Intro class

Question 1

True/False? The definition of a Drug: ANY substance with an effect on living cells

Answer 1

True

Question 2

Define pharmacology

Answer 2

All aspects of drugs and their interactions with living organisms

Question 3

What are the three main (clinical) uses of drugs?

Answer 3

Therapy (treating conditions)
Diagnosis
Prophylaxis of disease

Question 4

What is the key competency of therapy?

Answer 4

There must be a balance between benefit and risk

Question 5

What properties of a drug must we know to use it properly? (4 things)

Answer 5

Pharamcodynamics
Pharmacokinetics
Efficacy
Safety

Question 6

List the 5 types of chemical bonds in order of decreasing strength

Answer 6

Covalent bonds
Ionic bonds
Hydrogen bonds
Hydrophobic interactions
Van der Waals Forces

Question 7

Name 6 different molecular drug targets

Answer 7

Receptors
Enzymes
Carrier molecules (symport/antiport)
Ion channels (ligand- or voltage-gated)
Idiosyncratic targets (metal ions, surfactant proteins, gastrointestinal contents)
Nucleic acids

Question 8

True/False? A dose-response curve is nearly linear when concentration is plotted logarithmically.

Answer 8

True

Question 9

True/False? Positive allosteric modulators (PAM) and Negative allosteric modulators act on the allosteric site to create or end a response.

Answer 9

False, they Modulate response

Question 10

Describe the Therapeutic Index and two ways to calculate it

Answer 10

The relative concentration difference between therapy and toxic effects

1) TI = LD50/ED50
2) TI = TD01/ED99

Question 11

True/False? A higher Therapeutic index implies an increased margin of safety

Answer 11

True

Question 12

What is the main point of that complicated flowchart demonstrating the factors influencing drug concentrations?

Answer 12

Multiple compartments = unequal distribution

Question 13

What is the difference between an active drug and a prodrug in terms of 1. Activity? 2. Metabolism?

Answer 13

1. Active drugs are active
   Prodrugs are not active
2. Active drugs are metabolised into inactive drugs
   Prodrugs are metabolised into active drugs

Question 14

Why does metabolism differ between individuals?

Answer 14

Genetic variation

Question 15

Define the MEC

Answer 15

Minimum effective concentration (can relate to a specific effect)

Question 16

Define pharmacokinetic intensity

Answer 16

The distance between the response MEC and its peak effect

Question 17

Define therapeutic windwo

Answer 17

Distance between response MEC and toxic MEC

Question 18

Describe the difference between pharmacokinetics and pharmacodynamics

Answer 18

pkinetics: How a drug gets to its target site (ADME)
pdynamics: What a drug does at its active site

Question 19

What is the equation for apparent volume of distribution?

Answer 19

Vd = Dose/C

usually Cplasma

Question 20

What is a half life?

Answer 20

The time it takes for 50% of a drug to be eliminated from the body

Question 21

How many half lives does it take for the drug to be considered “eliminated” from the body?

Answer 21

4

50 + 25 + 12.5 + 6.25 = 93.8%

Question 22

Define drug clearance

Answer 22

The amount of blood cleared of drug per unit time

Calculated by rate of drug disappearing from plasma/drug conc in plasma

Question 23

What is a drug’s maintenance dose and how is it calculated?

Answer 23

The rate and dose of which you need to keep administering to stay within the therapeutic window

Maintenance dose: target concentration x clearance
or
target conc x (elimination rate/plasma conc)

Question 24

Describe the pathway an orally administered drug takes to get into systemic circulation and note when some of that dose is lost

Answer 24

Oral dose -> GI tract -> absorption* -> portal vein -> liver** -> systemic circulation

• stomach absorption depends on pH solubility of drug
• • first pass metabolism, most of the drug extracted