USMLE-like pharmacology quiz. Part 2: pharmacokinetics (drug movement and absorption)

The following are multiple choice questions in a style similar to those included in the USMLE step 1. The main topic here is: pharmacokinetics (drug movement and absorption). This quiz has been uploaded to Scribd by medical student James Lamberg. The correct answers can be found in link at the end of this post.

Note: the words underlined don’t mean right answer but link to another page.

2 – Pharmacokinetic Principles: Drug Movement
1) Pharmacokinetics is the effect of the ____ and pharmacodynamics is the effect of the ____.
a) Drug on a drug; Body on the drug
b) Body on the drug; Drug on a drug
c) Drug on the body; Body on the drug
d) Body on the drug; Drug on the body
e) Drug on a drug; Drug on a drug

2.1) Which of the following is NOT an action of the body on a drug?
a) Absorption
b) Distribution
c) Metabolism
d) Excretion
e) Side effects
3) If a drug is 80% bound to blood elements or plasma proteins, what part is considered the free form?
a) 20%
b) 40%
c) 50%
d) 80%
e) 100%
4.1) Which of the following describes minimal effective concentration (MEC)?
a) The minimal drug plasma concentration that can be detected
b) The minimal drug plasma concentration to enter tissues
c) The minimal drug plasma concentration to interact with receptors
d) The minimal drug plasma concentration to produce effect
e) The minimal drug plasma concentration to reach therapeutic levels
4.2) If a patient misses three doses of their daily drug, which of the following (in general) is the best solution?
a) Take a 4x dose at the next dose time
b) Wait 3 more days (week total) then return to normal regimen
c) Do nothing and continue normal regimen
d) Setup an appointment to have the patient evaluated
e) Prescribe a higher dosage pill so missed doses will have less effect
4.3) Blood levels of a drug correlate to the effectiveness of that drug, such as with
pentazocine (Talwin) or phenobarbitol (Luminal).
a) True
b) False
5.1) Which of the following drug permeation mechanisms involves polar substances too large to enter cells by other means, such as iron or vitamin B12?

a) Aqueous diffusion
b) Lipid diffusion
c) Carrier molecules
d) Endocytosis and exocytosis
5.2) Which of the following drug permeation mechanisms occurs across epithelial tight
junctions and is driven by a concentration gradient?
a) Aqueous diffusion
b) Lipid diffusion
c) Carrier molecules
d) Endocytosis and exocytosis
5.3) Which of the following drug permeation mechanisms uses the Henderson-
Hasselbalch equation for the ratio of solubility for the weak acid or weak base?
a) Aqueous diffusion
b) Lipid diffusion
c) Carrier molecules
d) Endocytosis and exocytosis
5.4) Which of the following drug permeation mechanisms is used for peptides, amino
acids, glucose, and other large or insoluble molecules?
a) Aqueous diffusion
b) Lipid diffusion
c) Carrier molecules
d) Endocytosis and exocytosis
5.5) Which of the following drug permeation mechanisms uses caveolae?
a) Aqueous diffusion
b) Lipid diffusion
c) Carrier molecules
d) Endocytosis and exocytosis
6.1) Using the Fick Law of Diffusion, how will flux change if membrane thickness is
doubled?
a) It will double
b) It will quadruple
c) It will halve
d) It will quarter
e) It will not change
6.2) Using the Fick Law of Diffusion, how will flux change if the permeability
coefficient is quadrupled?
a) It will double
b) It will quadruple
c) It will halve
d) It will quarter
e) It will not change
7.1) Which of the following is the amount of a drug absorbed per the amount
administered?
a) Bioavailability
b) Bioequivalence
c) Drug absorption
d) Bioinequivalence
e) Dosage
7.2) Which of the following is NOT needed for drug bioequivalence?
a) Same active ingredients
b) Same strength or concentration
c) Same dosage form
d) Same route of administration
e) Same side effects
7.3) For intravenous (IV) dosages, what is the bioavailability assumed to be?
a) 0%
b) 25%
c) 50%
d) 75%
e) 100%
7.4) Although morphine (Avinza, Oramorph SR, MS Contin) is well-absorbed when
administered orally (PO), how much of the drug is metabolized on its first pass through
the liver?
a) 90%
b) 70%
c) 50%
d) 30%
e) 10%
7.5) For a generic drug to be bioequivalent to an innovator drug (per FDA), it must be
measured in ____ of subjects to fall within ____ of the mean of the test population
bioavailability.
a) 50; 50
b) 80; 20
c) 20; 80
d) 95; 5
e) 5; 95
7.6) Using the FDA bioequivalence rule, how much variation could a generic drug
potentially have from an innovator and still be considered equivalent?
a) 100%
b) 20%
c) 40%
d) 60%
e) 80%
8.1) Which of the following is NOT a pharmacokinetic process?
a) Alteration of the drug by liver enzymes
b) Drug metabolites are removed in the urine
c) Movement of drug from the gut into general circulation
d) The drug causes dilation of coronary vessels
e) The drug is readily deposited in fat tissue
8.2) Which of the following can produce a therapeutic response? A drug that is:
a) Bound to plasma albumin
b) Concentrated in the bile
c) Concentrated in the urine
d) Not absorbed from the GI tract
e) Unbound to plasma proteins
8.3) Which of the following most correctly describes steroid hormones with respect to
their ability to gain access to intracellular binding sites?
a) They cross the cell membrane via aqueous pores
b) They have a high permeability coefficient
c) They are passively transported via membrane carriers
d) They require vesicular transport
e) Their transport requires the hydrolysis of ATP

