Dose Response Relationships Receptor Theory

Question 1

According to DRRRT What creates a the physiological response of a drug?

Answer 1

Drug Binds receptor–> Forms Drug + Receptor complex –> Initiates response

Question 2

What is the law of Mass action?

Answer 2

Binding occurs when the ligand and receptor collide

Question 3

What is the strength, or concentration, of drug needed to produce an effect? How is it measured?

Answer 3

Potency

ED50: The dose which will produce an effect half of the maximal response

Question 4

What three factors influence drug binding?

Answer 4

Receptors
Concentration of drugs
Affinity

Question 5

Ceiling effect

Answer 5

The limit of some drugs to produce an effect; above produces no further effect. (Ex. Amoxacillin X14 days for Strep)

Question 6

What is Onset of Action in Time plasma curve?

Answer 6

The time from administration which you see the first observable effects

Question 7

What is termination in time plasma curve?

Answer 7

when plasma drug concentration falls below therapeutic range

Question 8

Three types of agonist

Answer 8

Full Agonist

Partial Agonist

Inverse Agonist

Question 9

How does a competitive antagonist affect the ED50.

Answer 9

Higher dose needed to produce response –> INC ED50

Question 10

How does Competitive antagonist shift curve?

Answer 10

Shifts curve to the right

Question 11

How do noncompetitive antagonists affect drug response curves?

Answer 11

Reduce Efficacy (Shift Downward)\

INC in drug WILL NOT produce ore effects

Question 12

What is TD50? LD50?

Answer 12

Toxic Dose 50: Amount in which it produce a toxic effect in 50% of population

Lethal Dose 50: Amount which well have lethal effect in 50% of population

Question 13

What is therapeutic Index?

Answer 13

TD50/ED50

Question 14

What are common drugs which have a low TI?

Answer 14

(Warning! These Drugs are Lethal)

Warfarin
Theophylline
Digoxin
Lithium

***Erthromyocin + Theophylline

Question 15

What are the types of transmembrane receptor signals?

Answer 15

1. lipid soluble chemical crosses the membrane and binds intracellularly
2. Drug binds extracellular receptor –> Enzymatic activity of intracellular domain
3. Drug binds EC protein and activates Tyrosine Kinase
4. Ion Channel linked
5. G Protein linked

Question 16

ID type of signal mechanism

Cholinergic
Dexamethasone
Insulin
Alpha Adrenergics

Answer 16

Cholinergic: Ion-linked

Dexamethasone: Intracellular

Insulin: Enzyme-linked

Alpha-adrenergic: G protein-coupled

Question 17

Types of intracellular receptors and examples

Answer 17

Transcription Factors: Dexamethasone
Intracellular enzymes: NSAIDS
Structural proteins: Colchicine
Nucleic Acids: Rubicin
Signal transduction molecules: mTOR

Question 18

What is the primary use and advantage of GABAergic drugs?

Answer 18

GABA receptors allow chlorine to pass into cell and cause a decrease in action potentials

Question 19

What is the primary use/advantage of nicotinic receptors?

Answer 19

Most rapid response time

Question 20

What two categories use Tyrosine Kinase receptors?

Answer 20

Insulin

Monoclonal antibodies (-imab)

Question 21

Tachyphylaxis

Answer 21

Decreased ability of receptor to respond to any drug.