Pharmacokinetics

Front 1

the physiological movement of drugs within the body

how drugs are absorbed, distributed, metabolized, and excreted by the body

Back 1

What is Pharmacokinetics

Front 2

4 steps of pharmacokinetics

Back 2

absorption

distribution

biotransformation (metabolism)

excretion

Front 3

Mechanisms of drug movement

Back 3

passive diffusion

facilitated diffusion

active transport

pinocytosis/phagocytosis

Front 4

Passive Diffusion

Back 4

molecules move from an area of high concentration to an area of low concentration

does not require energy

Front 5

molecules are small, nonionic, and lipophilic in which type of diffusion?

Back 5

Passive

Front 6

Facilitated Diffusion

Back 6

a type of diffusion that uses a special molecule to help the drug molecule cross the cell membrane

Front 7

Active Transport

Back 7

a type of diffusion that uses a special carrier molecule and ATP to carry the drug molecules across the cell membrane

Front 8

Pinocytosis

Back 8

the cell membrane surrounds and engulfs liquid molecules

ie isulin

Front 9

Phagocytosis

Back 9

the cell membrane surrounds and engulfs solid particles

ie nutrients

Front 10

which methods of drug movement require energy?

Back 10

active transport and phagocytosis/pinocytosis

Front 11

Drug Absorption

Back 11

the movement of the drug from the site of administration to the bodily fluids that will carry it to the site of action

(blood/plasma)

Front 12

Drug factors that affect absorption

Back 12

drug pH

solubility

molecular size

Front 13

the degree to which a drug is absorbed and reaches circulation-the percentage that actually reaches systemic circulation

Back 13

Bioavailability

Front 14

Bioavailability of IV drugs

Back 14

1

Front 15

Bioavailability of other parenteral drugs

Back 15

<1

Front 16

First Pass Affect

Back 16

thedrug passes thru the liver first and may have extensive metabolism so themajority of the oral drug is destroyed

Front 17

Factors that affect bioavailability

Back 17

blood supply to the area of entry (mm vs

surface area for absorption

mechanism of drug absorption

Front 18

weakly acidic drugs are better absorbed where?

Back 18

the somach

Front 19

hydrophilic drugs are better absorbed where?

Back 19

the small intestine

Front 20

Patient factors that affect drug absorption

Back 20

blood flow pain stress

hunger/fasting food consumption

health age species

Front 21

The movement of drugs from systemic circulation to the tissues

-the target tissues

Back 21

Drug Distribution

Front 22

factors that affect drug distribution

Back 22

membrane permeability

tissue perfusion

protein binding

volume of distribution

Front 23

which factor of drug distribution has the greatest effect on drug distribution

Back 23

membrane permeability

Front 24

which type of drug can enter the CNS?

Back 24

Lipophilic drugs

Front 25

which body tissues exhibit rapid distribution

Back 25

brain, heart, liver, kidneys

highly perfused

Front 26

body tissues with slow distribution

Back 26

fat, skin

poorly perfused

Front 27

poorly perfused tissues...

Back 27

maintain drug levels longer bc of poor blood flow to those tissues

Front 28

some drugs bind to proteins in the blood, especially which protein?

Back 28

Albumin

Front 29

how can liver dz affect protein binding

Back 29

albumin is made in the lover, dz will reduce albumin production making less available for protein binding which can result in toxicity from the extra drug available

Front 30

Biotransformation

Back 30

metabolism

the chemical alteration of the drug by the body to a metabolite

Front 31

4 pathways of biotransformation

Back 31

oxidation

reduction

hydrolysis

conjugation

Front 32

where is the primary site of biotransformation

Back 32

the liver

Front 33

other sites of biotransformation

Back 33

kidneys

small intestines

lungs

brain

skin

Front 34

in what scenario are two drugs acting SYNERGISTICALLY?

Back 34

when 2 or more drugs administered together produce a greater response than they would individually

Front 35

in what scenario are two drugs acting ANTAGONISTICALLY

Back 35

when the administration of one drug decreases the action of another drug

Front 36

Cytochrome P450

Back 36

is a detoxifying enzyme found in the liver

when stimulated it can reduce the body's response to drugs

Front 37

Methods of drug excretion

Back 37

renal elimination

hepatic elimination

intestinal elimination

elimination in the milk

Front 38

Factors that affect biotransformation

Back 38

altered absorption

competition for plasma proteins

altered excretion

altered metabolism

Front 39

Drug Tolerance

Back 39

decreased response to a drug due to repeated use

Front 40

Dose

Back 40

the amount of a drug administered at one time

measured in a unit of mass

-tab, mls, tbsp, mg/kg

Front 41

the amount of drug and frequency of administration for a specific species

mg/kg and SID

Back 41

dosage

Front 42

Loading Dose

Back 42

the initial administration of the drug to achieve rapid therapeutic concentration

-usual IV IM or infusion

Front 43

Maintenance Dose

Back 43

administration continued throughout the remainder of the treatment period at a given interval and route

Front 44

Dose Interval

Back 44

the time between treatments

BID q12hr PRN QOD

Front 45

Pill forms

Back 45

tablets

capsules(glycerin or gelatin container)

boluses

molded tablets (chewable-heatworm)

sustained release

extracts

Front 46

rule of thumb concerning cloudy liquids

Back 46

do NOT give IV!!

Front 47

factors that alter drug metabolism

Back 47

liver dz

drug tolerance

species