Flashcards in Class 2 - IV Bolus Administration Deck (17):
What is the simplest way to describe drug distribution and elimination?
One-Compartment Open Model.
What does the One-Compartment Open Model assume?
That the drug can enter and leave the body and the body acts like a single uniform compartment.
k=km + ke
What is the volume of distribution?
A hypothetical volume of body fluid that would be required to dissolve the total amount of drug at the same concentration as that found in the blood.
What is the volume of distribution proportionally constant to?
The amount of drug in the body to the measured concentration in the biological fluid.
Vd = Db/Cp
What does a Large Vd mean?
More concentrated in extravascular tissues and less concentrated intravascularly.
If a drug is highly bound to plasma proteins or remaining in the vascular region what happens to the Cp and Vd?
Higher Cp and smaller Vd
The apparent Vd is a volume term that can be expressed as a simple volume or in terms of present body weight. In expressing the apparent Vd in terms of percent body weight, a 1-L volume is assumed to be....
equal to the weight of 1 kg
What is clearance?
A measure of drug elimination from the body without identifying the mechanism or process.
Volume of plasma that is cleared of drug per unit time.
Cl = kVd
Why do some drugs fit the multi-compartment model?
Because some drugs distribute at various rates into different tissue groups.
What are highly perfused tissue groups?
heart, brain, hepatic-portal system, kidney, and endocrine glands
Skin and muscle
Adipose tissue and marrow
What are slowly perfused tissue groups?
Bone, ligaments, tendons, cartilage, teeth, and hair.
What is the method of residuals(feathering or peeling)?
A procedure for fitting a curve to the experimental data of a drug when the drug does not clearly follow a one-compartment model.
How is residual plasma concentration obtained?
By subtracting the extrapolated line from observed data.
What is the equation to find concentration in a multi compartment drug?
Cp = Ae^(-at) + Be^(-bt)
What is beta half-life?
t1/2 = 0.693/t
There is only one volume of distribution for multi-compartment model drugs. T/F
False, there are several volume of distributions for multi-compartment models.