Nurs 605 Module 1

Question 1

What is pharmacokinetics?

Answer 1

how the body acts on the drug
specifically absorption, distribution, metabolism and excretion
used to individualize doses of drugs

Question 2

What is pharmacodynamics?

Answer 2

how the drug acts on the body

what are the drugs mechanisms of actions on the body

Question 3

Describe absorption

Answer 3

process of drug movement into the bloodstream

how fast the drug leaves the area of entry (oral, IV, IM) and what is the extent of this on the body

Question 4

What is bioavailability?

Answer 4

percentage of the drug that reaches the bloodstream intact

Question 5

Describe factors that affect absorption of a drug

Answer 5

formulation of the drug
pH of the body
acidity of the stomach
food, solubility

Question 6

What are some routes of drug administration?

Answer 6

intravascular- intravenous or intraarterial

extravascular- oral, SL, IM, SQ, dermal, rectal

Question 7

What is the first pass effect or first pass metabolism and how can it be avoided?

Answer 7

describes the drug “first passing” through the liver prior to reaching systemic distribution
greatly decreased the bioavailability of the drug
can be avoided by using routes that reach systemic circulation immediately ie) IV routes

Question 8

Define evidence based medicine

Answer 8

using and applying best scientific evidence, clinical expertise, clinical expertise and patient specific values in order to guide decisions for individual patient care

Question 9

Why is evidence based medicine necessary?

Answer 9

many "claims" out there that are not relevant
guides clinical decision making 
what is best for your patient
making informed decisions 
rarely one best answer that fits all

Question 10

What is the evidence based medicine process?

Answer 10

identify problem
what is necessary to answer the question/problem
find current evidence -primary literature
evaluate the evidence
apply evidence to patient
evaluation

Question 11

Define null hypothesis

Answer 11

assumption that there is no difference in treatment between group A and B
two treatments are equal

Question 12

Define alternative hypothesis

Answer 12

opposite of null hypothesis

there is a difference in treatment between group A and group B

Question 13

What does it mean to reject a null hypothesis?

Answer 13

that means there is a difference in treatment between group A and group B
rejection=there is a difference

Question 14

Define internal validity

Answer 14

how accurate a study is in measuring what its supposed to measure

Question 15

Define external validity

Answer 15

the study results are generalizable to the population outside of the study

Question 16

Define sensitivity

Answer 16

a patient that is positive for a diagnosis will test positive

Question 17

Define specificity

Answer 17

individuals without the specific condition will test negative for the condition

Question 18

Define odds ratio

Answer 18

the ratio is the odd of developing a condition in an exposed group versus the odds of developing a condition in a non exposed group

Question 19

What does it mean when an odds ratio is =1 ?

Answer 19

odds ratio =1 means the condition studied is likely to occur in both groups (ie group A and B)

Question 20

What does it mean when an odds ratio is >1 ?

Answer 20

odds ratio > 1 means that the outcome is associated with the exposure or a ‘positive association’

Question 21

Define relative risk

Answer 21

the risk of developing a condition when one is exposed vs. not exposed
ratio of risk of an event in people with a specific characteristic to those without the characteristic

Question 22

Define relative risk reduction

Answer 22

proportional reduction in rates of bad events between experimental and control groups
what was the percentage of risk that was “reduced”
easier to visualize

Question 23

Define relative risk reduction

Answer 23

proportional reduction in rates of bad events between experimental and control groups
what was the percentage of risk that was “reduced”
easier to visualize
must use relative risk reduction otherwise statistics on certain treatments can be misleading

Question 24

Define distribution

Answer 24

movement of one drug from one part of the body through another
influenced by various factors

Question 25

What is the rate of distribution and what are the factors that affect this?

Answer 25

rate of distribution is the speed by which one drug leaves one part of the body to another
influenced by: tissue/capillary perfusion-greater perfusion to an area means greater drug distribution
membrane permeability: certain membranes are tighter than others and allow drugs to pass through easily. blood brain barrier is tight membrane therefore allows less drug to pass through
affinity of the drug for tissues: dependent on the drug, hydrophilis vs. lipophilic (lipophilic drugs will pass fatty tissue easier than hydrophilic drugs)

Question 26

What is the extent of a drug binding?

Answer 26

part of drug distribution
binding of drugs = bound drugs
drugs not bound= free drug
free drug will pass through different membranes and compartments such as blood/plasma and bind to proteins, there is an equal amount in order to reach accurate concentration

Question 27

What is CYP450 and what is its action?

Answer 27

CYP450 is an enzyme in the liver that metabolizes most drugs
different enzymes metabolize different things
primarily works on drugs by removing or adding polar groups to the metabolized drug in order for it to be excreted by the kidneys
enzyme inhibitors=stops CYP450=stops metabolism=increased concentration of drug in the bloodstream
enzyme inducers = activates CYP450, makes it work faster= metabolism occurs faster=decreased levels of drug in the bloodstream

Question 28

What are some factors that can affect drug metabolism?

Answer 28

route of drug
age/gender
nutritional status (low protein = less enzymes; less carbs=less ATP)
enzyme inducers and inhibitors 
disease states

Question 29

What is P-glycoprotein?

Answer 29

transport protein molecule

uses active transportt (ATP) to transport molecules into the urine, bile, etc for elimination

Question 30

Describe half life (T1/2)

Answer 30

half life of a drug is the time it takes for 1/2 of the drug to be eliminated from the body

Question 31

What is the relationship between steady state and IV infusions?

Answer 31

steady state is achieved with 95% of drug reaches the concentration of steady state
this occurs with IV drugs as there is a constant amount of drug in the blood

Question 32

How many half lives does it take to completely eliminate a drug from the plasma or reach steady state with IV infusions?

Answer 32

4-5 half lives

Question 33

Describe receptors

Answer 33

drugs acts on receptors in the body to block or illicit a biological response

Question 34

Define agonist

Answer 34

agonists are drugs that bind to receptors and illicit a biological response

Question 35

Define antagnoist

Answer 35

antagonists are drugs that block the receptors so bioloical responses do not occur

Question 36

Define receptor upregulation

Answer 36

receptors can regulate themselves

upregulation means that there is little receptor or the receptors are contsatnly blocked so the body creates more

Question 37

Define receptor downregulatio

Answer 37

downregulation means that the receptors are always being stimulated