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Flashcards in Pharmacokinetics Deck (56)
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1

name the two general types of transport

-transcellular transport
-intercellular transport

2

name ways of transversing a cell membrane

-diffusion
-filtration
-facilitated diffusion
-active transport
-pinocytosis

3

whats the most common and important mode of transversing biological mambranes

diffusion

4

in which direction does diffusion go

down the cc gradient

5

what significantly influences diffusion

-lipid-water partition of drug
-thiccness of the cell membrane

6

how does the pk value influence drug transport

-different pk values will diffuse differently

7

the cc gradient affects the rate of filtration t/f

t

8

does facilitated diffusion requ. E ?

no

9

is facilitated diffusion saturable

yes

10

describe active transport

-requ. energy
-against cc gradient
-occurs only in one direction
-is saturable

11

describe the phases of absorption

1 - administration
2 -has to be taken up into bloodstream
3 - uptake into target organ

12

what could reduce compound absorption

- poor solubility
-chemical instability in stomach
-ianbility to penetrate int. wall

13

define bioavailability

the fraction of drug that reaches the bloodstream unaltered
-measrement of the extent of a therapeutically active drug that reaches systemic circulation and is available @ site of action

14

define absolute bioavailability

availability of active drug in circulation after non -IV admin.

15

what is the absolute bioavailability of drug admin. IV

1

16

name factors influencing bioav. (7)

-absorption rate
-degradation or metabolism of drug prior to hepatic absorption
-first pass effect
-food taken with p.o. admin
-other drugs
-intest. mot.
-liver state

17

is distribution reversible

yes

18

what does distribution depnd on

-permeability between tissues
-blood flow and perfusion rate
-ability of drug to bind to plasma proteins and tissues

19

rank the flow of the organs liver, bone, fat, skin, muscle, kidney, brain

brain, liver, kidney>muscle, skin> fat, bone

20

factors affecting drug distr.

-dose
-admin.
-membrane permeabilty
-blood perfusion
-lipid solubility
-ph-pka
-plasma protein binding
-intracellular binding

21

how do drugs travel in plasma

free or bound to plasma proteins

22

the drug plasma protein binding is always at least 10%

f

23

name the main points of plasma protein binding

-generally reversible
-only the free drugs diffuse through capillary walls
-extensive binding may prolong duration of action
-some plasma proteins bind many different drugs some just one
-changes in PPB can lead to change in drug effect

24

what is the volume of distr.

VD= volume of total body fluid in which the drug appears to be distributing

25

how would you calculate the vd

amount of drug administered/initial plasma cc

26

for the majority of the drugs the vd is an accurate representation of their actual distribution t/f

f

27

the lower the VD of a drug the more it spreads through the body t/f

f

28

What does a low VD indicate in regards to PPB

extensive plasma protein binding

29

A very high VD may indicate extensive tissue binding t/F

t

30

what ends the pharmacological acion of a parent drug

biotransformation