Lecture 33

Question 1

Difference between maintenance doses and loading dose

Answer 1

Maintenance dose is to maintain the plasma concentration within specified range over long periods of therapy
Loading dose is used to achieve a target plasma level rapidly.

Question 2

3 Factors that determine dosing plan

Answer 2

• Therapeutic window
• Clearance
• Vd

Question 3

Dosing rate at steady state equation

Answer 3

Dosing rate at ss = (CL * C) / F

F = bioavailability

Question 4

Maintenance dose equation

Answer 4

Maintenance dose = dosing rate * dosing interval

Question 5

Concentrate at steady state equation for continuous IV infusion

Answer 5

Css = infusion rate / CL

• Rate of drug infusion = rate of drug elimination
• CL is constant for first-order drugs, so Css is proportional to infusion rate

Question 6

Loading dose equation

Answer 6

Loading dose = (Vd * TC) /F

Question 7

Fixed dose with multiple IV injection result in……….

Answer 7

fluctuation in plasma level of drug, but half life is the same (4 half lives to reach steady state)

Question 8

What happens to drug concentration when given smaller doses at shorter intervals?

Answer 8

amplitude of fluctuation decreases, but drug concentration at steady state and the rate at which steady state is approached are not affected by dosing interval

Question 9

How does graph of oral administration look like?

Answer 9

more rounded peak

Question 10

How can you change the rate of absorption of oral administration?

Answer 10

by changing the formulation of tablets or capsules

• rapid release formulation
• slow release formulation (allow less frequent administration of drugs with short half lives)

Question 11

For multiple oral administration, oscillations in plasma concentration are influenced by? (2)

Answer 11

rate of drug absorption and rate of drug elimination