Distribution Flashcards
(15 cards)
Distribution is affected by three main factors. These are?
Volume of distribution
Protein binding e.g. to Albumin
Restrictions e.g. Placenta or blood-brain-barrier
What is the equation for volume of distribution
Dose/ concentration
What does the volume of distribution tell us about a drug?
Where it goes in the body
Where is drug concentration commonly measured from?
Blood (plasma)
When might a loading dose be needed?
To reach an adequate plasma concentration when there is a large volume of distribution.
What is the main role of Albumin
To maintain osmotic pressure
Where is albumin produced?
Liver
When a drug binds to a protein, what happens to diffusion
It is unable to diffuse due to its large size
Why might liver failure result in a higher plasma concentration of drug?
Because there is less albumin to bind to drugs, therefore, more free drug in the plasma
When is alpha 1 acid glycoprotein released
During physiological stress e.g. infection, burns, illness or injury
A drug that is highly protein-bound will have what effect on volume distribution?
Lower the volume distribution
A drug that is not highly protein bound will have what effect on volume distribution?
High volume distribution
Name two barriers to drug distribution.
High mollecular weight
Hydrophillic
What must a drug be to pass through the blood-brain barrier?
Highly lipid soluable
What happends to the effectiveness of the blood brain barrier with age?
It decreases
