pharmakinetic concepts

Question 1

absorption

Answer 1

what happens to a drug from the time it is introduce to the body until it reaches the bloodstream to be circulated
can be affected by form of dosage, route of administration, GI function, first pass effect

Question 2

distribution

Answer 2

involves the moment of a drug into the body tissues
largely dependent on the adequacy of blood circulation
protein binding - drug molecules that are bound to plasma proteins are pharmacologically inactive
blood brain barrier - composed of capillaries that have walls limiting movement of drug molecules into the brain tissue selectively permeable water soluble don’t cross lipid soluble do cross

Question 3

metabolism

Answer 3

method by which drugs are inactivated to in the body
first pass affect - drugs given orally are absorbed from GI tract and carried directly to the liver where some are extensively metabolized causing only part of the dose to reach systemic circulation
outcomes of metabolism - Increased renal excretion
 Inactivation
 Increased therapeutic effect
 Activation of pro drugs into active forms
 Decrease toxicity when active forms become inactive
 Increased toxicity when inactive forms become inactive

Question 4

excretion

Answer 4

elimination of the drug from the body
need adequate functioning of circulatory system
adequate functioning of excretion organs, kidneys, bowels, lungs, integument