Exam 1 - Drug Distribution

Question 1

plasma

Answer 1

yellowish, liquid component of blood that carries cells, nutrients, hormones, and waste products, making up about 55% of total blood volume

Question 2

What are factors affecting drug distribution?

Answer 2

• blood flow
• ease of drug crossing membrane barriers
• hydrophilicity/hydrophobicity of drug
• binding to plasma proteins

Question 3

How does blood flow affect drug distribution?

Answer 3

drugs go into tissues in varying amounts

Question 4

What is the main plasma binding protein?

Answer 4

albumin

Question 5

What does binding to plasma proteins do to drugs?

Answer 5

makes them incapable of moving into tissues

Question 6

Blood-brain barrier

Answer 6

semi-permeable barrier between blood and brain
* composed of tight junctions between blood cessel wall cells within brain capillaries
* cell membranes from selective barrier that is much more permeable to lipid-soluble drugs

Question 7

What is the consequence of the blood-brain barrier?

Answer 7

lack of aqueous channels between cells
* means drugs must transit cells membranes and enter brain via passive diffusion or transporters (which are selective and limited)