Pharmaceutics Drug Disposition Practice Test

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• True or false: If a drug has an active metabolite, it is likely that plasma concentration does not correlate with response.
• Which option best defines 'site of absorption' in pharmacokinetics?
• How can you estimate the elimination rate constant (ke) and half-life (t1/2) from an IV concentration-time profile?
• Which of the following is an example illustrating that an endogenous compound can act as a xenobiotic?
• For intravenous administration, what is the bioavailability F?
• In a constant IV infusion, how does the concentration change over time?
• What characterizes nonlinear (saturable) pharmacokinetics, and can you name a classic drug example?
• Which equation best represents the relationship between ke and t1/2 in a first-order elimination process?
• If the concentration-time curve shows a decreasing trend, what does this indicate about the rates of absorption and elimination?
• What is the site of administration in pharmacokinetics?
• Which kinetic order is defined by a constant amount of drug being removed per unit of time?
• In a semi-log plot of concentration versus time for a drug with elimination, what does the slope primarily indicate?
• Define intrinsic clearance (CLint) and describe how it is measured in vitro.
• Which statement accurately describes ADME in pharmacokinetics?
• Which renal clearance processes are the main routes of urinary drug elimination?
• Is it true that some endogenous compounds can act as xenobiotics?
• In first-order kinetics, the magnitude of a drug's effect is best described as related to which statement?
• Which statement about regulatory bioequivalence criteria is accurate?
• On a concentration-effect curve, the plateau of the effect corresponds to the therapeutic effect.
• Which of the following sets lists formulation strategies used to improve solubility and dissolution rate of poorly soluble drugs?
• Which statement best describes IVIVC and its value in formulation development and regulatory submissions?
• True or False: A drug exhibiting a quantal response may be irreversible.
• The rate of drug elimination by the kidney at 1000x concentration is the same as at 1x concentration.
• Define hepatic extraction ratio (E) and explain its implications for flow-limited versus capacity-limited clearance.
• Time delays between pharmacokinetic changes and pharmacodynamic response can lead to ...
• When may response-time curves be more useful than concentration-time curves?
• Most kinetic processes in the body follow which order of kinetics?
• Which concentration-time profile describes an IV bolus administration?
• If the toxic dose to produce a response (TD50) is 25 mg and the dose for a desired effect (ED50) is 5 mg, the TI is 5.
• For a drug following first-order elimination, the shape of the concentration-time curve remains identical when dose is scaled by 1x, 10x, or 100x for the same route of administration.
• Which factor would you monitor to predict response for drugs with active metabolites?
• Which type of drugs are likely to have an instantaneous effect?
• TI reflects the safety margin between therapeutic and toxic doses.
• How does first-pass hepatic metabolism affect oral bioavailability, and which drugs show the greatest loss?
• Explain why plasma concentration of drugs with enantiomers does not correlate with response.
• IV Bolus vs Constant Infusion: Which statement describes IV bolus administration?
• Which pharmacokinetic metric is most directly related to overall drug exposure in the body?
• What does MEC stand for?
• What is the linear form of the first-order kinetics equation?
• Drug X is more active when given orally than when given IV. What can this indicate?
• Why is plasma concentration used to predict drug effect?
• Which statement best describes a quantal dose-response relationship?
• What PK considerations are relevant when dosing in obesity, and what modeling approach is commonly used to address them?
• The area under the concentration-time curve (AUC) represents what?
• Which sequence correctly describes the path of an orally administered drug from ingestion to excretion?
• For inhaled drugs, which statement best describes the determinants of systemic exposure?
• Xenobiotic is best defined as
• Which serves as the conduit delivering drug from the site of administration to tissues?
• In pharmacokinetics, two major concentration gradients are between which two sites?
• The negative slope of a concentration-time curve is also known as which of the following?
• For poorly soluble drugs taken orally, what step is typically rate-limiting for absorption?
• In a semi-log plot, if the line is steep, what does that indicate about elimination rate?
• Why are pediatric PK dosing regimens often based on weight or body surface area, and what PK principles underlie this practice?
• Why does warfarin take a couple of days to have its full effect?
• Which of the following is a case where plasma concentration does NOT correlate with pharmacologic response?
• In an IV bolus administration, how does plasma concentration change over time?
• Why does zero-order elimination lead to accumulation with increasing dose?
• Which antibiotic does not have concentration-dependent killing?
• Besides blood, which sample type is listed as a potential data source for concentration-time profiling?
• In the linear form of first-order kinetics, what is the slope of log C versus time?
• What effect does hepatic impairment typically have on hepatic clearance?
• If a drug is absorbed into the blood but is inactivated before reaching the site of action, which statement best describes this scenario?
• What is the primary PK objective of extended-release formulations?
• A large TI indicates higher safety.
• Which of the following is a pharmacokinetic mechanism contributing to tolerance?
• What does a larger area under the concentration-time curve (AUC) indicate about systemic exposure?
• How do PK and PD integrate in PK/PD models to inform dosing decisions?
• For IV administration, which relation describes how AUC depends on Dose and clearance?
• Which statement correctly describes Cmax?
