Distribution

DistributionTeam HabermanGreg DaneAmanda Haberman Whitney Joseph/Woods Lauren Hinchey

DistributionToday we are only focusing on distribution of drugs and why a nurse should know thisThe analogy of highways will be used to help explain difficult ideas

Site of Action

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DistributionDistribution is the movement of drugs throughout the human bodyThe way drugs travel is through the blood of the vascular system

The Vascular System

Blood Flow to Tissues

VS.

Exiting the Vascular SystemOnce drugs have left the vascular system, they must pass between capillary cells

Site of ActionSome drugs must enter the cell to reach the site of actionOther drugs interact with receptors on the outside of the cell

Stop and Think!Understanding distribution is an important factor to nursing, you must be able to determine if a drug can reach its targetWhat about the young, elderly and pregnant?

Blood-Brain BarrierA blood-brain barrier (BBB) refers to the structure of capillaries in the central nervous systemThe 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 throughDrugs must be lipid-soluble or have a transporter to cross the BBB Some drugs dissolve directly into the membrane

Some drugs are not able to enter through the blood-brain barrier!

Placental Drug TransferMembranes of the placenta keep circulation of mother and fetus separate, however it is not an absolute barrierDrugs that pass the placenta can cause significant birth defects

Protein BindingDrugs most often form reversible bonds with proteins in the bodyProtein Albumin is the most common, it makes up 50-75% of blood proteinsBecause Albumin cannot leave the bloodstream, it restricts bound drugs from reaching their sites of

Patient Safety

SourcesAbbot, N. J. (2009). Structure and Function of the Blood-Brain Barrier. Medline.