RVT- Pharmacokinetics

Question 1

In what 4 ways does the body affect the drug administered to it?

Answer 1

Absorption- how it goes in
Distribution- how it is moved around in the body
Metabolism- how it is changed in the body
Excretion- how it goes out

Question 2

What is passive diffusion?

Answer 2

Movement of a molecule from a high concentration to low concentration. Requires no energy
No bouncer at the door/ no one inside/ busy outside….walk on in

Question 3

What is facilitated diffusion?

Answer 3

Moves from high to low concentration. No energy required
Carrier protein needed to enter cell
No one in the bar, lots of people outside, bouncer at the door

Question 4

What is active transport?

Answer 4

Movement from area of low concentration to high concentration
Requires energy and a carrier molecule
Busy in bar, empty on street. Bouncer at the door.

Question 5

What is Pinocytosis and phagocytosis?

Answer 5

Pino- cell drinking (pino noir)
Liquid molecule engulfed by the cell; Requires energy
Phago - cell eating
Solid molecule engulfed by the cell; Requires energy

Question 6

What is a weak acid drug?

Answer 6

Neutral molecule that dissociates into an ion and a proton

Question 7

What is a weak base drug?

Answer 7

A charged molecule that accepts a proton to become neutral

Question 8

What does ‘bioavailability’ refer to?

Answer 8

The % of drug that enters systemic circulation
How much actually gets there
IV = 100% bioavailability
IM = 75% bioavailability because some gets lost/stored in fat

Question 9

What affects bioavailability?

Answer 9

Blood supply to the area
Surface area
Mechanism of absorption
Dosage form= IV, IM, PO

Question 10

What does ‘Distribution’ refer to?

Answer 10

Physiological movement of the drug from the systemic circulation to the tissues.

Question 11

What affects distribution?

Answer 11

Membrane permeability
Tissue perfusion
Protein binding
Volume of distribution
Species

Question 12

A high number of drugs tend to bind with what protein?

Answer 12

Albumin

Question 13

What is biotransformation?

Answer 13

Chemical alteration of drug molecules by the body to a metabolite
ie; Prednisone to prednisolone.

Question 14

What is the primary site for biotransformation?

Answer 14

Liver

Question 15

What are the 4 mechanisms of biotransformation?

Answer 15

Oxidation ( loss of electrons)
Reduction ( gaining electrons)
Hydrolysis ( addinh H2O=splitting molecule)
Conjunction ( adding gluconic acid=water solubility)

Question 16

What is excretion? And what are its routes?

Answer 16

Elimination of the drug from the body

Routes- Kidney, Liver, intestines, lungs,milk,sweat

Question 17

In what form do the majority of acidic drugs exist in an acidic environment?

Answer 17

Nonionized

Question 18

Which animal has a greater volume of distribution?

A 7% dehydrated cat or a normal cat?

Answer 18

Normal cat

Question 19

Strength of binding between a drug and its receptor is referred to as….

Answer 19

Drug affinity

Question 20

Will giving fluids to an animal increase excretion of a drug from its body?

Answer 20

Yes

Question 21

Is hydrophilic water loving or fat loving?

Answer 21

Water loving

Question 22

‘Induce’ is a term used to describe an increase in the rate of ….

Answer 22

biotransformation by an enzyme system

Question 23

What does pharmacokinetics refer to?

Answer 23

The affect of the BODY on the drug