Pharmacokinetics

Question 1

A dosage regimen includes:

Answer 1

dosage
route of admin
frequency
duration of admin

Question 2

The optimum dosage regimen is described as?

Answer 2

effective
nontoxic
w/o prolonged drug residues in tissues of food animals

Question 3

pharmacokinetic definition

Answer 3

the mathematical description of the plasma concentration-time course

Question 4

the mathematical description of the plasma concentration-time course

Answer 4

pharmacokinetics

Question 5

is the time to peak plasma concentration (Tmax)

Answer 5

rate of absorption

Question 6

rate of absorption is..

Answer 6

the time to peak plasma concentration (Tmax)

Question 7

the extent of absorption is measured by

Answer 7

systemic bioavailability (F%)

Question 8

When you measure systemic bioavailability you are determining the…

Answer 8

extent of absorption

Question 9

what is the fraction of the dose which reaches the systemic circulation intact

Answer 9

systemic bioavailability

Question 10

systemic bioavailability (F%) =

Answer 10

AUC extravasc x 100 / AUC IV

Question 11

AUC stands for

Answer 11

area under the plasma concentration-time curve

Question 12

compartments refers to

Answer 12

those tissues and organs for which the rates of uptake and subsequent clearance of a drug are similar

Question 13

one-compartment model

Answer 13

all tissues and organs which the drug penetrates behave as if they were in ready equilibrium with the blood

Question 14

rate of distribution

Answer 14

estimated by the distribution phase half-time (t1/2a) in the two compartment model

Question 15

extent of distribution

Answer 15

measured by the apparent volume of distribution Vd

Question 16

can be defined as the volume of fluid which would be required to contain the amount of the drug in the body if it were uniformly distributed, and the concentration in that fluid was equal to the concentration in the plasma

Answer 16

apparent volume of distribution (Vd)

Question 17

Vd(L/kg)=

Answer 17

amount of drug in body (D) / plasma drug concentration (Cp)

Question 18

the amount of drug in the body =

Answer 18

the dose IV

Question 19

for IV the Vd(L/kg) =

Answer 19

Dose (D) (mg/kg) / Cp (mg/L)

Question 20

for extravascular the Vd (L/kg) =

Answer 20

D (mg/kg) X F% / Cp (mg/L)

Question 21

When Vd < 1L/kg -

Answer 21

the drug has a limited distribution (tends to stay in plasma)

Question 22

When Vd = 1L/kg -

Answer 22

the drug has a wide distribution

Question 23

When Vd > 1L/kg -

Answer 23

the drug has a very wide distribution

Question 24

elimination is measured by

Answer 24

half life or total body clearance

Question 25

half life is the time required for

Answer 25

the body to eliminate 1/2 of the drug it contains

Question 26

elimination of most drugs follows ____

Answer 26

first order kinetics

Question 27

first order kinetics means

Answer 27

the rate of removal of drug from the plasma is proportional to the concentration present at a given time (a constant percent of drug is eliminated per unit time)

Question 28

which drug in cats follows zero order kinetics

Answer 28

aspirin

Question 29

which drug in dogs and horses follows zero order kinetics

Answer 29

phenylbutazone

Question 30

If your drug concentration in plasma is 10mg/ml then what is the first half life concentration

Answer 30

5mg/ml

Question 31

the half life determines...

Answer 31

the rate at which plasma concentration of a drug rises during constant IV infusion to attain a steady-state concentration

Question 32

is the plasma concentration of drug when the maintenance rate of drug administration is equal to the rate of elimination

Answer 32

steady-state plasma concentration or plateau (Cp(ss))

Question 33

how many half lives till plasma conc. reaches 93.75%

Answer 33

4 half lives

Question 34

about what percent of the steady state concentration is achieved in 3.3 half lives

Answer 34

90%

Question 35

a faster rate of infusion does not change the time needed to achieve steady state; what does change

