QUIZLET Unit 3 - Pharmacokinetics Flashcards
pom75
Volume of distribution measures the apparent space in the body available to contain the drug.
T/F
true
Hepatic elimination on bioavailability.
first pass effect
most convenient route
oral
route of administration that is Usually very slow absorption
transdermal
Reflect the time required for the drug to distribute from plasma to the site of action.
delayed
Also known as nonlinear elimination.
capacity-limited
Drug effects that are directly related to plasma concentration.
immediate
Type of effect seen for almost all drugs.
Immediate Effects
Delayed Effects
Cumulative Effects
All of the given
None of the given
delayed
route of administration that may be painful
intramuscular, subcutaneous
changes in drug effects are often delayed in relation to changes in ______ ______
plasma concentration
t/f “Pharmacokinetics governs the concentration-effect part of the interaction, whereas pharmacodynamics deals with the dose-concentration part.”
false
t/f
The standard dose of a drug will be suitable for all patients.
false
Pharmacokinetic variable/s.
clearance
volume of distribution
both
neither
both
“At steady state, the dosing rate (rate in) must equal the rate of elimination (rate out)”
maintenance dose
Calculated from the dose divided by the AUC.
clearance
t/f “Drugs absorbed from suppositories in the lower rectum enter vessels that drain into the inferior vena cava, thus bypassing the liver.”
true
t/f
“At concentrations that are high relative to the Km, the elimination rate is almost independent of concentration, a state of pseudo-zero order elimination.”
true
“Blood flow to the organ is the main determinant of drug delivery, but plasma protein binding and blood cell partitioning may also be important for extensively bound drugs that are highly extracted.”
true
true or false
The ratio of the rate of elimination of the drug compared to the plasma drug concentration defines volume of distribution.
false
clearance toh!!!
80 to 100% Bioavailability.
Oral
IV
IM
SC
Transdermal
transdermal
Just enough drug is given in each dose to replace the drug eliminated since the preceding dose.
Maintenance dose
Loading dose
Both
neither
maintenance dose
Also known as saturable elimination.
capacity-limited elimination
t/f
Volume distribution is the ratio of the amount of the drug in the body compared to the plasma concentration
true
type of dose wherein The volume of distribution is the most important proportionality factor.
Maintenance dose
Loading dose
loading dose
Greater when administered as a constant infusion than with intermittent dosing.
none of the given
The measure of the apparent space in the body available to contain the drug.
volume of distribution
Due to the slow turnover of a physiologic substance that is involved in the expression of the drug effect
delayed effects
t/f Systemic clearance is affected by bioavailability.
false
t/f “The standard dose of a drug is based on trials in healthy volunteers and patients with the average ability to absorb, distribute, and eliminate the drug.”
TRUE
Volume of distribution is the ratio of the amount of the drug in the body compared to the plasma concentration
True
False
true
Also known as concentration-dependent elimination
capacity limited elimination
Determined by the site of administration and the drug formulation.
rate of absorption
75 to ?100% Bioavailability.
sc, im
The factor that predicts the rate of elimination in relation to the drug concentration
Clearance
Volume of distribution
both
neither
clearance
Less first-pass effect than oral.
rectal
Most rapid onset
Intravenous (IV)
Intramuscular (IM)
Subcutaneous (SC)
Oral (PO)
Rectal (PR)
Inhalation
Transdermal
Intravenous (IV)
Drug effects that are directly related to plasma concentrations
Immediate Effects
Delayed Effects
Cumulative Effects
All of the given
None of the given
Immediate Effects
Also known as mixed-order elimination.
capacity limited elimination
flow limited elimination
both
neither
capacity limited elimination
t/f
“Suppositories tend to move upward in the rectum into a region where veins that lead to the liver predominate, thus only about 50% of a rectal dose can be assumed to bypass the liver.”
true
“The pharmacokinetic processes of absorption, distribution, and elimination determine how rapidly and for how long the drug will appear at the target organ.”
True
False
false
The hepatic first-pass effect can be avoided to a great extent by, EXCEPT “
Sublingual tablets
Transdermal patches
Rectal suppositories
Oral tablets
Oral tablets
Effective drug concentration is the drug that reaches the systemic circulation.
