answers provided
Pharmacology ✅✅the study of drugs
-Toxicology (study of environmental toxins)
-therapeutics: 2 subtypes--> (use a drug to treat a disease)
1. pharmacodynamics (what a drug does to the body)
2. pharmacokinetics (what the body does to a drug, absorb, distribute etc)
what is a drug ✅✅any chemical that changes the processes of living
Drug Nomenclature ✅✅Chemical name: N-Acetyl-p-aminophenol (development
stage)
Generic Name: Acetominophen (easier to pronounce and remember) *only 1 generic
name. They all have the same suffix.
Trade name: Tylenol (can be numerous trade names)
Drug Resources ✅✅1. physicians desk reference (PDR)
2. Nursing drug guides (mosby's' et al.)
3. Online resources (epocrates.com)
What is a receptor? 5 components ✅✅1. some component on or inside a cell that
substances can bind
2. Most drugs and endogenous substances bind receptors
3. Most protein based
4. Lock and key (structurally match up to receptor)
5. Receptor Subtypes (ex: ACH-nicotinic receptor: recognizes both autonomic ganglion
and skeletal muscle, but can make one that only recognizes on area)
Types of Receptors ✅✅1. Receptors located on the cell surface
2. Intracellular Receptors
-Cytosolic receptors
-Nuclear receptors
,Why have receptors on the cell surface? ✅✅Majority of hormones are not have able
to cross the membrane through diffusion, so they have to bind to a receptor on the
surface to get into the cell.
They are not lipid soluble.
most hormones and neurostransmitters are lipid INSOLUBLE, so they need receptors to
bring them into the cell.
Receptors on the cell surface
Communication of hormones and receptors. ✅✅1. Receptors are linked to ion
channels. They control the opening of it. (Ex: acetylcholine is able to get Na+ into the
cell by initiating opening of ion channels when it binds)
2. receptors linked to enzymes (ex: insulin or GH, bind to receptor on surface and
causes the enzymatic portion to produce changes within the cell. *Picture ^)
3. Receptors linked to second messengers
(Both use G proteins: Adenylate Cyclase System, IP3 system)
Second Messenger System
Adenylate Cyclase steps ✅✅1. hormone binds to the specific receptor (1st
messenger) *The receptor must be COUPLED to the G protein to work.
2. Causes GTP to bind to protien
3. Causes G protein to move away from receptor through the membrane until it
encounters an enzyme
4. the enzyme is adylte. cyclase
5. ad cly. takesATP and convert it to cyclic ATP
6 .CYClic ATP is our second messenger.
7. Cyclic ATP activates an enzyme and triggers responses of the target cell.
Second messenger system
Phospholipase C Mechanism (IP3 system) Steps ✅✅1. hormone binds to receptor
2. receptor coupled to g protein
3. G protein moves away from receptor into the membrane
4. moves through membrane and encounters enzyme phospholipase C
5. Phospholipase C causes the production of 2 products (BAG and IP3)
6. It allows the signals to become amplified.
Ex: Every step of the way the response gets bigger. 2 --> 4 --> 8 -->16
Intracellular Receptors (2)
, LIPID SOLUBLE substances ✅✅1. Cytosolic (cytoplasm) ex: thyroid hormone
2. Nuclear (goes into nucleus)
Non receptor mechanisms ✅✅- Nitrates- reduced to NO, bind guanylate cyclase
Ex: vasodilators
-Some chemotherapeutic agents become incorporated into cellular components and
block metabolic reactions
agonist
antagonist ✅✅ag: drug that binds a receptor and produces a biochemical response
Ant: binds the receptor but doesn't produce a biochemical response. "it's a blank" No
second messenger is produced.
*So why have it? tumor causing too much epinephrine binding, so antagonist drug
competes with epinephrine for that receptor and blocks its ability to bind and cause the
heart to contract too much.
Affinity: high vs low.
Specificity= selectivity (dose-dependent)
* You want highly selective/specific drugs. So you don't produce side-affects ✅✅A:
attraction between a drug and a receptor
High affinity: drug will bind, even when the drug is in extremely low concentration
Low affinity: won't bind drug until there is a high concentration of it.
S: How specific the drug is for a particular type of receptor.
Drugs that are highly selective, ONLY bind to that one receptor.
As the dose is increased, it may become less and less selective.
*this causes side-affects to go up.
Efficacy
Intrinsic Activity ~ efficacy ✅✅E: Does the drug to what it was intended. Effectiveness
of the drug.
*more important than potency
IA: More effective response even by stimulating it just a little bit.
Potency
Tolerance