Pharmacology and Therapeutics Lecture #2
PHARMACODYNAMICS
UPDATED FOR 2025-2026
OUTLINE: the response)
I. PHARMACODYANMICS
MODIFIABLE when they bind a drug
II. RECEPTORS
III. EFFECTORS molecule
IV. GRADED DOSE-RESPONSE RELATIONSHIPS
A. Maximal efficacy
B. Potency
V. GRADED DOSE-BINDING RELATIONS &
BINDING AFFINITY
VI. QUANTAL DOSE-RESPONSE RELATIONSHIPS
VII. POTENCY
VIII. SPARE RECEPTORS
IX. INERT BINDING SITES
X. AGONISTS & PARTIAL AGONISTS
XI. ANTAGONISTS
XII. THERAPEUTIC INDEX
XIII. THERAPEUTIC WINDOW
XIV. SIGNALING MECHANISMS
XV. RECEPTOR REGULATION
XVI. References
RECEPTORS
specific molecules in a biologic system with
PHARMACODYNAMICS which drugs interact to produce changes in
What the DRUG does TO the BODY whereas the function of the system
pharmacokinetics refers to what the body does to selective, ligand-binding macromolecules
the drug mediating effects of endogenous
Refers to the biochemical, physiological, substances
molecular effects of drug thru their actions on characteristic:
receptors providing that the receptor is
SATURABLE (meaning if the
complementary to the shape of the drug
deals with the effects of drugs on biologic receptors are saturated, no matter
systems especially on its action on receptors how much you increase the dose of
the drug, its effect would no longer
be increased)
SELECTIVE in their ligand-binding
characteristics (in order to maximize
STUDYPOOL NOTEBANK
Page 1 of
, Pharmacology and Therapeutics Lecture #2
PHARMACODYNAMICS
most are proteins but those enzymes that are
affected by drugs are considered receptors
The RECEPTOR SITE (also known as the
RECOGNITION SITE) for a drug is the
specific binding region of the receptor
macromolecule and has a relatively high and
selective affinity for the drug
The interaction of a drug with its receptor is
the fundamental event that initiates the action
of the drug.
molecules that translate the drug-receptor EFFECTORS
interaction into a change in cellular activity
examples:
1. Adenylyl cyclase: cAMP Pathway
- cAMP serves as secondary
messenger
- actions of cAMP:
a. mobilization of stored energy
b. conservation of water by the
kidney
c. calcium homeostasis
d. increased rate & contractile rate of
the heart
e. regulates the production of
adrenal & sex steroids
f. relaxation of smooth muscle
2. Tyrosine kinase effector enzyme
- kinases are responsible for
phosphorylation of proteins
- it incorporates both drug-binding site
& effector mechanism
3. Sodium-potassium channel
STUDYPOOL NOTEBANK
Page 2 of
PHARMACODYNAMICS
UPDATED FOR 2025-2026
OUTLINE: the response)
I. PHARMACODYANMICS
MODIFIABLE when they bind a drug
II. RECEPTORS
III. EFFECTORS molecule
IV. GRADED DOSE-RESPONSE RELATIONSHIPS
A. Maximal efficacy
B. Potency
V. GRADED DOSE-BINDING RELATIONS &
BINDING AFFINITY
VI. QUANTAL DOSE-RESPONSE RELATIONSHIPS
VII. POTENCY
VIII. SPARE RECEPTORS
IX. INERT BINDING SITES
X. AGONISTS & PARTIAL AGONISTS
XI. ANTAGONISTS
XII. THERAPEUTIC INDEX
XIII. THERAPEUTIC WINDOW
XIV. SIGNALING MECHANISMS
XV. RECEPTOR REGULATION
XVI. References
RECEPTORS
specific molecules in a biologic system with
PHARMACODYNAMICS which drugs interact to produce changes in
What the DRUG does TO the BODY whereas the function of the system
pharmacokinetics refers to what the body does to selective, ligand-binding macromolecules
the drug mediating effects of endogenous
Refers to the biochemical, physiological, substances
molecular effects of drug thru their actions on characteristic:
receptors providing that the receptor is
SATURABLE (meaning if the
complementary to the shape of the drug
deals with the effects of drugs on biologic receptors are saturated, no matter
systems especially on its action on receptors how much you increase the dose of
the drug, its effect would no longer
be increased)
SELECTIVE in their ligand-binding
characteristics (in order to maximize
STUDYPOOL NOTEBANK
Page 1 of
, Pharmacology and Therapeutics Lecture #2
PHARMACODYNAMICS
most are proteins but those enzymes that are
affected by drugs are considered receptors
The RECEPTOR SITE (also known as the
RECOGNITION SITE) for a drug is the
specific binding region of the receptor
macromolecule and has a relatively high and
selective affinity for the drug
The interaction of a drug with its receptor is
the fundamental event that initiates the action
of the drug.
molecules that translate the drug-receptor EFFECTORS
interaction into a change in cellular activity
examples:
1. Adenylyl cyclase: cAMP Pathway
- cAMP serves as secondary
messenger
- actions of cAMP:
a. mobilization of stored energy
b. conservation of water by the
kidney
c. calcium homeostasis
d. increased rate & contractile rate of
the heart
e. regulates the production of
adrenal & sex steroids
f. relaxation of smooth muscle
2. Tyrosine kinase effector enzyme
- kinases are responsible for
phosphorylation of proteins
- it incorporates both drug-binding site
& effector mechanism
3. Sodium-potassium channel
STUDYPOOL NOTEBANK
Page 2 of
