Distribution

Question 1

What is drug distribution?

Answer 1

Following absorption into the bloodstream, a drug distributes into interstitial and intracellular fluids. This process reflects a number of physiological factors and the particular properties of the individual drug.

Question 2

What are the 3 main body water compartments through which a drug is distributed?

Answer 2

• Vascular
• extracellular
• intracellular

Question 3

What does Body water compartments mean

Answer 3

The higher the apparent volume of distribution of a drug, the more extensively it is distributed to the body tissues.

Question 4

What is the volume of distribution?

Answer 4

Volume of fluid required to contain the total amount of drug in the body at the same concentration as that present in the plasma.

VoD = Dose / Concentration in plasma

Question 5

What is the volume of distribution and the loading dose?

Answer 5

Loading dose (mg) = Target concentration (mg/L) x Volume of distribution (L)

Question 6

List the factors that affect drug distribution

Answer 6

• plasma protein binding
• accumulation in fat
• tissue binding
• blood brain barriers
• placental barrier
• vascularity / blood flow