Basics

Question 1

Pharmacokinetics

Answer 1

What the body does to the drug. 
Involves:
Absorption 
Distribution
Metabolism 
Elimination

Question 2

What the body does to the drug.
Involves:
Absorption
Distribution
Metabolism
Elimination

Answer 2

Pharmacokinetics

Question 3

Drugs doing their job at the receptor site. They bind to cellular reception sites. Drug-receptor binding is reversible, selective (affinity), and graded.

Answer 3

Mechanism of action

Question 4

This means Drug-receptor binding is selective.

Answer 4

Affinity

Question 5

Binds to a receptor site and produces a result

Answer 5

Agonist

Question 6

Binds the receptor site and blocks an activity

Answer 6

Antagonist

Question 7

Molecules can move from one side of a barrier to the other without using energy. Move down a concentration gradient from an area of high concentration to low concentration solubility of drug must match absorption site (lipophilic). Has better outcome if drug molecule is non-ionized and in same pH.

Answer 7

Passive diffusion

Question 8

Requires energy. Protein membranes of the cell can act as carrier membranes. Works if the solubility doesn’t match. But must share molecular similarities.

Answer 8

Active transport

Question 9

The fraction of the drug that reaches the systemic circulation.
Dependent on solubility, chemical structure, size, polarity, and presystemic biotransformation.

Answer 9

Bioavailability

Question 10

When taken orally, some of it will pass through the hepatic circulation through the portal vein. Sometimes it is cleared by the liver before it ever reaches the systemic circulation. Have to give a higher PO dose than IV because it has a higher first-pass metabolism.

Answer 10

First pass metabolism

Question 11

First step in pharmacokinetics. Getting into the body. Dependent on first-pass metabolism, food, surface area, and drug size.
Affected by solubility, chemical structure, polarity, route, site, bioavailability, peak blood flow,

Answer 11

Absorption

Question 12

The 2nd step in pharmacokinetics. After absorption, it is transported to its site of action. Drugs bind to proteins (usually albumin) in the circulatory system. Highly bound drugs (to protein) are less available for action. Low binding drugs have higher distribution.

Less available protein, more free drug and higher chance for toxicity.

Barriers: blood-brain barrier and placental barrier

Answer 12

Distribution

Question 13

Lack of enough Albumin. Albumin is the protein that most drugs bind to. If not enough protein, there are fewer binding sites, and there is more free drug, increasing toxicity.

Answer 13

Hypoalbuminemia

Question 14

3rd step in pharmacokinetics. Drug is where it needs to be now needs to be transformed. This is the process of chemically changing a drug to a different compound called a metabolite. Want to increase water solubility and decrease lipid solubility.
Affected by age, genetics, gender, diet, disease states.

Answer 14

Metabolism/ Biotransformation

Question 15

Found in the lipophilic ER membranes of the liver. They are involved in the biotransformation of drugs in the metabolism phase.
Enzyme Induction and Enzyme Inhibition

Answer 15

CYP450 enzymes

Question 16

4th phase of pharmacokinetics. The excretion and their transport outside the body. A drug is removed from tissues and circulation.

Renal excretion most common. Needs to be water-soluble. Removes drug that is unbound and free in plasma. Glomelular in the filtration.

Biliary excretion- transported by liver cells from blood to bile then enter GI tract and excreted through feces.

Answer 16

Elimination

Question 17

The amount of time over which the drug concentration in the plasma decreases to 1/2 of the original value. Ultimately determines how often a drug is administered. Takes 4-5 half-lives to reach steady state concentrations during continuous dosing of a drug.

Answer 17

Half-Life

Question 18

Oral route of administration. Non-ionized drugs diffuse passively down a concentration gradient for the higher Concentration (GI tract) to a lower concentration (blood)

Answer 18

Enteral absorption

Question 19

Most drugs undergo chemical alteration by various bodily systems to create compounds that are more easily excreted from the body. These chemical alterations occur primarily in the liver and are known as biotransformations.

Enzyme induction- some drugs can induce or stimulate production of the enzymes to increase metabolism (decrease amount of drug circulating in the body)

Enzyme inhibition drugs inhibit the production of CYP enzymes and decrease drug metabolism.

