pharmacology

Question 1

what is pharmacology the study of?

Answer 1

Actions
Mechanisms
Uses
Adverse effects of drugs

Question 2

What 2 disciplines are pharmacology divided into?

Answer 2

pharmacodynamics (PD) and pharmacokinetics (PK)

Question 3

What is the definition of a drug?

Answer 3

Natural/ semi-synthetic or synthetic substance that alters the physiological state of a living organism/ system.

Question 4

What are the 7 classifications of drugs?

Answer 4

1. Chemical structure
2. Source
3. Target organ/ site of action
4. Mode of action
5. Therapeutic uses
6. Physiological system
7. Physical effects

Question 5

What are the 3 names that drugs are given?

Answer 5

Chemical, non-proprietary (generic) and propriety (brand)

Question 6

what id the definition of pharmacodynamics?

Answer 6

Pharmacodynamics is studying the effects of a drug on various systems in the body.

Question 7

What does Pharmacodynamics look at?

Answer 7

It looks at:
how the drug binds to the target site and initiates changes in various systems to change their physiological state

It also explains why some drugs maybe more potent than others or why different doses maybe needed

Question 8

Drug binds to receptors to initiate changes in cells leading to therapeutic/ adverse effects/

what can drugs be?

Answer 8

Agonist
Partial agonist
Antagonist: competitive or irreversible (non-competitive)

Question 9

What is the definition of Pharmacokinetics?

Answer 9

Pharmacokinetics is a fundamental scientific discipline that underpins the administration of drugs

Question 10

What does Pharmacokinetics follow?

Answer 10

It follows a drug from the moment that it is
administered up to the point at which it is completely
eliminated from the body

Question 11

What is a short definition of pharmacokinetics and pharmacodynamics?

Answer 11

Pharmacokinetics - what the body does to the drug/ substance

Pharmacodynamics - what the drug/ substance does to the body

Question 12

What are the 4 main principles of Pharmacokinetics?

Answer 12

Absorption
Distribution
Metabolism
Elimination

Question 13

What does absorption refer to?

Answer 13

Refers to the amount of drug
in general circulation

bioavailability

Question 14

what is bioavailability?

Answer 14

The fraction of drug available to produce an effect
Amount of drug in general circulation
F = ——————————————–
Amount of drug administered

Question 15

What are 3 mechanisms of drug transfer?

Answer 15

Passive diffusion
Active transport
Facilitated transport

Question 16

what are 3 basic concepts of Pharmacokinetics?

Answer 16

Drug transfer

Drug properties

Effect of pH

Question 17

What makes up drug formulations?

Answer 17

Solid/ semisolid
Liquid: suspension, solution
Polymer

Question 18

What makes up Drug chemistry?

Answer 18

Molecular size and shape
State of ionization
Lipid – water partition coefficient

Question 19

what influences the degree of dissociation?

Answer 19

pH of solution
pKa of the drug (dissociation constant)

Question 20

What happens when ionized drugs become trapped in certain areas?

Answer 20

They cannot diffuse anymore thus reducing the amount of drug available to produce an effect

Question 21

What is the clinical importance of absorption?

Answer 21

different routes of administration can maximize drug bioavailability

Question 22

What effects do changes in bioavailability have on drugs?

Answer 22

Loss of drug effectiveness

drug toxicity

Question 23

what are common routes of administration?

Answer 23

Enteral administration
- oral – po
- rectal
- sublingual, buccal

Parenteral administration - routes other than the digestive tract
- intravenous – iv (bioavailability 100%)
- intramuscular – im
- Subcutaneous – sc
- transdermal
- inhalation
- topical
- intrathecal (CSF)

Question 24

What is used as an index of drug concentration in tissue?

Answer 24

Plasma concentration

Question 25

what is the Volume of distribution?

Answer 25

Theoretical volume (in L) into which a drug dissolves to produce the plasma concentration observed at steady state

    Amount of drug given = Dose Vd = -----------------------------------------------         Steady state plasma concentration = Cpl

Question 26

What is the clinical importance of volume distribution?

Answer 26

changes in VD influence plasma concentration of drug and dose may need adjusting

Question 27

What is lipophilic?

Answer 27

Lipid soluble

Question 28

Which molecules can be eliminated from the body?

Answer 28

only water soluble molecules

Question 29

Where is a major site of metabolism?

Answer 29

The liver

but can also occur in the kidneys or lungs

Question 30

What is metabolism influenced by?

Answer 30

Interaction with other drugs/ supplements
Ageing
Diseases (mostly important liver disease)
Genetic polymorphism

Question 31

What are common methods of drug elimination?

Answer 31

Renal
Pulmonary
Biliary
Sweat, tears
Breast milk

only hydrophilic molecules can be excreted

Question 32

What are the 2 types of time dependent patterns of drug elimination?

Answer 32

first order and zero order kinetics

Question 33

What is first order kinetics?

Answer 33

Constant fraction of drug eliminated per time.
rate of drug elimination proportional to drug plasma concentration.

graph - curved

Question 34

What is zero order kinetics?

Answer 34

constant amount of drug eliminated per time

Rate of drug elimination independent of drug plasma concentration.

Graph: straight line

Question 35

What is the clinical importance of 1st order kinetics?

Answer 35

Time to eliminate drug independent of dose

Increasing dose or frequency of administration produces predictable rises in plasma concentration

Majority of drugs use first order kinetics

Question 36

What is the clinical importance of zero order kinetics?

Answer 36

Time to eliminate drug dependent of dose

Increasing dose or frequency of administration produces unpredictable rises in plasma concentration

Makes drug administration complicated

Question 37

what are Important parameters of 1st order kinetics?

Answer 37

1. Elimination rate constant ke: describes the fraction of drug eliminated per unit time
2. Half-life: interval of time to reduce the plasma concentration by one half