• What does it mean by 'less negative elimination slope'?
• A larger TI implies a wider safety margin between therapeutic and toxic doses.
• The effect of a drug on target cells is known as
• During intermittent IV infusion, what determines the peak and trough concentrations, and how does this relate to clearance?
• What is enterohepatic recirculation, and what pharmacokinetic pattern might indicate its presence?
• Under what circumstances is a loading dose recommended, and what is its primary purpose?
• If a drug has a high hepatic extraction ratio, what is the likely effect on its oral bioavailability?
• Which term describes the tissue where a drug exerts its action?
• For concentration-dependent antibiotics, using larger, less frequent doses is often more effective.
• How would you modify dosing for a renally cleared drug in a patient with severe renal impairment?
• In a chiral drug with active S-enantiomer, why might total plasma concentration fail to predict effect?
• A positive slope on a concentration-time curve indicates what pharmacokinetic situation?
• Plasma concentration does not correlate with response in single-dose therapy.
• Which statement best explains why oral administration can be more pharmacologically active for certain prodrugs than IV administration?
• Which fate describes a free drug that becomes sequestered in other tissues with no immediate effect?
• Which statement best describes the concentration-time plot for zero-order elimination?
• The therapeutic index (TI) is defined as the ratio of the dose needed to produce a toxic effect to the dose needed to elicit the desired therapeutic response.
• In the well-stirred hepatic clearance model, CLint represents what?
• How is oral bioavailability defined, and how does it compare to intravenous exposure?
• In a quantal dose-response assessment, which of the following is a typical endpoint?
• A peak or horizontal line on the curve signifies what?
• Which statement about in vitro models used to predict in vivo absorption is most accurate?
• What pharmacokinetic pattern would most strongly suggest enterohepatic recirculation besides secondary peaks?
• ADME is best described as the study of pharmacokinetics.
• Which parameter remains constant across different doses in zero-order kinetics?
• What are the two main types of plasma concentration versus effect curves?
• Which factor would shift a concentration-time curve downward (lower plasma levels)?
• Why may there be a time delay even if the drug is fully absorbed?
• In predicting intestinal absorption, which statement is most accurate?
• Why is the unbound drug fraction the one that can be distributed and cleared?
• How is the volume of distribution defined, and what does an apparent Vd much larger than body water imply?
• Which statement correctly distinguishes absorption from distribution?
• In first-order kinetics, the half-life depends on the percentage of drug remaining.
• A concentration-time curve that starts at a high concentration and declines monotonically is most indicative of which route of administration?
• Which term describes a drug response that is all-or-none and typically plotted as the fraction of a population showing an effect?
• Which statement about graded responses is true?
• Which statement best describes quantal responses?
• The magnitude of a drug's response is proportional to its concentration at which site?
• Which statement best describes IVIVC in formulation development?
• What happens to the elimination rate in first-order kinetics as drug concentration falls?
• If the target for a drug is H. pylori in the stomach, which strategy would lead to higher success?
• Which statement best describes zero-order elimination?
• A plot of log concentration versus time that is linear indicates which type of kinetics?
• Which administration route provides an immediate peak concentration by bypassing absorption phase?
• In regulatory bioequivalence studies, which PK parameters are primarily compared between products, and what is the typical acceptance range?
• How does the elimination rate change as concentration increases for first-order and zero-order kinetics?
• Which formulation strategy is commonly used to improve solubility by converting a drug into an amorphous solid dispersion?
• The drug response is related to plasma concentration due to equilibrium. Which statement best describes this relationship?
• Which statement accurately describes MEC and MTC in relation to therapeutic and toxic effects?
• Decreased concentration of drug at the target site is an example of tolerance mechanism.
• Which PK metric corresponds to the peak drug concentration after an oral dose when comparing multiple candidates?
• Which scenario supports that a drug is a prodrug?
• True or False: A semi-log plot makes a zero-order kinetics equation appear as a straight line.
• Which statement about MEC and therapeutic response is true?
• In noncompartmental analysis (NCA) of PK data, which metrics are typically used to summarize oral drug disposition?
• Side effects arise because drugs distribute to non-target tissues during transit from administration to action.
• What in vitro tests can help predict in vivo intestinal absorption, and what is a common limitation of these tests?
• A reduction in blood pressure with antihypertensives is an example of which type of response?
• If dosing rate exceeds elimination capacity in zero-order kinetics, how does plasma concentration change over time?
• The magnitude of therapeutic response is proportional to concentration of drug at which site?
• __________ is the diminished response to same dosage of a drug, either developed slowly or acutely.
• For zero-order kinetics, which graph shows a straight line as drug concentration changes over time?
• Which PK parameter is commonly used to adjust dosing in hepatic impairment, and what does it reflect?
• What is total body clearance (CL) and how is it calculated after IV administration?
• How does urine pH influence ion trapping of weak acids and bases, and what is the clinical implication?
• Which statement best describes zero-order elimination?
• Pharmacokinetics describes
• Which statement best describes the relationship between dose and onset?
• Acquired resistance may be totally resistant in some bacteria or cancer cells.
