basic pharmacology

Question 1

Describe Graph of Dose Response

Answer 1

drug effect / concentration curve.

Drug effect E, Emax

Question 2

Describe Graph of Receptor Binding

Answer 2

receptor bound drug/ concentration curve

Bmax

Question 3

what is Pharmacological Efficacy

Answer 3

it is about Receptors having two conformations in equilibrium. Mostly inactive receptor

Question 4

Agonist

Answer 4

If ligand alters equilibrium of receptor conformations, it is an agonist. From being Ri to being mostly Ra

Question 5

Partial agonist

Answer 5

If ligand makes a submaximal change in equilibrium, it is a partial agonist. From being Ri to being lite more Ra compared to equilibrium.

Question 6

inverse agonist

Answer 6

Ligands causing shift to inactive receptor are called “inverse agonists”

Question 7

Efficacy

Answer 7

Efficacy: ability of ligand to produce effect

Full agonist has efficacy of 1.0

Question 8

Potency

Answer 8

Potency: dose required for a specific effect

Question 9

Competitive Antagonists

Answer 9

bind to same site as agonist
•If bound, prevent agonist binding
•Excess agonist will compete off antagonist* •Therefore potency of agonist appears to be lowered

Question 10

Non-competative antagonist

Answer 10

Don’t share binding site with agonists
•Cannot be competed away by agonist
•Prevent effect upon agonist binding
•Reduce agonist Emax rather than potency
•Effect on agonist dose curve like irreversible antagonist

Question 11

Desensitisation

Answer 11

Desensitization refers to the common situation where the biological response to a drug diminishes when it is given continuously or repeatedly. It may be possible to restore the response by increasing the dose (or concentration) of the drug but, in some cases, the tissues may become completely refractory to its effec

Question 12

tachyphylaxis

Answer 12

The term tachyphylaxis is used to describe desensitization that occurs very rapidly, sometimes with the initial dose.

Question 13

Desensitisation and tachyphylaxis. descirbe the 6 points that get affected

Answer 13

• Change in receptor -phosphorylation of intracellular regions, channels and GPCRs
• Loss of receptor that can accure trough internalization, be broken down and need to senticise the system.
• Exhaistion of mediator- ex. amphetamine that depletes amine stores. need to have mediater, if it used up u dont get effect of drug
• Increased metabolic degradation of the drug -ex. barbiturates, ethanol (opposite for nitrates). drug degraded of differ enzymes. can be upp or down regulated. the enxyme can be effected
• Physiological adaptation -compensation, diuretic compound activate renin angiotensin system, increased blood pressure. ex BP regulated by many system
• Active extrusion of drugs from cells -cancer drugs. enzyme, transporters, different molecules gets upregulated to get rid of the durg