Pharmacokinetics

Question 1

are xenobiotics

Answer 1

Drugs

Question 2

chemical which is found in an organism but which is not normally produced or expected to be present in it) (Biocompatible)

Answer 2

xenobiotic

Question 3

Disciplines Involved in Drug Development

Answer 3

Physiology and Pharmacology required to select appropriate drug candidates.

Physics and Physical Chemistry and Mathematics involved in dosage form design.

Kintics, Analytical Chemistry and Therapeutics required to determine appropriate dose.

Question 4

the study of the kinetics of drug absorption, distribution, metabolism and excretion of drugs (ADME) (body action)

Answer 4

Pharmacokinetics

Question 5

the study of factors that affect the bioavailability of drugs in animals and man.

Answer 5

Biopharmaceutics

Question 6

the study of the biochemical and physiological effects of drugs on the body or on microorganisms or parasites within or on the body and the mechanisms of drug action and the relationship between drug concentration and effect.

Answer 6

Pharmacodynamics

Question 7

ADME

Answer 7

Pharmacokinetics

Question 8

Transfer of drug from the absorptions site (stomach, intestine) to the blood. Rapid and not reversible.

Answer 8

Absorption

Question 9

Fate of drug after Absorption (Distribution and Elimination).

Answer 9

Disposition

Question 10

Transfer of drug from the blood to extravascular fluid, tissue, plasma proteins or other fluids. Rapid and reversible. Usually occurs much more rapidly than elimination.

Answer 10

Distribution

Question 11

Rate of distribution to tissue/organ is determined by

Answer 11

blood flow

Question 12

Biotransformation of drug, mainly in liver (Also kidney, skin).

Answer 12

Metabolism

Question 13

Removal of drug compound and metabolites from the body.

Answer 13

Elimination

Question 14

Goals of Pharmacokinetics

Answer 14

A. To compare the pharmacology and toxicology of drugs and their relationship to Cp of both the drug and its metabolite/s.

B. To determine the accumulation characteristics of drugs for the evaluation of chronic toxicity.

C. To individualize and optimize the therapeutic management of individual patients (dose, time).

D. To determine patient compliance

E. To evaluate the effect of disease states on drug elimination.

Question 15

used an alternative to treadmill stress and used for elderly patients.

Answer 15

Dipyridamole (Persantine)

Question 16

can increase the blood flow up to four to five times than in normal value.

Answer 16

Adenosine (Adenocard)

Question 17

Used for increase of cerebral blood flow in cerebral perfusion imaging

Answer 17

Acetazolamide (diamox)

Question 18

quantity that is always unchanged

Answer 18

Constant

Question 19

mathematical constants

Answer 19

. π and e

Question 20

physical constants

Answer 20

R, k (Boltzmmann constant) and N (Avagadro’s number)

Question 21

constant that is not universal but does not vary in a particular instance.

Answer 21

Parameter

Question 22

Examples of parameters

Answer 22

Rate constants, equilibrium constants, slopes and intercepts of graphs

Question 23

a quantity that is changing during the course of an experiment

Answer 23

Variable

Question 24

Examples of variables

Answer 24

axes of a graph - In a rate process time and concentration are variable.

Question 25

the half-life of a drug is 2 hrs, and the concentration at 30 minutes were found 20 mg/mL - What is the half-life

Answer 25

half-life, t1/2 = 0.693/k

Question 26

Decay Function

Answer 26

f(t)=e^-kt=exp(-kt)

Question 27

Growth Function

Answer 27

f(t)=1-e^-kt

Question 28

Intravascular routes

Answer 28

Intravenous | Intra-arterial

Question 29

Extravascular routes

Answer 29

``` Oral Buccal Rectal Pilmonary Intramuscular and subcuteaneous injection Etc. ```

Question 30

Intravascular Administration (bolus) characteristics

Answer 30

No absorption phase Immediate onset of action Entire dose is available Route used frequently in life threatening situations Adverse reactions difficult to reverse. Accurate dosing is thus essential.

Question 31

Which function would be used for a bolus

Answer 31

Decay Function

Question 32

An absorption phase is present. Onset of action determined by a number of factors including formulation, route of administration (Oral, pulmonary, etc.), drug physicochemical properties, and physiological properties. The entire administered dose may not be available.

Answer 32

Extravascular Administration

Question 33

Which function would be used for extravascular administration

Answer 33

Combined Decay and Growth Function

Question 34

Which function would be used for intravascular infusion

Answer 34

Growth Function

Question 35

represent the area under the curve (AUC)

Answer 35

Definite integrals

Question 36

In pharmacokinetics the integral is often referred to as

Answer 36

AUC

Question 37

How to get AUC

Answer 37

Integration or Trapezoid Rule

Question 38

Trapezoid Rule Equation

Answer 38

(b-a) ( h(a) – h(b)) Area= --------------------------- 2

Question 39

a technique for approximating the definite integral

Answer 39

Trapezoid Rule

Question 40

How does the Trapezoid Rule work

Answer 40

The trapezoidal rule works by approximating the region under the graph of the function f(x) as a trapezoid and calculating its area

Question 41

assumes quadratic dependence in this small interval - more accurate than trapazoid rule.

Answer 41

Simpson’s Rule

Question 42

assumes function is linear in the small interval h

Answer 42

Trapezoid rule

Question 43

AUC provides

Answer 43

the pk information such a duration of drug in blood, tmax, cmax, bioavailability etc.

Question 44

Rate Equation

Answer 44

Rate depends on concentration

Question 45

Decomposition reactions in the solid phase often show

Answer 45

zero order kinetics - not dependent on concentration

Question 46

characterized by exponential decay

Answer 46

First order reactions

Question 47

time required for concentration to become half

Answer 47

Half-Life

Question 48

half life is 2 hr, how much will be left after 4 hrs?

Answer 48

25%

Question 49

Is Half-life of first order reactions constant or variable

Answer 49

constant

Question 50

How do Drug diffuse from compartments

Answer 50

Drug diffuses from compartments with high concentration to those with low concentration.

Question 51

Pharmacokinetic models recognize that _____is an important mechanism for the absorption, distribution and excretion of drugs and their metabolites.

Answer 51

passive diffusion

Question 52

What is the central compartment

Answer 52

blood and organs which are perfuse such as heart, kidney have same blood flow as in the blood vessel

Question 53

considered as peripheral compartment.

Answer 53

Tight tissues such as muscle, bone where blood flow is more slower