25. Pharmakinetics: Basic Principles and Drug Absorption

Question 1

What is pharmacodynamics?

Answer 1

Actions of a drug on the body

Question 2

What are pharmacokinetics?

Answer 2

Effect of the body on the drug

Question 3

What are the 4 parts of pharmacokinetics?

Answer 3

Absorption
Distribution
Metabolism
Excretion

Question 4

How can a drug pass across membranes?

Answer 4

Pores/ion channels
Passive diffusion
Carrier mediated
Pinocytosis

Question 5

What are the 3 main routes of administration?

Answer 5

Topical
Enteral
Parental

Question 6

What are the challenges to overcome with oral medication?

Answer 6

Highly polarised drugs are poorly absorbed
Peptide chains are broken down
Has to disintegrate
Must account for gastric emptying
First pass metabolism

Question 7

What is first pass metabolism?

Answer 7

Drug goes directly from GI tract to the portal vein and onto the liver
Broken down before it can enter circulation

Question 8

What is the area under the curve?

Answer 8

Measure of total amount of drug that enters the body after administration
Calculated from a plasma concentration/time graph

Question 9

What is bioavailability?

Answer 9

Fraction of administrated dose that reaches the systemic circulation as intact drug
Compare plasma levels after preferred administration to after IV