Pharmacokinetics (L8)

Question 1

why do we need to be able to calculate kinetic parameters?

Answer 1

to ensure the dosage regimen results in the correct plasma concentration in all patents irrespective of:
• disease state 
• capacity to eliminate 
• route of administration 
• age 
• other drug therapy

Question 2

what is bioavailability?

Answer 2

fraction absorbed into systemic circulation

Question 3

what is volume of distribution?

Answer 3

space available to contain drug

Question 4

what is elimination half-life?

Answer 4

rate of removal

Question 5

what is clearance?

Answer 5

efficiency of removal

Question 6

what is Css?

Answer 6

plasma concentration at steady state

Question 7

what are kinetic orders?

Answer 7

relate the plasma concentration of a drug and its rate of elimination from the body

Question 8

first order kinetics

Answer 8

decrease in drug is dependent on the plasma concentration

concentration of drug is the rate limiting factor

exponential decrease

straight line of log scale for plasma drug concentration

Question 9

zero order kinetics

Answer 9

decrease in drug is independent of the plasma concentration

rate is constant

straight line down

Question 10

saturation kinetics of alcohol

Answer 10

concentration falls linearly rather than exponentially - zero order kinetics

rate of fall doesn’t vary with dose

alcohol dehydrogenase becomes saturated at very low alcohol concentrations