Exam Practice Qs Flashcards
Which of the following statements is the closest description of Phase I metabolism?
A. Reactions which add a polar molecule to a functional group already present on a drug or one of its metabolites.
B. Reactions which occur in the blood supply.
C. Reactions which add a non-polar functional group to a drug.
D. Reactions catalyzed by cytochrome P450 enzymes, which introduces a hydroxyl group.
D
A drug has a Vd of 42,000 L. The drug is most likely:
A. Concentrated in the vascular compartment
B. Perferentially distributed to the brain
C. Highly concentrated in the muscle and fat
D. Distributed in the total body water
C
A patient changed the location of the transdermal patch to a skin area that was twice as thick as the original site of application. Using Fick’s Law of Diffusion, how will the flux be affected?
A. It will double
B. It will quadruple
C. It will halve
D. It will quarter
C
Nortriptyline is a tricyclic antidepressant used to treat clinical depression. CYP2D6 is the primary metabolic enzyme that converts nortriptyline to 10-hydroxynortriptyline. Genetic polymorphism of this enzyme in a patient population can result in variation of its pharmacokinetic parameters. A decrease in absorption of this drug and increase in its metabolite formation may be a result of:
A. The CYP2D6 enzyme undergoes gene deletion.
B. The CYP2D6 enzyme undergoes gene duplication.
C. The CYP2D6 enzyme undergoes alternative splicing resulting in an inactive enzyme.
D. The CYP2D6 enzyme is unstable.
B
The following statement regarding Bio-pharmaceutics Classification System (BCS) is FALSE:
A. The BCS is a scientific framework for classifying drug substances based on their aqueous solubility and intestinal permeability for immediate release drugs.
B. BCS defines a “highly soluble” drug that dissolve readily in 800mL of aqueous media from pH 1.2 to 7.5.
C. BCS defines drug substances as “highly permeable” when the extent of absorption in humans is greater than 90% of an administered dose.
D. BCS system is a logical categorization of drug molecules based on physio-chemical properties for better assessment of product-to-product bioequivalency.
B
The patient related factors that impact bioavailability of drugs include
A. Time of drug administration by the patient relative to the meals
B. Age, weight, disease state, gastrointestinal physiology and/or abnormal genetic characteristics
C. Compliance of patients with instructions of the physician, pharmacist, or nurse
D. All of the above
D
The most commonly occurring variant in the human genome is
A. Single-nucleotide polymorphism
B. Premature stop codon
C. Defective gene splicing
D. Nucleotide base insertion
A
Class I immediate release drugs, under the BCS classification, are categorized as high permeability and high solubility; therefore, they are eligible for a biowaiver application to the FDA.
A. True
B. False
A
Pharmaceutical Equivalence is defined by the FDA as:
A. The drug products that contain identical amounts of the identical active drug ingredient (i.e. the same salt or ester), in identical dosage forms but not necessarily containing the same inactive ingredients.
B. The drug products that contain the identical therapeutic moiety or its precursor but not necessarily in the same amount or dosage form or as the salt or ester.
C. The drug products that show similar rate and extent of absorption when administered at the same molar dose of the therapeutic moiety under similar experimental conditions, either single dose or multiple dose.
D. None of the above.
A
Drug elimination encompasses both:
A. Metabolism and excretion
B. Metabolism and biotransformation
C. Absorption and metabolism
D. Metabolism and distribution
A
Which of the following statements about tubular reabsorption is false?
A. Tubular reabsorption depends on the pH of the urine
B. Highly ionized drugs tend to remain in the urine
C. Tubular reabsorption can only be an active transport process
D. A and C
E. B and C
C
Which of the following is true concerning non-linear elimination kinetics (Michaelis Menten Kinetics)?
A. The elimination half-life, t1/2, decreases with increase dose.
B. The elimination rate constant, k, increases with increase dose.
C. At low doses (below saturation), the t1/2, Vd, and k remains the same.
D. Volume of distribution (Vd) and total plasma clearance (Clp) remains the same with
increases in dose.
E. All of the above are false.
C
Which is not a method for determining that a drug follows nonlinear PK?
A. The AUC rises disproportionally to the dose given
B. The half-life changes when a different dose is given
C. Calculations of F, Cl, and Vdss change with changing doses
D. The lack of superposition of drug concentrations to steady state occurs when dosing to steady state
E. None of the above
E
Which of the following may cause nonlinear PK to occur for a drug?
A. Saturable metabolism
B. Saturable protein binding
C. Enterohepatic cycling
D. Blood flow limited hepatic cellular uptake
E. All of the above may cause nonlinear PK
E
Renal failure has what effect of total volume of distribution?
A. Vd increases for drugs that are highly protein bound
B. Vd remains the same due to no changes in total body water
C. Vd decreases due to the loss of protein from the body
D. Vd decreases initially due to a decrease of total body water but increases later due to a build up of water because the body cannot remove water efficiently any longer
E. None of the above
A
