Week 1 (Cont)

Question 1

The study of the bodily processes that affect the movement of a drug in the body.

Answer 1

pharmacokinetics

Question 2

What are the four fundamental pathways of drug movement in the body?

Answer 2

Absorption, distribution, metabolism, and excretion.

Question 3

What must a drug reach to cause a therapeutic response?

Answer 3

Adequate concentrations in the blood.

Question 4

What is the peak serum concentration?

Answer 4

The highest amount of drug in the blood after administration.

Question 5

What is the half-life of elimination (t1/2)?

Answer 5

The time it takes for the serum concentration of a drug to fall by one half.

Question 6

The transfer of a drug from its site of administration to the bloodstream.

Answer 6

absorption

Question 7

What factors affect drug absorption?

Answer 7

• Route of administration
• Formulation and chemical properties of the drug
• Physiologic factors

Question 8

The relationship between the drug dose and the amount ultimately delivered to the bloodstream, expressed as a percentage?

Answer 8

bioavailability

Question 9

The significant metabolism of a drug during its first passage through the liver after oral administration?

Answer 9

first-pass effect

Question 10

What is the primary site of drug absorption after oral administration?

Answer 10

The small intestine.

Question 11

What can significantly impair drug absorption?

Answer 11

Removal of sections of the small intestine.

Question 12

How does blood flow affect drug distribution?

Answer 12

Higher blood flow to vital organs results in greater drug delivery to those organs.

Question 13

A significant barrier that protects brain tissue from many drugs, requiring drugs to be small and lipid-soluble to penetrate.

Answer 13

blood-brain barrier

Question 14

What is the role of albumin in drug distribution?

Answer 14

Albumin binds to drugs in the bloodstream, affecting their distribution into tissues.

Question 15

Fill in the blank: The time it takes for the serum concentration of a drug to fall by one half is called the _______.

Answer 15

half-life.

Question 16

True or False: Liquid formulations of drugs require dissolution before absorption.

Answer 16

False.

Question 17

What are factors that can reduce drug bioavailability after oral administration?

Answer 17

• Acid environment in the stomach
• Presence of food
• Metabolism in the liver

Question 18

What affects drug distribution into tissues?

Answer 18

Binding to plasma proteins

Only unbound drug can penetrate tissues and exert activity.

Question 19

What role does albumin play in drug administration?

Answer 19

Acts as a reservoir of an administered drug

Albumin helps maintain a balance between free and bound drug.

Question 20

What happens when albumin levels are low in patients using highly protein bound drugs?

Answer 20

May lead to toxicity due to increased free drug

Fewer binding sites result in more unbound drug available.

Question 21

How do two highly protein bound drugs interact?

Answer 21

They compete for binding sites on albumin

The drug with greater affinity binds first, affecting the availability of the second drug.

Question 22

What factors can affect the apparent volume of distribution (Vd) of a drug?

Answer 22

Body composition, cardiac decompensation, age

These factors influence the appropriate drug dosage.

Question 23

What is the formula for calculating the volume of distribution?

Answer 23

Vd = Dose / Cp

Where Cp is the serum concentration.

Question 24

What are the three compartments of total body water?

Answer 24

• Intracellular fluid
• Extracellular fluid
• Plasma volume

Total body water is about 60% of body weight.

Question 25

Why do small, highly lipophilic drugs have a large apparent volume of distribution?

Answer 25

They tend to distribute widely in body tissues ## Footnote In contrast, hydrophilic drugs remain in the circulatory system.

Question 26

Why is dosing in infants and children different from adults?

Answer 26

Children have different body composition and organ maturity ## Footnote They have higher water content and lower muscle and fat.

Question 27

The process of chemical changes for easier excretion?

Answer 27

biotransformation ## Footnote This is also known as metabolism.

Question 28

What is the major site for drug metabolism?

Answer 28

The liver ## Footnote Other tissues may also contribute to drug biotransformation.

Question 29

What happens to highly fat-soluble drugs in the kidneys?

Answer 29

They are reabsorbed instead of being excreted ## Footnote These drugs must be metabolized to water-soluble forms first.

Question 30

What are the two types of metabolic processes drugs undergo in the liver?

Answer 30

* Oxidation-reduction reactions * Conjugation reactions ## Footnote Most drugs undergo one or both types of reactions.

Question 31

A common conjugation reaction making drugs more water-soluble

Answer 31

glucuronidation ## Footnote It aids in excretion by the kidneys.

Question 32

An inactive compound converted to an active form by metabolism?

Answer 32

prodrug ## Footnote Example: Fosphenytoin is a prodrug of phenytoin.

Question 33

How does age affect drug metabolism?

Answer 33

Organ function declines with age ## Footnote Elderly may poorly tolerate drugs requiring metabolism.

Question 34

What is steady state in drug dosing?

Answer 34

The point where drug intake equals drug elimination ## Footnote Drug levels remain constant unless changes occur.

Question 35

What factors affect drug excretion?

Answer 35

* Liver function * Kidney function * Age ## Footnote Reduced function can require dosage adjustments.

Question 36

Why is it important to monitor steady state serum drug levels?

Answer 36

To ensure appropriate drug response ## Footnote Adjustments may be needed based on therapeutic effects.

Question 37

What complications arise from reduced kidney or liver function?

Answer 37

Drugs may accumulate in the body ## Footnote This can lead to toxicity and requires careful dose selection.

Question 38

What is the role of the kidneys in drug elimination?

Answer 38

Filter blood and create urine for waste removal ## Footnote Non-bound drug molecules are filtered out into the glomerular filtrate.