Apex Kinetics/dynamics

Question 1

Volume of Distribution

Answer 1

The relationship between a drugs plasma concentration following a specific dose

Question 2

Theoretically - what does the volume of distribution measure?

Answer 2

How a drug distributes throughout the body

Question 3

Volume of distribution =

Answer 3

Amount of drug/desired plasma concentration

Question 4

Characteristics of drug with a large Vd

Answer 4

Lipophilic - distributes into TBW and fat
Requires a high dose
Exceeds TBW

Question 5

Characteristics of drug with low Vd

Answer 5

Less than TBW
Hydrophilic
Does not distribute into fat
Requires lower dose

Question 6

Volume of distribution is effected by?

Answer 6

Drug characteristics: molecular size, ionization, protein binding
Patient characteristics: pregnancy, burns

Question 7

Bioavailability of IV drugs

Answer 7

1 (or 100%)

Question 8

Clearance is directly proportional to: (pick 2)
Extraction ratio
Half life
Concentration in central compartment
Blood flow to clearing organ

Answer 8

Blood flow to clearing organ

Extraction ratio

Question 9

In which of the following instances is a drug more likely to pass through the lipid membrane?
A weak acid where the pH of the solution is < the pKa of the drug
A weak acid where the ph of the solution is > the pKa of the drug

Answer 9

A weak acid where the pH of the solution is < the pKa of the drug

Question 10

In which of the following instances is a drug more likely to pass through the lipid membrane?
A weak base where the pH of the solution is < the pKa of the drug
A weak base where the ph of the solution is > the pKa of the drug

Answer 10

A weak base where the ph of the solution is > the pKa of the drug