Pharmacokinetics

Question 1

What is pharmacodynamics?

Answer 1

What the drug does to the body

Question 2

What is pharmacokinetics

Answer 2

What the body does to the drug

Question 3

What are the four domains of pharmacokinetics?

Answer 3

1. Absorption of a drug
2. Distribution of the drug to the site of action in the body
3. Metabolism of the drug to an active or non-active metabolite
4. Elimination of the drug from the body

Question 4

What is the function of the cell membrane?

Answer 4

1. The cell membranes structure makes it relatively impermeable to large, highly polar molecules

Question 5

What is passive diffusion

Answer 5

It is how most drug move

Question 6

What will affect the state of ionization in a drug?

Answer 6

1. Differences in pH

Question 7

What is facilitated diffusion?

Answer 7

1. Carrier mediated process

Question 8

What is active transport?

Answer 8

1. Requirement of energy to move a solute against an electrochemical gradient

Question 9

What is absorption

Answer 9

Movement of drug from its site of administration into circulation

Question 10

What is bioavailability

Answer 10

1. Fractional extent to which an administered dose of a drug reaches systemic circulation

Question 11

Where are most drug absorbed?

Answer 11

1. The small intestine

Question 12

What does majority of drug absorption from the GI tract happen by?

Answer 12

Passive diffusion

Question 13

Where are weak acids (pH 1-2) better absorbed?

Answer 13

From the stomach

Question 14

Where are weak bases (3-6) better absorbed?

Answer 14

Intestine

Question 15

What do the villi of the upper intestine provide?

Answer 15

1. A larger surface area than the stomach
   *The rate of absorption from the intestine will be greater than from the stomach

Question 16

Where does sublingual administration absorb to?

Answer 16

1. To the SVC
   *will by-pass the first effect

Question 17

What effects distribution of a drug to a specific site?

Answer 17

1. Rate of blood flow to individual organs or compartments
2. Capacity of organ/ region to interact with drug

Question 18

What are factors that affects distribution into the tissues?

Answer 18

1. Cardiac output
2. Regional blood flow
3. Capillary permeability
4. Tissue volume

Question 19

What type of drugs does albumin bind?

Answer 19

1. Acidic drugs

Question 20

What type of drug does alpha 1- acid glycoprotein bind?

Answer 20

1. Basic drugs

Question 21

What does lipophilic and BBB relate to each other?

Answer 21

1. The more lipophilic a drug, the more likely it is to cross the BBB

Question 22

What are other things that can affect drug distribution?

Answer 22

1. Tissue binding
   *Drugs can accumulate in certain tissue increase in either duration of action or potential for toxicity
2. Redistribution
   *drug goes for site of action to other tissues
   *usually happens with very lipophilic drug administered as a rapid bolus

Question 23

Are lipophilic drugs easily passed for elimination?

Answer 23

1. No
   *there needs to be metabolism of lipophilic drugs to more hydrophilic metabolites

Question 24

What is zero order kinetics?

Answer 24

1. A constant amount of drug is metabolizes per unit of time

Question 25

What is first order kinetics?

Answer 25

1. Amount of drug metabolized per unit of time is proportional to the plasma concentration of the drug
   *the rate of drug metabolism depends on drug concentration in the body

Question 26

Where does bio transformation of drugs into more polar hydrophilic metabolites happen?

Answer 26

In the liver

Question 27

What is the rate at which some CYP metabolize drugs based no?

Answer 27

Genetics
*pharmacogenomics

Question 28

where is the most common place for elimination of drugs?

Answer 28

Renal (kidneys)

Question 29

What is steady state?

Answer 29

1. When the rate of drug elimination equals the rate of drug administration
   *dosing rate=clearance rate X [steady state]

Question 30

What is volume of distribution?

Answer 30

1. Relates to the amount fo drug in a body compartment to the concentration in the blood or plasma

Question 31

What does a high V4 mean?

Answer 31

Lots of tissue binding or high distribution into fat

Question 32

What does low v4 mean?

Answer 32

Generally water soluble and distributes mostly into plasma

Question 33

What does loading dose mean>

Answer 33

1. A larger than normal dose to achieve a desired concentration in the blood at a much quicker rate