Section 1 - Quiz Questions Flashcards
Peripheral vasoconstriction will slow the absorption of a drug administered by which route?
Peripheral vasoconstriction will slow the absorption of a drug administered by which route?
Subcutaneous
Three formulations of the same generic drug are bioequivalent if:
Three formulations of the same generic drug are bioequivalent if:
The areas under their plasma drug concentration x time curves are equal when they are given by the same route of administration.
Which statement about oral drug absorption is correct?
Drugs given orally to ruminants become concentrated in the alkaline fluids of the rumen and thus more readily absorbed in the intestine
Drugs that are weka bases are absorbed more rapidly than cidic drugs when they enter the gastric fluids of a cat
Most drugs are completely absorbed it he oral cavity when ingested
In dogs and cats, fat ingestion delays the absorption of basic drugs by slowing drug passage from stomach to the intestine
Which statement about oral drug absorption is correct?
Drugs given orally to ruminants become concentrated in the alkaline fluids of the rumen and thus more readily absorbed in the intestine
Drugs that are weka bases are absorbed more rapidly than cidic drugs when they enter the gastric fluids of a cat
Most drugs are completely absorbed it he oral cavity when ingested
In dogs and cats, fat ingestion delays the absorption of basic drugs by slowing drug passage from stomach to the intestine
True/False
Drug binding to albumin only occurs with neutral or weakly basic drugs
True/False
Drug binding to albumin only occurs with neutral or weakly basic drugs
**FALSE **
True/False
Abrupt increases in plasma drug concentrations are unlikely to occur as the result of sudden drug displacement from binding sites on plasma proteins because of rapid “free” drug elimination in vivo.
True/False
Abrupt increases in plasma drug concentrations are unlikely to occur as the result of sudden drug displacement from binding sites on plasma proteins because of rapid “free” drug elimination in vivo.
TRUE
True/False
The fraction of an acidic drug that is bound to alpha-acid glycoprotein is greater than to albumin
True/False
The fraction of an acidic drug that is bound to alpha-acid glycoprotein is greater than to albumin
FALSE
A drug given to a dairy cow is a weak base with a pKa = 8.8. Some of this drug appears in the cow’s milk (pH = 6.8). What is the ratio of ionized to non-ionized drug in her milk?
[HA]/[A-} or [BH+]/[B] = 10pKa-pH
A drug given to a dairy cow is a weak base with a pKa = 8.8. Some of this drug appears in the cow’s milk (pH = 6.8). What is the ratio of ionized to non-ionized drug in her milk?
[HA]/[A-} or [BH+]/[B] = 10pKa-pH
100:1
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
Drugs with a large Vd are less easily removed from the plasma by hemodialysis
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
Drugs with a large Vd are less easily removed from the plasma by hemodialysis
TRUE!
**Is this statement true/false regarding a drug’s volume of distribution (Vd)?
A drug must be widely and equally distributed throughout the body in order to have a large Vd **
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
**A drug must be widely and equally distributed throughout the body in order to have a large Vd **
FALSE
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
Drugs highly bound to plasma proteins typically have a large Vd
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
Drugs highly bound to plasma proteins typically have a large Vd
FALSE
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
Lipophilic, basic drugs have a smaller Vd than hydrophilic, acidic drugs
Is this statement true/false regarding a drug’s volume of distribution (Vd)?
Lipophilic, basic drugs have a smaller Vd than hydrophilic, acidic drugs
FALSE
Organ with the greatest surface area for drug absorption
Organ with the greatest surface area for drug absorption
Intestine
Organ with the greatest drug biotransformation activity
Organ with the greatest drug biotransformation activity
Liver
**Organ with the highest blood perfusion rate (ml blood/min per 100 gm weight) **
**Organ with the highest blood perfusion rate (ml blood/min per 100 gm weight) **
Kidneys
In which zone of the liver lobule are the enzymes for each drug biotransformation system more highly expressed?
1. Glucoronidation
**2. Microsomal Oxidation **
**3. Sulfation **
In which zone of the liver lobule are the enzymes for each drug biotransformation system more highly expressed?
**1. Glucoronidation - Zone 3 (centrilobular) **
**2. Microsomal Oxidation - Zone 3 (centrilobular) **
**3. Sulfation - Zone 1 (periportal) **
_True/False
regarding cytochrome P450 (mixed-function oxidase) system_
**Cytochrome P450 is located in liver microsomes and cytochrome P450 reductase is expressed in neighboring mitochondria **
_True/False
regarding cytochrome P450 (mixed-function oxidase) system_
**Cytochrome P450 is located in liver microsomes and cytochrome P450 reductase is expressed in neighboring mitochondria **
FALSE
_True/False
regarding cytochrome P450 (mixed-function oxidase) system_
**Cytochrome P450 enzymes function exclusively to biotransform drug molecules **
_True/False
regarding cytochrome P450 (mixed-function oxidase) system_
**Cytochrome P450 enzymes function exclusively to biotransform drug molecules **
FALSE
_True/False
regarding cytochrome P450 (mixed-function oxidase) system_
**Cytochrome P450 reductase mediates the transfer of electrons to heme iron in cytochrome P450 mono-oxygenases **
_True/False
regarding cytochrome P450 (mixed-function oxidase) system_
**Cytochrome P450 reductase mediates the transfer of electrons to heme iron in cytochrome P450 mono-oxygenases **
TRUE!
