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Flashcards in Factors that complicate Pharmacokinetics Deck (12):
1

What are the two factors that complicate pharmacokinetics?

unusual drug behaviour and inter patient variability

2

When is variation in pharmacokinetics an issue?

when the drug has a narrow therapeutic window

3

What are the three ways that a drug can have unusual behaviour?

low bioavailability, slow distribution, drug saturates elimination processes

4

What is the problem with low bioavailability?

there will be a big variation in the amount of drug that reaches its destination

5

How do you deal with a drug with low bioavailability?

use another route of administration

6

What is the problem with slow distribution?

get a peak concentration that is much higher than normal

7

How do you deal with a drug with slow distribution?

give several smaller doses rather than one big dose

8

What is the problem with a drug which saturates elimination processes?

steady state is never reached with multiple dosing and increasing dose rate leads to disproportional increase in concentration

9

How do you deal with a drug which saturates elimination processes?

adjust and monitor dose

10

What causes inter patient variability?

age, genetic factors, disease, drug-drug interactions

11

How does age cause inter patient variability?

renal function is different and phase I and phase II metabolism is different

12

What are the two types of drug-drug interactions?

pharmacodynamic (no affect on concentration) and pharmacokinetic (affect on concentration)