3 – Pharmacokinetic Principles: pH and Drug Movement
1) Most drugs are either ____ acids or ____ bases.
a) Strong; Strong
b) Strong; Weak
c) Weak; Weak
d) Weak; Strong
2.1) Aspirin readily donates a proton in aqueous solutions and pyrimethamine readily
accepts a proton in aqueous solution. Thus, aspirin is a(b) ____ and pyrimethamine is
a(n) ____.
a) Acid; Base
b) Base; Acid
c) Acid; Acid
d) Base; Base
2.2) Given the equilibrium HA <=> A- + H+ (acid) and BH+ <=> B + H+ (base), in an
acid environment (low pH) the acid reaction will move to the ____ and the base reaction
will move to the ____.
a) Right; Left
b) Right; Right
c) Left; Right
d) Left; Left
3.1) What form of a drug is more lipid-soluble, and thus would remain trapped within a
compartment where the pH does not favor the lipid-soluble form?
a) Strong acid (A-)
b) Weak acid (A-)
c) Neutral (AH and B)
d) Weak base (BH+)
e) Strong base (BH+)
3.2) The lipid-soluble form of a base is ____ and the lipid-soluble form of an acid is
____.
a) Protonated; Protonated
b) Protonated; Unprotonated
c) Unprotonated; Unprotonated
d) Unprotonated; Protonated Pharmacology – Part 1 Quiz
Version: 16Oct2008 Page 8 of 42
4.1) If the pKa of Aspirin (acetylsalicylic acid) is 3.5 and the pH of the stomach is 2.5,
how much Aspirin is in the protonated species in the stomach and is this the amount
available for absorption?
a) ≈ 91%; Yes
b) ≈ 91%; No
c) ≈ 9%; Yes
d) ≈ 9%; No
4.2) What percentage of Aspirin would be ionized in the blood compartment (pH = 7.4)
assuming pH is 7.5 and Aspirin pKa is 3.5?
a) (10,000 – 1) / 1 = 99.99%
b) (100 – 1) / 1 = 99%
c) None
d) 1 / (100 – 1) = 0.9%
e) 1 / (10,000 – 1) = 0.009%
4.3) If the pH – pKa = -1, what percentage of weak base is nonionized?
a) 99
b) 90
c) 50
d) 10
e) 1
4.4) If the pH – pka = 2, what percentage of weak acid is nonionized?
a) 99
b) 90
c) 50
d) 10
e) 1
4.5) If pH > pKa, the drug is ____ and if pH < pKa, the drug is ____. An unprotonated
acid is ____ and a protonated base is ____.
a) Protonated; Unprotonated; Charged; Charged
b) Protonated; Unprotonated; Neutral; Neutral
c) Unprotonated; Protonated; Charged; Charged
d) Unprotonated; Protonated; Neutral; Charged
e) Unprotonated; Protonated; Charged; Neutral
5.1) Weak acids are excreted faster in ____ urine and weak bases are excreted faster in
____ urine.
a) Acidic; Alkaline
b) Alkaline; Acidic
c) Acidic; Neutral
d) Neutral; Alkaline
e) Alkaline; Neutral
5.2) A patient presents with an overdose of acidic Aspirin. The drug ____ can be given to
____ the pH of the urine and trap the Aspirin, preventing further metabolism.
a) NaHCO3; Increase
b) NaHCO3; Decrease
c) NH4Cl; Increase
d) NH4Cl; Decrease Pharmacology – Part 1 Quiz
Version: 16Oct2008 Page 9 of 42
5.3) A patient presents with an overdose of alkaline Codeine. The drug ____ can be given
to ____ the pH of the urine and trap the Codeine, preventing further metabolism.
a) NaHCO3; Increase
b) NaHCO3; Decrease
c) NH4Cl; Increase
d) NH4Cl; Decrease
6.1) The principle of drug manipulation for excretion of a drug out of the renal tubule can
be accomplished by:
a) Acidifying the urinary pH
b) Adjusting the urinary pH to protonate weakly acidic drugs
c) Adjusting the urinary pH to unprotonate weakly basic drugs
d) Adjusting the urinary pH to ionize the drug
e) By neutralizing the urinary pH
6.2) Aspirin is a weak organic acid with a pKa of 3.5. What percentage of a given dose
will be in the lipid-soluble form at a stomach pH of 1.5?
a) About 1%
b) About 10%
c) About 50%
d) About 90%
e) About 99%
6.3) For which of the following drugs is excretion most significantly accelerated by
acidification of the urine?
a) Weak acid with pKa of 5.5
b) Weak acid with pKa of 3.5
c) Weak base with pKa of 7.5
d) Weak base with pKa of 7.1
6.4) A patient diagnosed with type 2 diabetes is administered an oral dose of 0.1 mg
chloropropamide, an insulin secretagogue and weak acid with a pKa of 5.0. What is the
amount of this drug that could be absorbed from the stomach at pH 2.0?
a) 99.9 µg
b) 90 µg
c) 50 µg
d) 0.05 mg
e) 0.01 mg