_True/False
Regarding the cytochrome P450 (mixed-function oxidase) system_
Monoamine oxidase and ethanol dehydrogenase are members of the cytochrome P450 enzyme superfamily
_True/False
Regarding the cytochrome P450 (mixed-function oxidase) system_
Monoamine oxidase and ethanol dehydrogenase are members of the cytochrome P450 enzyme superfamily
FALSE
Which domestic and wild animal pair is known to have a non-functional UDP-glucuronyltransferase gene?
Which domestic and wild animal pair is known to have a non-functional UDP-glucuronyltransferase gene?
House cat (Felius catus) and lion (Panthera leo)
Which process involves the deconjugation of a drug metabolite in the intestinal tract?
Which process involves the deconjugation of a drug metabolite in the intestinal tract?
Enterohepatic recycling
Which is the most common route of drug excretion?
Which is the most common route of drug excretion?
Urine
**Drugs that are bound reversibly to plasma albumin can enter the urine through: **
**Drugs that are bound reversibly to plasma albumin can enter the urine through: **
Active secretion
Which animal is the greatest excretor of drugs by the biliary route, based on its relative bile flow and ability to transport drugs into the bile that are in the 300-500 molecular weight range?
Which animal is the greatest excretor of drugs by the biliary route, based on its relative bile flow and ability to transport drugs into the bile that are in the 300-500 molecular weight range?
Rat
**The half-life of a drug will be shorter if there is a decrease in its: **
**The half-life of a drug will be shorter if there is a decrease in its: **
Volume of distribution
A drug with a half life of 7 hours is given at a fixed dose by constant rate intravenous infusion. In approximately how many hours will plasma concentrations of this drug first begin to plateau at a steady-state concentration?
A drug with a half life of 7 hours is given at a fixed dose by constant rate intravenous infusion. In approximately how many hours will plasma concentrations of this drug first begin to plateau at a steady-state concentration?
30 hours
True/False regarding drug administration and dosing
The loading dose, not the maintenance dose of a drug determines the plasma drug concentration at steady-state
True/False regarding drug administration and dosing
The loading dose, not the maintenance dose of a drug determines the plasma drug concentration at steady-state
FALSE
True/False regarding drug administration and dosing
**Increasing the rate of continuous intravenous drug infusion will shorten the time required to achieve a steady-state plasma drug concentration **
True/False regarding drug administration and dosing
**Increasing the rate of continuous intravenous drug infusion will shorten the time required to achieve a steady-state plasma drug concentration **
FALSE
True/False regarding drug administration and dosing
**The shorter a drug’s half-life is compared to its dosing interval, the greater the variability in plasma drug concentration (larger peak and trough) **
True/False regarding drug administration and dosing
**The shorter a drug’s half-life is compared to its dosing interval, the greater the variability in plasma drug concentration (larger peak and trough) **
TRUE
Which class of drug receptor best fits:
**Comprised of multiple protein subunits; its activation by ligands is associated with rapid changes in cell membrane potential **
Which class of drug receptor best fits:
Comprised of multiple protein subunits; its activation by ligands is associated with rapid changes in cell membrane potential
Ligand-Gated Ion Channel
Which class of drug receptor best fits:
An intracellular receptor that recognized lipid-soluble ligands and can bind to DNA
Which class of drug receptor best fits:
An intracellular receptor that recognized lipid-soluble ligands and can bind to DNA
Nuclear factor receptor
Which class of drug receptor best fits:
A single receptor protein that spans the cell membrane seven times
Which class of drug receptor best fits:
A single receptor protein that spans the cell membrane seven times
G Protein-Coupled Receptor
Which class of drug receptor best fits:
A single protein that spans the cell membrane once and has an intracellular catalytic domain which is unveiled when the receptor is activated by a ligand
Which class of drug receptor best fits:
A single protein that spans the cell membrane once and has an intracellular catalytic domain which is unveiled when the receptor is activated by a ligand
Kinase-Linked Receptor
**The therapeutic index of a drug is defined as: **
**The therapeutic index of a drug is defined as: **
The 50% lethal dose divided by the 50% effective dose
What is the mode by which most drugs are distributed in the body?
