Drug Effects

Question 1

Binding capacity of drug to receptor

Answer 1

Affinity

Question 2

Factors influencing affinity

Answer 2

Chemical Bonding
Conformation
Stereochemistry

Question 3

Ability to generate a series of biochemical events leading to an effect/ biological changes, pharmacological response, efficacy

Answer 3

Intrinsic Activity

Question 4

Types of Ligands

Answer 4

Agonist
Antagonist
Inverse Agonist

Question 5

Mimics the activity of an endogenous compounds

Answer 5

Agonist

Question 6

Agonist

Answer 6

Has affinity and intrinsic activity

Question 7

Covalent Bond

Answer 7

• Strongest Bond in drug-receptor interactions
• Ligand and receptor share pair of electrons
• Irereversible affinity
• Destroyed via endocytosis
• Strength: 50 - 150 kcal

Question 8

Ionic Bond / Electrostatic Bond

Answer 8

• Two ions of opposite charge are attracted to each other
• Reversible affinity
• Strength: 5 - 10 kcal

Question 9

Hydrogen Bond

Answer 9

• Hydrogen linked via covalent bond to a strongly electronegative atom
• Reversible binding
• Strength: 2 - 5 kcal/mol

Question 10

Hydrophobic Interactions

Answer 10

Interaction between nonpolar organic molecules
aka: London Force

Question 11

The critical portion of the structure of the drug that binds to receptor; conformational change

Answer 11

Pharmacophore

Question 12

The enzyme active site is able to accept only specific type of substrate; Rigid active site

Answer 12

Lock and Key Theory / Fischer Theory

Question 13

Conformational change occurs in the receptor allowing binding

Answer 13

Induced-fit Theory / Koshland Theory

Question 14

Governed by Law of Mass Action, inc. no. of receptor occupied = increase intensity of effect

Answer 14

Occupancy Theory

Question 15

All receptors need not to be occupied for a maximal effect

Answer 15

Modified occupancy Theory
Ariens and Stephenson

Question 16

Occurs when 100% effect is achieved even if receptors are not fully occupied

Answer 16

Spare receptor

Question 17

Maximum pharmacologic effect can be obtained if all the receptor occupied

Answer 17

Clark’s Hypothesis

Question 18

The intensity of response depends on the number of encounters of drug with receptos

Answer 18

Rate Theory

Hypothesized by Paton

Question 19

Combination of induced fit and rate theory

Answer 19

Macromolecular Pertubation Theory

Question 20

Receptors are always in a dynamic equilibrium between active form and inactive form

Answer 20

Activation-Aggregation Theory

Question 21

Agonists and Inverse agonist have selective binding affinity for the pre-existing resting and active states

Answer 21

Two-state Model of Receptor Activation

Question 22

Enantiomer

Answer 22

• Nonsuperimposable Mirror Images
• Same physicochemocal properties

Question 23

Diastereomer

Answer 23

• 2 chiral centers
• Not Mirror image
• Not superimposable
• Different physicochemical properties