III - Pharmacokinetics

Question 1

Concentration of a drug at the receptor site

Answer 1

Effective Drug Concentrationh

Question 2

The concentration at the receptor site is usually proportional to the drug’s concentration in the plasma or whole blood at equilibrium except for

Answer 2

topical drugs

Question 3

Volume at which the drug would need to be uniformly distributed to produce an observed blood concentration

Answer 3

Apparent Volume of Distribution

Question 4

Apparent Volume of Distribution =

Answer 4

Vd = amount of drug in the body/plasma drug concentration

Question 5

Apparent Volume of Distribution can be altered by

Answer 5

liver or kidney disease

Question 6

Distribution: Low Vd

Answer 6

blood

Question 7

Distribution: Medium Vd

Answer 7

extracellular space, body water

Question 8

Distribution: High Vd

Answer 8

tissues

Question 9

Relates the rate of elimination of the plasma concentration

Answer 9

Clearance

Question 10

Clearance =

Answer 10

Cl = rate of elimination/plasma drug concentration

Question 11

Clearance depends on

Answer 11

drug, condition of organs of elimination

Question 12

Clearance is a constant proportion

Answer 12

First-Order Kinetics

Question 13

Clearance is a constant amount

Answer 13

Zero-Order Kinetics

Question 14

Most important pharmacokinetic parameter to be considered in defining a rational steady state during dosage regimen

Answer 14

Clearance

Question 15

Condition in which the average total amount of drug in the body does not change over multiple dosing intervals

Answer 15

Steady State

Question 16

Rate of drug input equals the rate of elimination

Answer 16

Steady State

Question 17

Steady State is reached after _____ half-lives of the drug.

Answer 17

4-5

Question 18

Constant for drugs following first order kinetics

Answer 18

Half-Life

Question 19

Half-Life =

Answer 19

t1/2 = (0.693 x volume of distrubution)/clearance

Question 20

Fraction of the administered dose that reaches the systemic circulation

Answer 20

Bioavailability

Question 21

Drugs administered via _____ have 100% bioavailability.

Answer 21

IV

Question 22

Bioavailability is reduced by

Answer 22

incomplete absorption, first-pass metabolism, pre-systemic redistribution

Question 23

Bioavailability is determined by

Answer 23

computing the area under the plasma concentration curve (AUC)

Question 24

Plan for a drug administration over a time period

Answer 24

Dosage Regimen

Question 25

Dosage Regimen results in the achievement of _____ levels of the drug without exceeding _____.

Answer 25

therapeutic levels, minimum toxic concentration

Question 26

Equal to the rate of elimination at steady state

Answer 26

Maintenance Dose

Question 27

Maintenance Dose =

Answer 27

(clearance x desired plasma concentration)/bioavailability

Question 28

Important to maintain concentration above minimum therapeutic level

Answer 28

Maintenance Dose

Question 29

Not involved in calculating maintenance dose

Answer 29

Volume of Distribtion

Question 30

If the therapeutic concentration must be achieved rapidly and the volume of distribution is large

Answer 30

Loading Dose

Question 31

Not involved in calculating loading dose

Answer 31

Clearance

Question 32

Safe range between the minimum therapeutic concentration and the minimum toxic concentration of a drug

Answer 32

Therapeutic Window

Question 33

Adjustment of Dosage in Renal Impairment

Answer 33

Average Dose x Crea Clearance / 100mL/min

Question 34

Used to calculate the patient’s creatinine clearance

Answer 34

Cockroft-Gault Equation

Question 35

Cockroft-Gault Equation

Answer 35

[(140-age) x weight (kg)] / [72xcrea mg/dl] (x 0.85 in females)