What is the mode by which most drugs are distributed in the body?
Passive Diffusion
**Enterohepatic recycling of a glucuronidated drug from the intestinal tract depends upon the presence of ________ in intestinal epithelial cells. **
**Enterohepatic recycling of a glucuronidated drug from the intestinal tract depends upon the presence of ________ in intestinal epithelial cells. **
B-Glucuronidase
An acidic drug with a pKa = 2.4 is given intravenously to a cat. What is the ratio of the protonated (non-ionized) to unprotonated (ionized) forms of the drug in the plasma?
An acidic drug with a pKa = 2.4 is given intravenously to a cat. What is the ratio of the protonated (non-ionized) to unprotonated (ionized) forms of the drug in the plasma?
1 : 100,000
What type of drug decreases the protency of an agonist by a surmountable mechanism?
What type of drug decreases the protency of an agonist by a surmountable mechanism?
Competitive Orthosteric Antagonist
**Name the drug biotransformation process that matches this statement **
Inactivation process for norepinephrine and other biogenic amine neurotransmitters
Name the drug biotransformation process that matches this statement
Inactivation process for norepinephrine and other biogenic amine neurotransmitters
Monoamine Oxidase
Name the drug biotransformation process that matches this statement
This process requires UDP-glucose
Name the drug biotransformation process that matches this statement
This process requires UDP-glucose
Glucuronic Acid Conjugation
Name the drug biotransformation process that matches this statement
Drug biotransformations occur through the chemical reduction of molecular oxygen and an iron atom
Name the drug biotransformation process that matches this statement
Drug biotransformations occur through the chemical reduction of molecular oxygen and an iron atom
Mixed-Function Oxidase System
Name the drug biotransformation process that matches this statement
A phase I biotransformation process that can be mediated by cytochrome P450 system or by enzymes expressed by gut bacteria
Name the drug biotransformation process that matches this statement
A phase I biotransformation process that can be mediated by cytochrome P450 system or by enzymes expressed by gut bacteria
Reduction
Name the drug biotransformation process that matches this statement
Pigs lack sufficient amounts of the cofactor needed to operate this phase II mechanism at a high level
Name the drug biotransformation process that matches this statement
Pigs lack sufficient amounts of the cofactor needed to operate this phase II mechanism at a high level
_Sulfate conjugation _
**Glucuronidation increases renal excretion of a drug molecule by active secretion through the ______ transport pathway into the renal tubule. **
**Glucuronidation increases renal excretion of a drug molecule by active secretion through the ______ transport pathway into the renal tubule. **
Acid (anion)
Drugs given to a lactating animal which are relatively _______ will tend to accumulate in her milk.
Drugs given to a lactating animal which are relatively _______ will tend to accumulate in her milk.
Basic
(Milk is slightly more acidic than plasma, and basic drugs would have a greater ionized fraction in this environment
What is the approximate half-life (in hours) of a drug who Vd = 143 L and clearance = 5 L/hr?
What is the approximate half-life (in hours) of a drug who Vd = 143 L and clearance = 5 L/hr?
20 hours
(Half life = 0.7 Vd/Cl)
_True/False _
The loading dose of a drug given by bolus injection is usually higher than the maintenance dose.
True/False
The loading dose of a drug given by bolus injection is usually higher than the maintenance dose.
TRUE
Drugs given to a pregnant animal which are relatively ______ will tend to accumulate more in the fetal circulation
Drugs given to a pregnant animal which are relatively ______ will tend to accumulate more in the fetal circulation
Basic
(Fetal blood is slightly more acidic than maternal blood, and acidic drugs would have a greater non-ionized fraction in this environment)
A drug has a half-life of 3 hours and is given at a total bolus dose of 10 mg, i.c. to a dog. Assuming that the drug is eliminated by first-order kinetics, in how many hours will the amount of drug in the dog’s body reach 2.5 mg?
A drug has a half-life of 3 hours and is given at a total bolus dose of 10 mg, i.c. to a dog. Assuming that the drug is eliminated by first-order kinetics, in how many hours will the amount of drug in the dog’s body reach 2.5 mg?
6 hours
**Bioavailability = **
**Bioavailability = **
Comparison of a drug’s plasma concentration vs. time relationships after its administration at a fixed dose by the intravenous route and an extravascular route
**Volume of distribution = **
**Volume of distribution = **
Measure of a drug’s theoretical dilution space in the body
**Bioequivalence = **
**Bioequivalence = **
Comparison of the plasma concentration vs. time relationships for two or more formulations of the same generic drug administered by the same route and dose
**Total Body Clearance = **
Total Body Clearance =
Rate at which a fixed volume of plasma is cleansed of a drug
