# 7 - Pharmacokinetics Flashcards Preview

## Pharm > 7 - Pharmacokinetics > Flashcards

Flashcards in 7 - Pharmacokinetics Deck (22)
1
Q

Key PK properties of a drug

A

Bioavailability
Vol. of dist.
Clearance
Elimination of Half life

2
Q

Volume of distribution

A

An apparent volume that would be necessary in order to account for the initial plasma drug conc. Following a dose of the drug

Units of volume or volume per unit body weight

3
Q

How to calculate volume of distribution in an animal

A

Concentration = Dose/plasma conc.

4
Q

What does volume of distribution allow you to predict

A

Peak plasma concentration of a drug at a given dose in an animal

5
Q

When rate of drug movement from blood into tissues is less than rate of drug movement from tissues into blood, is the vol of dist. Large or small.

A

Very small

6
Q

3 things that can change Vol D

A

Body fat
Poor tissue perfusion
Reduction in plasma proteins

7
Q

1st order kinetics vs. 0 order kinetics

A

0 order: animal eliminates fixed amount per unit time

1st order: drug eliminated at exponential rate

8
Q

1st order kinetics properties

A

Fixed fraction of drug is eliminated per unit time
Can convert to 0 order if the elimination process is saturated
Elimination is proportional to concentration

9
Q

Half life

A

A 3 part video game that has left everyone on a cliffhanger for the last 5+ years….damn you valve.

10
Q

Half life

A

Time required to eliminate one half of drug present in plasma
-simple units of time
-constant for 1st order drugs
Inversely proportional to the elimination rate constant

11
Q

What is the number of half lives for a drug to be generally considered eliminated

A

5 half lives

12
Q

What are the two phases uses in all PK estimations

A

1: redistribution phase
2: Elimination phase

13
Q

What phase do you use while calculating half life

A

Base it off of elimination phase

14
Q

If a drug was administered IV what is the bioavailability

A

100%

15
Q

How to find initial plasma concentration when not given

A

Follow the elimination phase line back to the initial time

16
Q

Is half life used for drug concentration in tissue

A

No

17
Q

What does the time to achieve steady state of drug conc in plasma depend on

A

Half life of the drug

18
Q

About how many half life’s does it take for a drug to reach steady state

A

5

19
Q

Steady state levels of peak and trough are determined by

A

Drug dose and dosing frequency interval

20
Q

Calculation of CpMAX for multi dose

A

=Dose X F X R / VD

Same as single dose except R is included

21
Q

R in the Multidose treatment formulae

A

Ratio of dose interval/ interval half life

22
Q

Peak to trough ratio

A

Fucntion of dose interval relative to half life

When dose interval equals Half life, CpMIN = 1/2 CpMAX