Lec 56: Pharmacokinetics II Flashcards Preview

Fundamentals > Lec 56: Pharmacokinetics II > Flashcards

Flashcards in Lec 56: Pharmacokinetics II Deck (11):
1

What are the benefits of administering a constant IV of a drug versus a single oral dose?

1. The drug avoids first pass metabolism
2. Drug is more efficiently absorbed into the bloodstream

2

What are the drawbacks of administering a constant IV of a drug versus a single oral dose?

It takes longer for the drug to reach effective concentration in the blood

3

Approximately how long does it take for a drug to reach steady state concentration after the first dose (in half lives)?

4-5 half lives

4

What is the formula for accumulation factor?

Accumulation factor = 1/fraction lost in one dosing interval

5

If a drug is given once every half-life, what is the accumulation factor?

Accumulation factor = 2

6

What are the three key things the patient must know about the drugs he/she is prescribed?

1. How much
2. How often
3. What form

7

What is the therapeutic range of a drug?

The concentration of drug that is in between the maximum safe concentration and the minimum effective concentration

8

When we prescribe medications why do we aim for between 1/2 the therapeutic range and the minimum therapeutic range? Why not use the whole therapeutic range?

Once the drug concentration goes above half the therapeutic range, side effects are more prevalent

9

What is the formula for dosing rate? Why is it important?

1. Dosing rate = volume of plasma cleared x concentration of drug in that volume
2. Dosing rate determines how much drug you should administer/ time (usually in mg/hr) to maintain steady state concentration

10

If the half life of drug is <4 hours is periodic dosing or constant infusion more appropriate?

constant infusion

11

What is the formula loading dose? When is it used?

1. Loading dose = Volume of distribution x Target concentration
2. Essentially just a big dose of a drug that will bring the concentration up to effective levels in a hurry

Decks in Fundamentals Class (66):