Pharmacokinetics Midterm Exam 1 Questions with Correct Answers

Pharmacokinetics Midterm Exam 1 Questions with Correct Answers



Question 1.
LECTURE 1: IV BOLUS: Pharmacokinetics

Correct Answer: the study of the process by which a drug is absorbed,
metabolized, and excreted by the body (what the body does to the drug).

Question 2.
Once absorbed, the drug first goes to the ____ via the ____

Correct Answer: liver; portal vein

Question 3.
If a drug is bound to albu-min, the drug is _____

Correct Answer: stuck, and cannot reach its target site. (TOO LARGE)

Question 4.
IV bolus injection

Correct Answer: ensures that 100% of the dose enter systemic circulation
(It skips the absorption phase) Bioavailability = 100%

Question 5.
One compartment model assumptions

Correct Answer: 1. T he body acts as a single homogenous compartment & drug
distributes uniformly in it
2. The drug is in rapid equilibrium between blood and the tis-sues
3. Changes in the plasma concentration of drug will result in proportional
in tissue drug levels
4. Blood compartment alone is sufficient to explain drug dispo-sition

Question 6.
Elimination follows a _______

Correct Answer: first order process

Question 7.
The elimination rate is pro-portional to ____________

Correct Answer: the concentration (or amount) of the drug in plasma

Question 8.
Elimination Rate Constant (Kel)

,Correct Answer: is the proportionality constant relating the rate of elimination
amount of drug in the body
it represents the fractional rate of drug loss from the body (% of drug
*No upper limit! A drug specific property (not dose!); has units of (time^-1)

Question 9.
Volume of distribution (Vd)

Correct Answer: The size of the compartment; it is a measure of drug
in the body Dose=Vd* Cpo Is estimated based on plasma drug conc., [drug] in
compartment = [drug] in the plasma It depends on physiochemical properties of
drug In most cases, it does not correspond to a physiologic volume, unless
to bloodstream or body water A drug specific property; units = mL or L

Question 10.
This is a parameter that helps us understand (drug-specific) relationship between amount
in the body (A) and the drug con-centration (C)

Correct Answer: volume of distribution (Vd)

Question 11.
If a drug (given at the same dose) show a different Cpo, why might this be?

Correct Answer: Different Vd amount the patient

Question 12.
Hydrophilic compounds have a _________ Cp0 than lipophilic given a dose

Correct Answer: Higher
- they do not cross lipid bilayers readily

Question 13.
Lipophilic compounds have a _________ Cp0 than a hy-drophilic compound given a dose

Correct Answer: Lower
-they have better tissue distribution

Question 14.
half life

Correct Answer: time it takes for half the drug in the body to be eliminated or
time it takes for the plasma conc. to decrease by half units: time Kel=ln(2)/t1/2

Question 15.
What is the fraction of the dose remaining in the body (i.e.. has not been eliminat-ed from
the body)

Correct Answer: e^(-kel*t)= or (1/2)^n where n=number of half lives has no
expressed as a percentage

, Question 16.
Kel of o.05 vs 0.2h-1 does what to drug elimination and half life?

Correct Answer: higher kel=shorter half life=concentration drops quickly
kel=longer half life=drug eliminated more slowly

Question 17.
Clearance (CL)

Correct Answer: the proportionality constant relating the rate of drug
and the plasma concentration CL = Vd * Kel = DOSE * F/AUC It is the volume of
plasma from which the drug is completely cleared per unit of time
**has upper limit! (can't exceed CO)
units: mL/min L/h

Question 18.
What does it mean when the Kel of drug A is GREATER than the Kel of drug B

Correct Answer: Drug A gets eliminated faster

Question 19.
What does it mean when the CL of drug A is GREATER than the CL of drug B

Correct Answer: Drug A gets eliminated faster

Question 20.
CL can never exceed ___________ ____________.

Correct Answer: cardiac output (because drugs reach the drug-elimination
such as kidney and liver via the blood pumped by the heart)

Question 21.
In linear kinetics, which pa-rameters are Independent of dose? (3)

Correct Answer: pharmacokinetic parameters are constant: k, CL Vd

Question 22.
For a drug that has linear ki-netics, if we double the dose then the plasma concentra-tion
will _______ at each time point

Correct Answer: Double (they're directly proportional)

Question 23.
In linear kinetics, which pa-rameters are DEPENDENT of the dose

Correct Answer: (Cp) plasma concentration at given time(t)

Question 24.