Answer 35

the steady state concentration Css, changes

Question 36

the rate of drug elimination from the body, by all routes, relative to the concentration of drug in plasma

Answer 36

total body clearance

Question 37

CLB=

Answer 37

CLr+ CLnr

Question 38

the volume of plasma cleared of the drug per unit time (mL/min)

Answer 38

plasma clearance (CLp)

Question 39

plasma clearance (CLp)=

Answer 39

rate of elimination (mg/min) / plasma drug concentration (mg/mL)

Question 40

the rate of elimination (mg/min)=

Answer 40

urine flow (mL/min) X concentration of drug in urine (mg/mL)

Question 41

clearance is related to the

Answer 41

Vd T1/2 elimination rate constant (k)

Question 42

CLB=

Answer 42

Vd X 0.693 / t1/2

Question 43

the fraction of the drug removed from the perfusing blood by an organ

Answer 43

extraction ratio

Question 44

extraction ratio (E) =

Answer 44

(CA_)- CV/ CA

Question 45

CA is

Answer 45

the concentration of drugs in arterial blood entering the organ

Question 46

CV is

Answer 46

the concentration of drug in venous blood leaving the organ

Question 47

Cl organ =

Answer 47

Q x E

Question 48

Q is

Answer 48

blood flow to the organ

Question 49

E is

Answer 49

extraction ratio

Question 50

list 4 examples of drugs that have high hepatic extraction ratio

Answer 50

lidocaine propranolol diazepam nitroglycerin

Question 51

dosing rate =

Answer 51

clearance X desired steady state

Question 52

the daily dose =

Answer 52

dose/min X 60 min per hour X 24 hours

Question 53

loading dose=

Answer 53

Vd X desired serum drug concentration

Question 54

adjusted dose for renal disease =

Answer 54

normal dose X (patients renal clearance / normal renal clearance)

Question 55

adjusted dose interval for renal disease=

Answer 55

normal dose interval X (normal renal clearance/ patients renal clearance)

Question 56

renal clearance is usually estimated by

Answer 56

creatinine clearance

Question 57

``` which of the following is NOT an age-related factor to consider when dosing a neonate? A. increased plasma protein binding B. increased total body water C. decreased drug metabolism D. decreased blood brain barrier ```

Answer 57

Increased plasma protein binding

Question 58

``` ruminants have a tolerance to barbiturates is an example of ____ A. cross tolerance B. tachyphylaxis C. natural tolerance D. acquired tolerance E. down regulation of receptors ```

Answer 58

natural tolerance

Question 59

what two diseases can decrease renal excretion

Answer 59

Kidney disease and congestive heart failure

Question 60

which is an example of an undesirable drug interaction? A. amino glycoside antibiotic + amino glycoside antibiotic B. chloramphenicol + phenobarbital C. aminoglycoside AB + muscle relaxant D. A & C E. all of the above

Answer 60

all above

Question 61

potentiation is a drug to drug interaction where there is ____ of drug effects

Answer 61

intensification

Question 62

alteration of distribution is the pharmacokinetic interaction in which...

Answer 62

strongly bound drugs to plasma proteins displace weakly bound drugs increasing their effects

Question 63

``` which is not a dosing factor to the environment? A. humidity B. atmospheric pressure C. ambient temp D. oxygen ```

Answer 63

atmospheric pressure

Question 64

drug reactions that are genetically determined, abnormal, unpredictable and caused by reactive drug metabolites are called...

Answer 64

idiosyncratic drug reactions

Question 65

a vet must consider which of the following factors before dosing a geriatric animal?

Answer 65

reduction in plasma albumin

Question 66

morphine effects vary by species: T/F?

Answer 66

true

Question 67

boxers are sensitive to which drug?

Answer 67

phenothiazine

Question 68

chronic phenobarbital therapy can cause hyperactivity in children: T/F?

Answer 68

false

Question 69

route of admin can modify what?

Answer 69

onset of action | duration of action