3- Agonist-Antagonist

a. affinity

1. The capacity of the drug to bind to its receptor

   a. affinity

   b. intrinsic activity

   c. constitutive activity

   d. efficacy

a. chemical antagonism

2. What type of antagonism is present between heparin & protamine sulfate

   a. chemical antagonism

   b. physiologic antagonism

   c. pharmacologic antagonism

   d. mechanical antagonism

d. AOTA

3. Two drugs acting of the same receptor giving opposite effects

   a. Competitive antagonism

   b. Non- competitive antagonism

   c. pharmacologic antagonism

   d. AOTA

d. drug & receptor complexation

4. Intrinsic activity may refer to the ff, except:

   a. Efficacy

   b. Biologic activity

   c. pharmacologic response

   d. drug & receptor complexation

a. Physiologic antagonist

5. What type of antagonism is present when two drugs produce opposite effects after activating different receptors?

   a. Physiologic antagonist

   b. Pharmacologic antagonist

   c. Chemical antagonist

   d. Irreversible antagonist

c. Chemical antagonist

6. Heparin + Warfarin

   a. Competitive antagonist

   b. Non-competitive antagonist

   c. Chemical antagonist

   d. Mechanical antagonist

a. agonist

7. it mimics the action of an endogenous compound.

   a. agonist

   b. antagonist

   c. inverse agonist

   d. NOTA

b. constitutive activity

8. The activity of a receptor in the absence of a ligand

   a. bioactivity

   b. constitutive activity

   c. pharmacologic activity

   d. efficacy

b. partial agonist

9. A drug that provides submaximal effect

   a. Full agonist

   b. partial agonist

   c. inverse agonist

   d. antagonist

Agonist

Mimic the action of endogenous compounds

Antagonist

Block the effect of agonist

Full Agonist

100% response

MORPHINE, ISOPROTERENOL

examples of Full Agonist

MORPHINE

a full agonist that mimics endorphin

ISOPROTERENOL

a full agonist that mimics NE

Partial Agonist

• <100% response (submaximal effect)

• use for withdrawal symptoms

BUPRENORPHINE, VARENICLINE

Examples of Partial Agonist

BUPRENORPHINE

a partial agonist drug that decrease the cravings for opioids

VARENICLINE

a partial agonist drug that is smoking deterrant

Antagonist

Full agonist + partial agonist →

Inverse Agonist

opposite effect (Paradoxical effect)

Beta-carbolines activate GABA-a

example of Inverse Agonist

anti-convulsant

expected response for Beta-carbolines activating GABA-A:

pro-convulsant

actual response for Beta-carbolines activating GABA-A:

TRUE

TRUE OR FALSE

Inverse agonists are not antagonists

Pharmacological Antagonist

• 2 drugs binding to the same receptor

• Result: Opposite effect

Reversible

• Aka Equilibrium Competitive Antagonist

• Ionic bond

• Surmount

• Ex: Atropine + Acetylchoine

Atropine + Acetylchoine

examples of reversible competitive antagonists

Irreversible

• Aka Non-Equilibrium

• Covalent bond

• Non-surmountable

• Ex: PPI + Hyperacidity

Non-Competitive Antagonist

• Allosteric Antagonist

• Irreversible

• Non-surmountable

Uncompetitive Antagonists

• agonists activate the receptor first then antagonist binds to allosteric

• REVERSIBLE

Physiological Antagonist: Functional Antagonist

• Two drugs acting on independent or independent receptors

• Same activation but different MOA

• For Anaphylaxis: H1 receptor + Epinephrine

• Acetylcholine + Norephenipherine

Physiological Antagonist examples:

Functional Antagonist

Physiological Antagonist is also known as

Chemical Antagonist

• NO RECEPTOR

• Direct interaction between agonist & antagonis

• Change the chemical nature

• Prevent binding of agonist to the target tissue

Goals of Chemical Antagonist

Neutralization, Chelation

MOA of Chemical Antagonist:

• BAL + Pb (or As)

• Antacid + Hyperacidity

• Protamine Sulfare + Heparin

Examples of Chemical Antagonist