2. Distribution
Today we are only focusing on distribution
of drugs and why a nurse should know this
The analogy of highways will be used to
help explain difficult ideas
Site of Action
3. Distribution
Distribution is the
movement of drugs
throughout the human
body
The way drugs travel is
through the blood of
the vascular system
6. Exiting the Vascular System
Once drugs have
left the vascular
system, they must
pass between
capillary cells
7. Site of Action
Some drugs must
enter the cell to
reach the site of
action
Other drugs
interact with
receptors on the
outside of the cell
8. Stop and Think!
Understanding distribution is
an important factor to
nursing, you must be able to
determine if a drug can
reach it’s target
What about the young,
elderly and pregnant?
9. Blood-Brain Barrier
A blood-brain barrier (BBB) refers to the structure of
capillaries in the central nervous system
The BBB is a major site of blood to central nervous
system exchange
Tight junctions, between cells that make up the
walls of most capillaries, keep drugs from passing
through
Drugs must be lipid-soluble or have a transporter to
cross the BBB
Some drugs dissolve directly into the membrane
10. Some drugs are not able to
enter through the blood-brain
barrier!
11. Placental Drug Transfer
Membranes of the
placenta keep circulation
of mother and fetus
separate, however it is not
an absolute barrier
Drugs that pass the
placenta can cause
significant birth defects
12. Protein Binding
Drugs most often form
reversible bonds with
proteins in the body
Protein Albumin is the most
common, it makes up 50-
75% of blood proteins
Because Albumin cannot
leave the bloodstream, it
restricts bound drugs from
reaching their sites of
14. Sources
Abbot, N. J. (2009). Structure and Function
of the Blood-Brain Barrier. Medline.
<http://ncbi.nlm.nih.gov/pubmed/19664713.
ESRD Network of New England.
<networkofnewengland.org/albfac.pdf.
Lehne, R. A. (2013). Pharmacology for
Nursing Care 8th ed. St. Louis, MO: Elsevier Inc.
Pharmacokinetics: Distribution. <http://psych.
fullerton.edu/mwhite/475pdf475
Pharmacokinetics-Distribution.pdf.
