# Pharmacokinetics Lecture 3 IV Bolus Modeling, Plasma Curves & Data Analysis. Part I

version from 2016-07-20 21:52

## Section

Question Answer
3 approaches to modeling (1)(1) Compartment analysis
3 approaches to modeling (2)(2) Non Compartment or Statistical moment analysis
3 approaches to modeling (3)(3) Physiologically based analysis

Question Answer
T or F? Compartment analysis views body as 1 or more compartments which are interconnectedTrue, each compartment behaves the same way w/ regards to a given drug
T or F? Compartment represents real anatomical spacesFalse, In compartment, anatomical space or tissues that behaves the same way are lump together.
T or F? Compartment Analysis ff the 1st order kineticsTrue. As the drug dose increases, so also the The rate of elimination of drug is increased

Question Answer
What are the assumptions of 1 compartment model? (1)(1) Body is a single (black box), well-mixed container and drug in the body is in rapid equilibration with drug in tissue
What are the assumptions of 1 compartment model? (2)(2) Drug is instantaneously distributed throughout the body
What are the assumptions of 1 compartment model? (3)(3) 1st Order elimination - rate of change of drug concentration (dC/dt) is proportional to drug concentration (C)

Question Answer
Formula for One Compartment model for IV bolusdX/dt = -kX. If dose (x) is increased, the K is decreased because K is negative slope.
In One Compartment model, if the amount of drug or the dose of drug is doubled, the rate of change of X with time (dX/dt) is also doubled. True or False?True
Phentermine k = 0.028/hr. If Phentermine dose is doubled to 60 mg/day, you'd expect the elimination rate constant (k) to .... (a) double (b) decrease (c) stay the sameAns is DECREASE. Since K = slope, does the slope increase or decrease when dose is doubled?. Remember in Compartment model, the equation is dX/dt = -kX where the negative is an indication of loss of drug.

Question Answer
T or F? When the concentration of drug is increased, the elimination constant (k) decreasedTrue
T of F? When the concentration of drug is increased, the slope (k) of semilog plot of drug will remain the sameTrue. The k constant of slope which is not the same as K constant of elimination will remain unchanged. The k constant of elimination will decrease.
Formula for Elimination rate constant (k)k = - (slope) = [(Ln C2 - Ln C1)]/[t2-t1] OR k = -2.3(slope) = -2.3 (log C2 - log C1) / [t2 - t1]
T or F? Half-life is a reciprocal/inverse of the elimination rate constantTrue

Question Answer
Which plot is linear, the curve or the straight line?The curve
Which plot is semilogarithmic plot, the curve or the straight line?The straight line