Non-linear PK

Question 1

what are the hallmarks of capacity-limited metabolism?

Answer 1

• drug elim doesn’t follow first-order kinetics (nonlinear elim)
• the elim half-life changes as dose is increased
  -saturation of one drug may be affected by other drugs
  -the composition and/or ratio of drug metabolites may change when the dose is changed

Question 2

in nonlinear PK, what is Vmax equivalent to?

Answer 2

maximum elimination rate

Question 3

in nonlinear PK, what does Km stand for?

Answer 3

enzyme capacity/affinity

Question 4

if Km is fixed, what is the relationship between Vmax and decay time? (larger or smaller Vmax)

Answer 4

a larger Vmax will make the decay time shorter

Question 5

thinking conceptually, with a fixed Km, if Vmax is doubled, what happens to decay time?

Answer 5

it takes half the amount of time to decay

Question 6

if Vmax is fixed, what is the relationship between Km and decay time? (larger or smaller Km)

Answer 6

a smaller Km means a shorter decay time

Question 7

how is half-life dependent on dose?

Answer 7

larger doses will cause a longer half-life

Question 8

we can assume at steady state that the rate of drug metabolism is ________ the dosing rate

Answer 8

equal to

Question 9

in non-linear PK, the slope at steady state is equivalent to?

Answer 9

Km/Vmax

Question 10

in non-linear PK, the y-intercept at steady state is equivalent to?

Answer 10

1/Vmax

Question 11

****LEARN THE MATH

Answer 11

.