Pharmacokinetics

Question 1

What is meant by pharmacokinetics

Answer 1

What the body does to the drug

Question 2

What are the two types of clearance of drugs in the body

Answer 2

Zero order kinetics

First order kinetics

Question 3

What is zero order kinetics

Answer 3

The drug is cleared at the same rate regardless of the concentration

Question 4

What is the equation for a zero order kinetic

Answer 4

The change in concentration divided by the change in time which equals negative K

Question 5

What is meant by first order kinetics

Answer 5

The rate of clearance depends on The amount of drug in the body

Question 6

What is the equation for FIrst order kinetic drug

Answer 6

Change in concentration divided by change in time equals negative KA

Question 7

What can zero order kinetics lead to

Answer 7

Accumulation of drug in body which can lead to overdose

Question 8

What is a one compartment model

Answer 8

Means that drug is absorbed in the plasma and is then eliminated

Question 9

What is a two compartment model

Answer 9

Drug is absorbed into plasma and is then distributed into a second compartment and then will be eliminated from both compartments

Question 10

What is half life

Answer 10

 The time taken for the plasma concentration of a drug to decline by 50%

Question 11

How can you calculate the elimination rate constant(k) 

Answer 11

convert plasma drag concentrations to natural log and plot against Time
K is then equal to the gradient of this slope

Question 12

What equation links half life and elimination constant

Answer 12

T1/2 = 0.693/k

Question 13

What is absorption

Answer 13

The process by which a job moves from the site of administration to the sites of action

Question 14

What unique properties does oral absorption require

Answer 14

Drug needs to be water soluble in the gut
Lipophilic for membrane permeation
Water soluble in plasma

Question 15

What is distribution

Answer 15

The process by which a drug moves from the bloodstream into the peripheral tissues

Question 16

What is distribution driven bye

Answer 16

The relative affinity of binding for blood and tissue compartments

Question 17

How can you quantify distribution

Answer 17

The volume of distribution

Question 18

What is the volume of distribution (Vd) 

Answer 18

The total amount of drug dose divided by plasma concentration at t0

Question 19

What is metabolism

Answer 19

The irreversible chemical alteration of a drug by biological system

Question 20

What is a phase 1 metabolic reaction

Answer 20

A new chemical group is introduced e.g by :
Oxidative reactions
Reduction reactions
Hydrolysis reactions

Question 21

What is a phase 2 metabolic reaction

Answer 21

Conjugation reactions. Conjugates molecule with a charged chemical species via :

• glucournidation
• acylation
• sulfation

Question 22

What is meant by excretion

Answer 22

Clearance is the efficiency of irreversible elimination of a drug from the systemic circulation
Volume of blood cleared of drug per unit time

Question 23

What are some important considerations with clearance

Answer 23

Can be limited by organ bloodflow
Can include saturable processes
Increase both metabolism and excretion
Clearance is additive

Question 24

What is bioavailability

Answer 24

The fraction of an change drug that reaches the systemic circulation

Question 25

What is the bioavailability in IV dosing

Answer 25

100% so always equals one

Question 26

What does bioavailability depend on in oral dosing

Answer 26

Absorption from the guy

Can be limited by Gut/hepatic metabolism/excretion