Pharmacology

Question 1

Briefly describe the three targets of drug action.

Answer 1

1. Mimetic of endogenous ligand
   ▪ Same activity as endogenous ligand
2. Blockers
   ▪ Prevent transfer of molecules or binding of endogenous
   ligand
3. Allosteric modulators
   ▪ Influences activity of endogenous ligand either
   positively or negatively

Question 2

Therapeutic index (TI)

Answer 2

Measure of drug’s safety as garnered from animal model

Question 3

Affinity

Answer 3

Ability of drug to bind to receptor
Higher affinity allows for greater occupation
Affinity determined by forces at play

Question 4

Occupation

Answer 4

Binding of drug to a receptor
Controlled by affinity.

Question 5

Activation

Answer 5

Eliciting a cellular response
Controlled by efficacy

Question 6

Efficacy/ Intrinsic activity

Answer 6

Tendency to activate the receptor
based on drug-receptor complexes

Question 7

Selectivity

Answer 7

Ability to bind only specific receptors or drug targets

Question 8

Cross reactivity

Answer 8

Drug acts as ligand to numerous drug targets
▪ Affinity and efficacy depends on the receptor type
▪ Produces differential effects if selectivity is lost, most often unwanted effects.

Question 9

what are the two pathways for prostaglandin synthesis?
what are the products of each pathway?

Answer 9

Cyclooxygenase pathway
Thromboxane
prostaglandins

Lipoxygenase pathway
Leukotrienes

Question 10

What is the difference between a drug and a medicine?

Answer 10

A drug is a chemical substance of a know structure that produces biological effects within living organisms when administered.

A drug is the chemical preparation of an agent(s) administered with intent to illicit a therapeutic effect.

Question 11

Explain topical, transdermal and subcutaneous routes of administration.

Answer 11

Topical - Applied to the surface of the skin and is not absorbed into the skin. Effects are more localized.

Transdermal applied to the skin and is absorbed into the skin, to reach the blood vessels to allow for systemic effects.

Subcutaneous is an injectable route of administration (at 45 degree angle). It allows for the diffusion of the drug into the subcutaneous tissue , the deepest layer of your skin. It’s made up mostly of fat cells and connective tissue. It also has a localized effect with rapid distribution.

Question 12

Absorption

Answer 12

movement of the drug from the site of administration to the
blood circulation

Question 13

Distribution

Answer 13

diffusion or transport of drug from intravascular space to
extravascular space

Question 14

Metabolism

Answer 14

chemical conversion or transformation of drugs into
compounds for easier elimination

Question 15

Excretion

Answer 15

elimination of unchanged drug or metabolite from body via
excretory system

Question 16

Half-life

Answer 16

The time it takes for the plasms concentration to decrease by half.

Question 17

Elimination rate

Answer 17

Time taken for drug to be eliminated from body.

Question 18

Steady state

Answer 18

Steady state achieved when rate of drug absorption equals
drug elimination, and Cp plateaus

Question 19

Efficacy

Answer 19

The max effect a drug is capable of producing based on it therapeutic goal.

y axis

Question 20

Effective dose (ED)

Answer 20

Minimum drug amount required to achieve max therapeutic effect.

Question 21

ED50

Answer 21

The dose required to produce 50% of the max possible response.

Question 22

potency

Answer 22

strength of drug at particular dose
the amount of a drug required to produce 50% of the max effect the drug can achieve.

x axis

Question 23

Agonist

Answer 23

Ligands for receptor that result in its activation, thus possesses
affinity and efficacy