4 – Pharmacokinetic Principles: Absorption
1) Bioavailability (F) is the fraction or percentage of administered drug that reaches the
systemic circulation via a given route as compared to what route?
a) Oral
b) IV (intravenous)
c) IO (intraosseous)
d) CSF (cerebrospinal fluid)
e) Whatever route attains the target drug concentration in plasma (CT)
2) What organ is responsible for metabolism in the “first pass effect”?
a) Brain
b) Heart
c) Kidney
d) Liver
e) Spleen
3.1) A patient is in the hospital and is stable on digoxin 0.175 mg IV qd (daily). How
much digoxin in mg. would you need to give your patient orally, given that the
bioavailability for oral digoxin tablets is 0.7?
a) (0.175 * 0.7) / (1.0) = 0.1225 mg
b) (0.175 * 1) / (0.7) = 0.25 mg
c) (0.175 + 0.7) / (1.0) = 0.875 mg
d) (0.175 + 1) / (0.7) = 1.67 mg
e) No change is necessary
3.2) Given a graph of plasma drug concentration versus time, what part of the graph
would be used to calculate bioavailability for a PO (oral) drug administration?
a) Maximum concentration
b) Steady concentration
c) Derivative of the curve (slope)
d) Integral of the curve (area underneath)
e) The curve is not used to calculate bioavailability
4.1) Which of the following routes of administration has a bioavailability of about 80-
100%, is usually very slow absorbing, and has prolonged duration of action?
a) IV (intravenous)
b) IM (intramuscular)
c) SQ (subcutaneous)
d) Rectal
e) Transdermal
4.2) Which of the following routers of administration is the most convenient, although
may have a bioavailability anywhere from 5-100%?
a) PO (oral)
b) IV (intravenous)
c) IM (intramuscular)
d) SQ (subcutaneous)
e) Transdermal
4.3) Which of the following enteral administration routes has the largest first-pass effect?
a) SL (sublingual)
b) Buccal
c) Rectal
d) Oral
4.4) Epithelial cells are connected by ____, which are tough to cross and materials often
must pass through the cells. Endothelial cells of blood vessels are connected by ____,
which proteins cannot cross but smaller drugs (MW 200-500) can.
a) Macular gap junctions; Tight junctions
b) Tight junctions; Macular gap junctions
c) Adherens junctions; Tight junctions
d) Tight junctions; Adherens junctions
e) Macular gap junctions; Adherens junctions
4.5) Which of the following administration routes is not often used, is painful, and has a
risk of infection and adhesion?
a) EPI (epidural)
b) IA (intraarterial)
c) IP (intraperitoneal)
d) IV (intravenous)
e) IO (intraosseous)
4.6) Which of the following is NOT an advantage of prolonged release medications?
a) Less frequent administration
b) Therapeutic effect overnight
c) Lower incidence of side effects
d) Patient compliance
e) More fluctuation in plasma concentration
4.7) What is the common location for the scopolamine motion sickness transdermal
patch?
a) Side of the hip
b) Chest
c) Over the deltoid muscle
d) Behind the ear
e) On the back of the neck