CYP450 enzymes- found in lipophilic ER of liver

Factors that affect it: age, genetics, gender, diet, environment, and disease state.

Answer 19

Biotransformation

Question 20

Mechanism of action

Answer 20

In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targets to which the drug binds, such as an enzyme or receptor.

Drug-receptor binding is reversible, selective (affinity), and graded.

Question 21

Affinity

Answer 21

A measure of how a drug binds to a receptor. Drug-receptor binding is selective.

Question 22

Agonist

Answer 22

Binds to a receptor site and produces a result

Question 23

Antagonist

Answer 23

Binds the receptor site and blocks an activity

Question 24

Passive diffusion

Answer 24

Molecules can move from one side of a barrier to the other without using energy. Move down a concentration gradient from an area of high concentration to low concentration solubility of drug must match absorption site (lipophilic). Has better outcome if drug molecule is non-ionized and in same pH.

Question 25

Active transport

Answer 25

Requires energy. Protein membranes of the cell can act as carrier membranes. Works if the solubility doesn’t match. But must share molecular similarities.

Question 26

Bioavailability

Answer 26

The fraction of the drug that reaches the systemic circulation.
Dependent on solubility, chemical structure, size, polarity, and presystemic biotransformation.

Question 27

First pass metabolism

Answer 27

How much of a drug is available after the first pass through absorption, usually in the liver.

When taken orally, some of it will pass through the hepatic circulation through the portal vein. Sometimes it is cleared by the liver before it ever reaches the systemic circulation.

Have to give a higher PO dose than IV because it has a higher first-pass metabolism.

Question 28

Absorption

Answer 28

First step in pharmacokinetics. Getting into the body. Dependent on first-pass metabolism, food, surface area, and drug size.
Affected by solubility, chemical structure, polarity, route, site, bioavailability, peak blood flow,

Question 29

Distribution

Answer 29

The 2nd step in pharmacokinetics. After absorption, it is transported to its site of action. Drugs bind to proteins (usually albumin) in the circulatory system. Highly bound drugs (to protein) are less available for action. Low binding drugs have higher distribution.

Less available protein, more free drug and higher chance for toxicity.

Barriers: blood-brain barrier and placental barrier

Question 30

Hypoalbuminemia

Answer 30

Albumin is the protein that most drugs bind to. If not enough protein, there are fewer binding sites, and there is more free drug, increasing toxicity.

Question 31

Metabolism/ Biotransformation

Answer 31

3rd step in pharmacokinetics. Drug is where it needs to be now needs to be transformed. This is the process of chemically changing a drug to a different compound called a metabolite. Want to increase water solubility and decrease lipid solubility.
Affected by age, genetics, gender, diet, disease states.

Question 32

CYP450 enzymes

Answer 32

Found in the lipophilic ER membranes of the liver. They are involved in the biotransformation of drugs in the metabolism phase.
Enzyme Induction and Enzyme Inhibition

Question 33

Elimination

Answer 33

4th phase of pharmacokinetics. The excretion and their transport outside the body. A drug is removed from tissues and circulation.

Renal excretion most common. Needs to be water-soluble. Removes drug that is unbound and free in plasma. Glomelular in the filtration.

Biliary excretion- transported by liver cells from blood to bike then enter GI tract and excreted through feces.

Question 34

Half-Life

Answer 34

The amount of time over which the drug concentration in the plasma decreases to 1/2 of the original value. Ultimately determines how often a drug is administered. Takes 4-5 half-lives to reach steady state concentrations during continuous dosing of a drug.

Question 35

Enteral absorption

Answer 35

Oral route of administration. Non-ionized drugs diffuse passively down a concentration gradient for the higher Concentration (GI tract) to a lower concentration (blood)

Question 36

Biotransformation

Answer 36

Most drugs undergo chemical alteration by various bodily systems to create compounds that are more easily excreted from the body. These chemical alterations occur primarily in the liver and are known as biotransformations.

Enzyme induction- some drugs can induce or stimulate production of the enzymes to increase metabolism (decrease amount of drug circulating in the body)

Enzyme inhibition drugs inhibit the production of CYP enzymes and decrease drug metabolism.

CYP450 enzymes- found in lipophilic ER of liver

Factors that affect it: age, genetics, gender, diet, environment, and disease state.