Distribution Flashcards
Body Fluid Compartments:
Total body water = __% of body weight
60
Body Fluid Compartments:
Intracellular fluid = __% of body weight
40
Body Fluid Compartments:
Extracellular fluid = ___% of body weight
20
Body Fluid Compartments:
Plasma fluid = ___% of body weight
4
Body Fluid Compartments:
Blood volume = ___% of body weight
7
The body fluid compartments % are based on if the drug gets into the RBC.
If it doesn’t get into the RBC then use ____% instead of 60% for total body water
57
Go over the questions on page 1
okay jose
Following absorption the pattern of drug distribution is governed by the rate of _____ ______ (______) to each tissue and the affinity of the drug to accumulate in the tissue.
blood flow (perfusion)
Tissues that receive the _____ blood flow will rapidly equilibrate with the drug, whereas tissues that are poorly perfused with equilibrate _____ with the drug.
highest
slower
Blood flow is an important factor in determining the ____ ______ of drugs.
initial distribution
Explain how you can have 0% blood concentration level of a drug but still get a therapeutic effect.
- Organ can take the drug in but won’t kick it out
- Drug will accumulate solely in the organ (not the blood) and elicit the drug response.
Drug accumulation into tissues is dependent upon what 2 things?
1) blood flow
2) tissue affinity for the drug
Tissue concentration of drugs with ____ tissue affinity will equilibrate rapidly with the plasma drug concentration and decline rapidly as the drug is eliminated from plasma.
low
Conversely, drugs with high tissue affinity tend to _____ or _____ in the tissue.
accumulate or concentrate
Highly ____ drugs are extracted by poorly perfused organs (ex. fat) hence drug accumulation is slow.
lipophilic
Removal from fat tissue for lipophilic drugs is also extremely ____.
slow
List some tissues that are highly perfused
adrenals kidneys thyroid liver portal-drained viscera heart (basal) brain
List some tissues that are poorly perfused
skin
muscle (basal)
connective tissue
fat
What is the formula for Vd (volume of distribution)
Volume (L) = Amount of drug added (mg)/ Drug conc (mg/L)
What is the lowest apparent Vd of a 70 kg healthy male?
2.8 L (plasma volume)
understand case on slide 6
if i must
Drug bound to protein cannot ____ the cell
enter
Lipophilic drug must be ______ to enter the cell and cross the membrane.
unbound
What are the 2 proteins we are concerned about?
Albumin - acidic drugs
AAG (alpha 1 acid glycoprotein) - basic drugs
