transfer of drug from blood to extravascular fluids and tissues by systemic circulation.

70 kg, 5 L of blood, 3 L of plasma.

Cardiac Output = 0.08 L/min. x 89 beats/min

Generally rapid through fine capillaries; most drugs permeate easily but depends on the physicochemical nature of the drug and the cell membrane (favors lipid-soluble drugs)

CNS and muscles; surrounded by lineal cells.

“blood-brain barrier” – thick lipid membrane that prevents absorption of drugs.

glomerular and gut mucosa.

Liver and Bone Marrow.

Drugs can easily pass through these capillaries.

Liver is very permeable and allows passage of high MW molecules. (True/False)

Pressure gradient from arterial end entering the tissue and venous capillaries leaving the tissue

If high, liquid leaves capillaries; if osmotic pressure is higher, liquid enters; if in equilibrium, stays inside capillaries

High pressure at the arterial end of the capillary

Lower pressure of the venous blood compared to tissue fluid.

Tissue with highest blood flow will rapidly equilibrate with the drug (True/False)

Onset and intensity of drug action is influenced by initial distribution and total dose of drug (True/False)

Rate of free drug that reaches receptor site (MEC)

Total drug concentration at receptor and no. of receptor sites

Duration of drug action depends on rate of drug elimination (True/False)

important factor in determining initial distribution of drugs.

Rate-limiting step in distribution

What are the Physiologic condition where permeability is altered

Alter permeability of skin and allow drugs to permeate inward or outward

inflammation increases permeability; dangerous

Depends on blood and tissue affinity (can be reversed.

Accumulates on tissue

Accumulates on lipid tissue

formation of drug-protein complexes.

weaker bonds like hydrogen or van der waals.

Chemical activation; covalent bonding; accounts for drug toxicity

Widely distributed group of globular plasma protein (58%) from liver.

Responsible for maintaining osmotic pressure

Elimination half life = 17-18 days; major component responsible for reversible drug binding

Binds basic (cationic) drugs and is highly lipophilic

what is the leve of plasma in amino acid glycoprotein.

lipid and protein complexes classifying according to density and separation in centrifuge.

transport of plasma lipids and binding of drugs if the albumin becomes saturated.

Binds both endogenous and exogenous compounds

What is the plasma concentration present in erythrocytes.

low capacity but high affinity for endogenous substances transport.

Drug is less than the binding capacity of albumin; includes majority of useful clinical agents

Drugs exceed the number of binding sites

when class II is administered simultaneously