Pharmacodynamics Flashcards
A substance that has physiological effect when ingested or introduced into the body
Drugs
Drugs is used to
Treat
Cure
Mitigate
Prevent
Diagnose
Divisions of Pharmacology
a. Pharmacodynamics
b. Pharmacokinetics
c. Pharmacotherapeutics
Study of selective biologic activity of drugs and of substances that interact w/ living systems through chemical processes, especially by binding to regulatory molecules & activating or inhibiting normal processes
Pharmacology
What the drug does to the body
Pharmacodynamics
Branch of pharmacology that deals with drug effect and drug actions
Pharmacodynamics
Classification of Drugs
- Functional Modifiers
- Replenishers
- Diagnostics
- Chemotherapeutics
Alters certain physiologic functions & activities of body cells
Functional modifiers
Supplement the existing endogenous compound that are deficient or lackin in concentration
Replenishers
Diagnosis or confirmation of absence or presence of certain diseases
Diagnostics
Agents used to kill/ inhibit growth of cells considered as foreign to the body
Chemotherapeutics
Sensation of pain (analgesics, anesthetics)
Tachycardia (beta-blockers)
Morphine - narcotic analgesic; pain perception
Bevacizumab
Functional Modifiers
DM type 1 (Insulin)
Pernicous Anemia (Vit B12)
Diarrhea (ORS)
Replenishers
DM type 1 (Insulin)
Pernicous Anemia (Vit B12)
Diarrhea (ORS)
Replenishers
Edrophonium (Tensilon®)
Barium sulfate
Metacholine Test
Dobutamine/ Dipyridamole
Diagnostics
Anti-infectives, Anti-microbials
Anti-neoplastics
Chemotherapeutics Agents
Anti-infectives, Anti-microbials
Anti-neoplastics
Chemotherapeutics Agents
Protein molecules whch bind a chemical signaling molecule and undergoars conformational change which activates signaling pathway
Receptors
Receptor Types
Type I or Ionotropic Receptors
Type II or Metabotropic Receptors
Type III or Enzyme-linked receptors
Type IV or Nuclear Receptors / Gene Transcription-linked
Receptor
Type I Ligand-gated Ion Channels
Ion Channel linked receptors
Controls movement of ions in & out the cell
Effect seen in milliseconds
Location: Cell Membrane
Example of Type I or Ionotropic Receptors!
- Nicotinic receptors (ligand-gated Na channel)
o Inhibited by NMBs & ganglionic blockers - GABAA receptors (CI channel)
o Inhibitory NT
o Facilitates influx of CI ions resulting to hyperpolarization
o Stimulated by benzodiazepines, barbiturates
Barbiturates and benzodiazepenes enhances
Type II or G protein-coupled receptor
G-protein linked, coupled receptors
Largest Family
7-transmembrane spanning receptors
increase or decrease of secondary
messengers
Location: cell membrane
Onset: seconds
Type III or Enzyme-linked Receptors
Phosphorylation
Stimulation of glucokinase (glycolysis)
Translocation of glucose transporters
(GLUT2, GLUT4) into the cell membrane
Tyrosine Kinase (Insulin)
Type III or Enzyme-linked Receptors!
Phosphorylation
Stimulation of glucokinase (glycolysis)
Translocation of glucose transporters
(GLUT2, GLUT4) into the cell membrane
Type IV / Gene Transcription-linked Receptor / Nuclear Receptors / Intracellular
Modulate gene transcription
Drugs must be lipophilic
Intracellular
DRUGS: sex hormones, thyroid hormones, Vit D, steroidal hormones (corticosteroids)
Location of Receptors
Type I, II, III - Cell Membrane
Type IV - Nucleus / Cytoplasm
Main Action of Receptors
Type I - Ion flux
Type II - Second Messengers
Type III - Phosphorylation
Type IV - Gene Transcription
Response / Onset Time of Receptors
Type I - Millisec
Type II - Sec
Type III - Minutes
Type IV - Hours
Examples of Receptors
Type I - GABA-A, Nicotinic
Type II - Adrenergic Receptors (Alpha, Beta)
Type III - Insulin, Platelet
Type IV - Steroid, Sex Hormones, Non-Steroid
Secondary Messengers
a. cAMP (cyclic adenosine monophosphate)
b. cGMP (cyclic guanosine monophosphate)
* aforementioned secondary messengers utilizes same signalling cascades
* intestinal mucosa & blood vessels
c. IP3 (inositol triphosphate)
d. DAG (diacylglycerol)
Types of G-proteins
a. Gs - stimulates adenylyl cyaclase (AC)
* ex. Beta-receptors
* stimulators: Epi, NE
* Blockers: Beta-blockers (-olols)
b. Gi - inhibits adenylyl cyclase (decrease
cAMP)
* ex. Pre-synaptic Alpha2 receptors!
* stimulators: Clonidine, Methyldopa,
Guanfacine, Guanabenz
* ex M2 receptors
c. Gq - stimulates Phospholipase C (PLC)
* PLC stimulates the formation of IP3 & DAG from PIP2. (increased intracellular Calcium ions =
contraction)
* ex. Alpha1
* blockers: -zosin (Alprazosin)
* ex. M1, M3
* ex. Post-aynaptic Alpha2
Adrenergic Receptors
α1: Gq (+) Adenylyl cyclase = DAG, IP3
α2: Gi (-) Adenylyl cyclase = ↓ cAMP
β3: Gs (+) Adenylyl cyclase = ↑ cAMP
β4: Gs (+) Adenylyl cyclase = ↑ cAMP
