PHARM - Pharmacokinetics - Drug Absorption and Distribution - Week 1 Flashcards
Define pharmacokinetics.
The process of getting drugs to and from their sites of action.
What are 4 key questions that are asked for clinical drug use?
What form is the drug in?
Where do you put it?
How much do you use?
How often do you use it?
Define administration.
Giving the drug to a recipient.
Define absoprtion.
The drug entering circulation.
Define distribution.
The drug spreading throughout the body.
Define elimination.
The removal of the drug from the body.
Name 4 factors that can influence the choice of route of administration.
Patient convenience - oral/rectal/injection
Cost
Bioavailability
Local vs systemic effect
Define local and systemic administration (4).
Local -drug exerts effect at or near administration site -access to limited tissue Systemic -drug enters the bloodstream -will access many tissue
What limits drug access to tissue with local administration?
Absorption
What determines drug access to tissue with systemic administration?
Distribution
How can the side effects of a locally administered drug be reduced?
By choosing a concentration so that if a drug is absorbed, it is too low to cause systemic effects.
What kind of administration route does not require the drug to be absorbed?
Intravenous injection only. All others require absorption.
What is drug distribution driven by?
Circulation
Is drug distribution uniform?
No, its rarely uniform.
How does drug molecular size affect drug distribution?
Smaller molecules cross the vascular endothelium easier
