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
Understand how they got the answers on slide 7
omfg
Why does albumin concentration go down when you have a burn?
- When you have a burn, you lose skin
- Fluid comes out of burn
- Albumin is in the fluid (you are losing lots of albumin with burns)
Why does albumin concentration go down in renal failure?
-In renal failure, the kidney becomes leaky and you get leakage of these proteins and you pee out the proteins. Hence, albumin levels are reduced
Why does albumin level decrease in cirrhosis?
-Albumin is made in the liver so when the liver is failing, albumin is not being made.
With conditions: renal failure, chirrosis, burns, and pregnancy - Albumin levels _____
decrease
*see page 8
With conditions: renal failure, burns, stress/trauma, obesity, and MI - AAG (alpha 1 acid glycoprotein) levels ____
increase
*see page 8
For _____ protein bound drugs, a 5% change in protein binding is a lot.
highly
For _____ protein bound drugs, a 5% change in protein binding is not a lot.
intermediately
As we increase protein binding, we increase ______
half-life