• If a drug has a high hepatic extraction ratio, what primarily limits its clearance?
• How does drug partitioning into milk during lactation occur, and what PK considerations does it create for nursing infants?
• Which in vitro system is used to measure liver intrinsic clearance (CLint)?
• Which substances are absorbed in the stomach?
• Which statement best describes the duration of action?
• According to the vertical line test for a quantal-graded response curve, if the line does not bisect both the desired therapeutic effect and the adverse effects, the therapeutic index is larger.
• Drugs bound to plasma proteins mainly affect which pharmacokinetic parameter?
• Intensity of a drug's response is proportional to which variable?
• For methotrexate, response relates most closely to which factor?
• Regarding enantiomers, which statement is true?
• Which type of response is elicited only when drug concentration exceeds a critical threshold?
• What does the concentration-time graph look like for first-order versus zero-order elimination?
• Why are metabolized drugs bound to albumin not considered in the concentration-time curve?
• Under repeated dosing, which kinetic profile is most likely to lead to drug accumulation and toxicity?
• For the concentration-effect curve, increasing dose from 1x to 10x to 100x does not change the curve shape for the same route.
• In general, what determines the magnitude of the effect of a drug?
• Why do many drugs have side effects?
• What is downregulation?
• Pharmacokinetic adaptations can alter absorption when food or drug interactions are present.
• What is the primary determinant of the apparent volume of distribution for a drug that partitions strongly into tissues?
• Which two properties does the Biopharmaceutics Classification System (BCS) classify drugs by, and how do they influence oral absorption?
• Compared with oral administration, an intramuscular injection would shift the concentration-time curve in which direction?
• What does a quantal dose-response curve measure?
• Which response is known as an all-or-none response?
• Which modeling approaches are commonly used to adjust pediatric dosing for growth and maturation?
• Describe the well-stirred hepatic clearance model and identify its key variables.
• After the stomach, absorption of most drugs continues primarily in which site?
• Which type of kinetics is more likely to result in drug toxicity under repeated dosing?
• Gentamicin's efficacy increases with higher peak concentrations; the statement is true.
• How does an intravenous infusion alter the concentration-time profile compared with a bolus dose?
• Which type of response is proportional to concentration and usually reversible?
• Peak time (Tmax) is defined as which of the following?
• In first-order kinetics, if 20 percent of the drug is removed every hour, how does the amount removed per hour relate to concentration?
• Onset of action is defined as the time to reach MEC.
• If a semi-log plot shows a negative slope and the slope is steeper than another, what does this indicate?
• Which statement best defines the duration of action for a drug on a concentration-time graph?
• What is nonlinear mixed-effects modeling (nlME) in population PK, and what is its major advantage?
• If a drug does not have concentration-dependent killing, how will the dose-response curve look and what type of kinetics characterize it?
• True or false: It is impossible to determine the total amount of drug present in the body by direct methods.
• Doubling to 100x the dose would result in a longer half-life.
• Allometric scaling in pharmacokinetics commonly uses which body size descriptor?
• How does the half-life change in first-order versus zero-order kinetics?
• Which statement describes the relationship between plasma concentration changes and tissue distribution?
• In a linear plot of first-order kinetics (log C vs time), what does the y-intercept represent?
• A peak in a concentration-time curve reflects what about the rates of absorption and elimination?
• What regulatory bioequivalence acceptance criterion for AUC and Cmax is commonly used, and what is the rationale behind it?
• Which matrix is commonly used to collect data for a concentration-time curve?
• In a concentration-time curve, what does the x-axis represent?
• Which is NOT listed as a route of drug elimination?
• What factors largely determine systemic exposure for inhaled drugs intended for lung therapy?
• What does MTC stand for?
• What does the area under the concentration-time curve (AUC) represent in pharmacokinetics, and how is it related to clearance after intravenous administration?
• Differentiate between one-compartment and two-compartment models in terms of their distribution phases.
• Fluctuating antibiotic concentrations are sometimes more desirable than steady concentrations.
• How many half-lives are typically needed to reach steady-state concentrations for most drugs?
• Which statement about zero-order elimination is true?
• Tolerance vs acquired resistance
• How can patient covariates such as weight and renal function contribute to interindividual PK variability?
• On a concentration-time graph, onset of action is best defined as the time to reach MEC.
• How does the route of administration influence Tmax and overall absorption rate?
• Which statement best describes zero-order kinetics?
• How is bioequivalence typically assessed in regulatory studies, and what does the 80–125% acceptance window represent?
• Which plot yields a straight line for first-order elimination?
• In noncompartmental analysis, which metric is used to characterize the extent of drug exposure from time zero to infinity?
• Which organ is the primary site of metabolism via portal circulation after oral administration?
• True or false: When blood is collected, drug molecules are in the water portion of blood.
• Which statement is true for zero-order elimination?
• Which statement best describes the relationship between serum and plasma as described in the material?
• On a concentration-time curve, which metric represents the total amount of drug absorbed systemically?
• In first-order kinetics, how does the half-life respond to changes in dose?
• Which sample is not listed as a data source for concentration-time profiling in the material?