2 drug movement caldwell

Question 1

Describe minimal effective dose (MEC).

Answer 1

concentration of drug in plasma at which desired effects will begin to occur by definition it is lowest point of the therapeutic range

Question 2

Draw a diagram of drug concentration versus time including MEC.

Answer 2

Question 3

Apply four ways molecules can pass through membranes to a clinically-relevant scenario.

Answer 3

aqueous diffusion - endothel junctions and pores, conc. dependent lipid diffusion - diffusion through a membrane, highly partition coefficient dependent transporters - proteins that physically moves a molecule from one side of the membrane to the other, limited by transport maximum, may require energy endo/exocytosis - vacuolization allowing extremely bulky and polar molecules to be transported ie. steroids, iron, vitamin B12

Question 4

Contrast diffusion by aqueous pores versus transporters

Answer 4

aqueous pores- constitutively open, non inhibitable, not ligand specific, no transport maximum transporters - inhibitable, limited by transport maximum, very ligand specific

Question 5

Diagram endocytosis and exocytosis of transport molecules across a cell layer.

Answer 5

Question 6

Write Fick’s Law of Diffusion.

Answer 6

Rate of Diffusion = (Surface Area x [Substance] ) / (Membrane Resistance x Thickness of Membrane)