Final: Pharmacokinetics and Pharmacodynamics

Question 1

Pharmacokinetics

Answer 1

The study of the movement of drugs through the body
What does the body do to the drug?

Question 2

Pharmacodynamics

Answer 2

The interactions between medications and target cells, body systems, and organs to produce effects
What does the drug do to the body?

Question 3

What are the phases of pharmacokinetics?

Answer 3

Absorption
Distribution
Metabolism
Excretion

Question 4

Barriers to enteral absorption

Answer 4

Epithelial cells lining the GI tract
Patterns of absorption
Highly variable
Solubility/stability of the drug
Gastric and intestinal pH
Gastric emptying time (Gastric bypass PT)
Presence of food
Co-administration of other drugs
Coatings on the drugs

Question 5

Advantages of enteral absorption

Answer 5

Easy
Convenient
Safe

Question 6

Disadvantages of enteral absorption

Answer 6

Variability of absorption
Requires patient cooperation

Question 7

IV advantages

Answer 7

Rapid onset
Control of level of the drug
Ability to administer large volumes of fluid

Question 8

IV disadvantages

Answer 8

Expensive
Inconvenient
Cannot take it back
Infection
Fluid overload
Embolism

Question 9

IM/SubQ advantages

Answer 9

Good for meds with poor water solubility
Fast and slow

Question 10

IM/SubQ disadvantages

Answer 10

Discomfort
Inconvenient
Can be painful
Infection
Nerve damage
Affected by blood flow to area

Question 11

What is distribution?

Answer 11

Movement of drugs throughout the body

Question 12

Factors that affect distribution

Answer 12

Blood flow
Ability to exit the vascular system
Ability of the drug to enter the cells

Question 13

What are the two pathological conditions in which low regional blood flow can affect drug therapy?

Answer 13

Abscesses and Tumors

Question 14

What is the blood brain barrier?

Answer 14

Protects the brain from “foreign substances” in the blood that may injure the brain

Question 15

What is the first pass effect?

Answer 15

Rapid inactivation of some oral drugs as they pass through the liver after being absorbed
Parenteral administration will bypass this affect

Question 16

What factors affect the metabolism of drugs?

Answer 16

First pass effect
Nutritional status
Competition between drugs

Question 17

Primary route for removing drugs from body?

Answer 17

Renal excretion

Question 18

What are the non-renal routes of drug excretion?

Answer 18

Breast milk
Bile
Lungs
Sweat and saliva

Question 19

What is half life?

Answer 19

Time required for the amount of drug in the body to be decreased by half
Determines frequency of dosing (dosing interval)

Question 20

Drugs with a _____ half life need _____ dosing interval

Answer 20

Drugs with a SHORT half life need SHORT dosing interval

Question 21

Peak

Answer 21

The highest level of drug. Up to an hour after the drug is finished infusing, need to draw the peak level

Question 22

Trough

Answer 22

The lowest level of drug. Need to draw trough level 30 minutes before their next dose

Question 23

Minimum effective concentration (MEC)

Answer 23

Medication dosing attempts to regulate medication responses to maintain plasma levels between the minimum effective concentration (MEC) and the toxic concentration

Question 24

Loading dose

Answer 24

Used when plateau must be achieved quickly
It is a higher dose than typically used

Question 25

Maintenance dose

Answer 25

Smaller doses used once plateau is achieved

Question 26

Agonists

Answer 26

Drugs that occupy receptors and activate them

Question 27

Antagonists

Answer 27

Drugs that occupy receptors but do not activate them. Antagonists block receptor activation by agonists

Question 28

Maximal efficacy

Answer 28

Largest effect that a drug can produce

Question 29

Potency

Answer 29

Amount of drug given to elicit an effect