5 – Pharmacokinetic Distribution: Basics
1.1) Which of the following would receive drug slowly?
a) Liver
b) Brain
c) Fat
d) Muscle
e) Kidney
1.2) Which of the following is the least important for passage through capillary walls but
the most important for passage through the cell wall?
a) Molecular size
b) Lipid solubility
c) Diffusion constant
d) pH
e) pKa
1.3) Which of the following is the most important for movement through capillary walls?
a) Molecular size
b) Lipid solubility
c) Diffusion constant
d) pH
e) pKa
1.4) Which of the following locations would most trap a lipid soluble drug?
a) Blood
b) Intestines
c) Brain
d) Stomach
1.5) What type of drugs can cross the blood-brain barrier (BBB)?
a) Large and lipid-soluble
b) Large and lipid-insoluble
c) Small and lipid-soluble
d) Small and lipid-insoluble
2.1) Acidic drugs, such as phenytoin, bind primarily to which of the following plasma
proteins?
a) α1-fetoprotein (AFP)
b) GC Globulin
c) Albumin
d) α1-acid glycoprotein (AAG)
e) Transcortin
2.2) Basic drugs, such as lidocaine, bind primarily to which of the following plasma
proteins?
a) α1-fetoprotein (AFP)
b) Gc-Globulin (GcG)
c) Albumin
d) α1-acid glycoprotein (AAG)
e) Transcortin
3.1) A decrease in drug-protein binding will lead to which of the following?
a) Decrease in the unbound drug concentration
b) Increase in free drug
c) Increase in rate of drug elimination
d) Decrease in volume of distribution
3.2) A patient presents with acute-onset cirrhosis of the liver. They are found to have
hypoalbuminemia. In severe cirrhosis it is expected that AAG will be decreased, but the
patient presents with increased AAG due to the inflammatory response. Which of the
following is the most likely?
a) Increased acidic drug binding and increased basic drug binding
b) Increased acidic drug binding and decreased basic drug binding
c) Decreased acidic drug binding and increased basic drug binding
d) Decreased acidic drug binding and decreased basic drug binding
3.3) Which of the following is NOT a site of loss (where drug is not used)?
a) Fat
b) GI tract
c) Muscle
d) Site lacking receptors
4.1) Which of the following locations can accumulate lipid-soluble drugs, has little or no
receptors, and can hold distributed drugs like barbiturates?
a) Liver
b) Kidney
c) Brain
d) Fat
e) Fetus
4.2) Which of the following locations has high blood flow and is a site of excretion?
a) Liver
b) Kidney
c) Brain
d) Fat
e) Fetus
4.3) Anything affecting renal perfusion will affect drug delivery to the kidney, drug
excretion, and drug levels in the blood.
a) True
b) False
4.4) Which of the following can be treated with drugs due to a leaky area in the blood-
brain barrier near the medulla?
a) Seizures
b) Shivers
c) Diarrhea
d) Nausea
e) Vomitting
4.5) What is the approximate lag time for equilibration between maternal blood and fetal
tissues?
a) 20 mins
b) 40 mins
c) 1 hour
d) 2 hours
e) 6 hours
Match the body compartment with the volume, assuming a 70kg male patient:
5.1) Total body a) 4
5.2) Plasma b) 10
5.3) Interstitial c) 14
5.4) Extracellular d) 28
5.5) Intracellular e) 42
5.6) If protein plasma binding is decreased, how will volume of distribution be affected?
a) Increased
b) Decreased
c) Not changed
5.7) 400 mg of a drug is administered to a patient and the drug is later measured in
plasma to be 1 µg/ml. What is the apparent volume of distribution (Vd)?
a) 0.04 L
b) 0.4 L
c) 4 L
d) 40 L
e) 400 L
5.8) Elderly patients often have ____ muscle mass and thus a(n) ____ Vd.
a) More; Increased
b) More; Decreased
c) Less; Increased
d) Less; Decreased
5.9) Patients with ascites or edema would have ____ Vd for hydrophilic drugs, such as
gentamicin.
a) Increased
b) Decreased
c) Unchanged

Complete PDF file with answers

More USMLE pharmacology questions

Technorati : , ,

Illustrated Psychopharmacology Lectures in Your Inbox

  • Mechanisms of action, adverse effects and indications of psychotropic medications.
  • Concise and illustrated presentations. 
  • Practical tips for mental health professionals.

laptop2


 

 

Are you a visual learner interested in learning psychopharmacology? Click here to get our videos