True
False
true
Drug elimination pathways when blood flow to an organ does not limit elimination.
capacity limited elimination
flow limited elimination
both
neither
capacity limited elimination
Target Concentration Design for Dosage Regimen
Maintenance Dose
Loading Dose
both
neither
both
time it takes for the amount of the drug falls to half of the earlier measurement is known as
Steady state concentration
Dosing regimen
Half-life
Elimination time
Half-life
The measure of the ability of the body to eliminate the drug
Clearance
Volume of distribution
Half-life
Bioavailability
Clearance
t/f
Males metabolize drug faster than females
true
attacks the heme
Enzyme inducer
Enzyme inhibitor
Enzyme inhibitor
classified as suicide inhibitors
Enzyme inducer
Enzyme inhibitor
Enzyme inhibitor
reduces rate of degradation of p450 enzymes
Enzyme inducer
Enzyme inhibitor
Enzyme inducer
Bioavailability is dependent on the following factors EXCEPT:
Extent of absorption
First pass effect
Site of administration
Elimination
Elimination
Blood cell partitioning is the main determinant of drug delivery, but plasma protein binding and blood flow to the organ may also be important for extensively bound drugs that are highly extracted
true/false
false
kasi BLOOD FLOW to the organ is the main determinant for drug delivery
true / false
“At concentrations that are high relative to the Km, the elimination rate is almost independent of concentration a state of first order elimination.”
false
affected by drug delivery as well as plasma protein binding and blood cell partitioning
Capacity limited elimination
Flow limited elimination
Both
Netiher
Flow limited elimination
Used for drugs with long half-lives
Maintenance dose
Loading dose
Both
neither
loading dose
- systemic clearance
- bioavailability
directly proportional
inversely proportional
no relation
no relation
Hyperthyroidism speeds up the metabolism of drugs
true
false
true
GOAL: Maintain a concentration higher than minimum
therapeutic level at all times
Maintenance dosage
Loading dosage
Maintenance dosage
hepatic first past effect is avoided to a greater extent in?
transdermal, sublingual tablets
drugs with _____ ______ ______ ratio have large 1st pass effect
high hepatic extraction ratio
major source of drug elimination
kidneys, liver
Drugs absorbed from suppositories in the lower rectum enter vessels that drain into the _______, thus bypassing the liver
inferior vena cava
rate if absorption is determined by?
site of administration
Plan for drug administration over a period of time
dosage regimen
fraction of the drug removed from the perfusing blood during passage to the organ
extraction
hepatic first past effect is avoided to a lesser extent in?
rectal suppositories
Dose needed to maintain a steady state of concentration
maintenance dose
Desired therapeutic effects are produced
dosage regimen
Maintain plasma concentration within a specified range over long periods of therapy
Maintenance dosage
Loading dosage
Maintenance dosage
For drugs with long half-lives and longer time to reach a steady state
Maintenance dosage
Loading dosage
Loading dosage
_______ is the most important parameter in defining rational drug dosage
clearance
More highly protein bound drug will displace the less protein bound drug
true or false
true
what is the plan for drug administation over a period of time
dosing regimens
Volume of distribution (Vd) is important
Maintenance dosage
Loading dosage
Loading dosage
Given to promptly raise the concentration of the drug to the target concentration
Maintenance dosage
Loading dosage
Loading dosage
Type of dose used for drugs with very long half-lives and longer time to reach a steady state
Maintenance dose
Loading dose
Loading dose
- rate of plasma drug concentration
- rate of elimination
directly proportional
inversely proportional
no relation
directly proportional
- rate of elimination
- rate of drug concentration
directly proportional
inversely proportional
no relation
inversely proportional
rate of infusion = rate of elimination
steady state
Which is important in loading dose?
Volume of distribution (Vd)
Clearance (CL)
Volume of distribution (Vd)
how much time does it take to reach steady state
4 half lives
acidic drugs bind to what type of plasma protein?
albumin
basic drugs bind to what type of plasma protein?
alpha 1 acid glycoprotein
Which is important in maintenance dose?
Volume of distribution (Vd)
Clearance (CL)
Clearance (CL)
Fraction or percentage of the drug removed from the perfusing blood during passage through the organ.
extraction ratio
How many percent of the drug is cleared after 4 half lives?
94%
Creatinine clearance is a good indicator of _____ function
renal
MTC determines the permissible ____ plasma concentration
peak
MEC determines the desired _____ levels of a drug given intermittently
trough