
- receptor
receptor
The usual dosage unit that incorporates the amount of material administered or absorbed in accordance with the size of the individual over a period of time is:
- ppm/hr
- mg/kg/day
- kg/100 lbs/week
- mg
mg/kg/day
The ED60 represents:
- the effect level of resulting from a threshold dose of 50mg
- the point at which 50% of the liver is destroyed
- the estimated dose that produces that desired effect at a 50% rate
- the median lethal dose
The estimated dose that produces that desired effect at a 50% rate
T/F
Every chemical can produce more than 1 biologic effect
True
T/F
The CNS is a target organ for all toxic chemicals
False
T/F
Dehydration will increase the intensity of toxic effects
True
T/F
Lowering adipose content as part of weight loss program can increase the intensity of toxic effects of lipophilic chemicals
True
T/F
Only the free form of a chemical in plasma can cause biologic effects
True
T/F
Renal dysfunction can decrease intensity of toxic effects
False
T/F
Liver damage will increase the percentage of a chemical in plasma that is bound to albumin
False
**would increase free form chemical
T/F
Chemicals that undergo hepato-biliary excretion in addition to urinary excretion can be expected to have a relatively shorter duration of effects compared to chemicals that undergo only urinary excretion.
False
T/F
Methemoglobinemia is characterized by “chocolate cyanosis” or arterial blood
True
** nitrogen oxides decrease transport of O2
T/F
Carbon monoxide has the smell of bitter almonds
False
**odorless and tasteless
T/F
Nitrous oxide is a dental anesthetic that can cause methemoglobinemia
True
** nitrogen oxides decrease transport of O2
T/F
The enzyme that detoxifies superoxide anion in the body is catalase
False
**reductase
T/F
Activation of molecular oxygen form “reactive oxygen species” is catalyzed by lead ions.
False
**lipid peroxidation, Fenton Rxn, Fe2+
T/F
Hydration of the stratum corneum will decrease the toxic effects of chemicals that are absorbed through the skin
True
T/F
Inhibition of acetylcholinesterase will cause skeletal muscle relaxation and sinus tachycardia
False
** inhibiting ACh-esterase causes contraction and inability to relax
(i think tachycardia is true tho)
T/F
Lead poisoning can cause iron-deficiency-like anemia, basophilic stilling, and GI cramps
True
