Exam 1 Study Guide Flashcards
Define pharmacology
The study of substances that interact with living systems through chemical processes
What did Paracelsus famously state? What is he known as?
“The dose makes the poison”
He is known as the father of Toxicology
Define Phamacodynamics
“Actions of the chemical on the organism”
What the drug does to the body
Define Pharmacokinetics
Absorption
Distribution
Metabolism
Excretion
What the body does to the drug
Pharmacogenomics
The relation of a person’s genetic makeup to his or her response to a specific drug
Define Agonist
A drug or endogenous substance that binds to a receptor and initiates a response (activates receptor)
Define Antagonist and give and example
Drug or endogenous substance that compete to bind with receptor sites to block or prevent agonist from accessing receptor
Can be reversible or irreversible depending on the strength of the bond
Ex: Atropine prevents the binding of acetylcholine to receptor sites
Define Allosteric site
Site of bonds that occur somewhere on the protein outside of the receptor site
Can help activate (allosteric activator) or inhibit (allosteric inhibitor)
Remember:
ALLosteric= ALL of us are outside of the OR right now
Define Orthosteric site
Site on the receptor that a drug classically binds to by the endogenous agonist
What is the difference between TOXIN and POISON and what are 2 examples of each?
Toxins are organic or biological substances from living organisms while poisons are non biologic substances
Toxins: puffer fish, mushrooms
Poisons: lead, cadmium, arsenic o
What physical characteristics of a drug influence how they act on receptors?
Size, shape, charge, atomic composition
Describe relative bond strengths
Covalent > electrostatic > hydrophobic
Covalent are often irreversible
Electrostatic bonds are more common (ionic, hydrogen, or dipole)
Hydrophobic are weak, uncharged, and require
Bond strength is inversely related to specificity
What is a racemic mixture? Correlate stereoisomerism and difference in drug effects.
Solutions of 2 or more (stereo)isomers (mirror images) with similar formulas that are combined and administered as a single drug. One stereoisomer may cause a desired effect when bound while another may not bind or bind differently to cause unwanted effects.
Ex-
S (Left hand) Ketamine= more potent, so produces more SE
R (Right hand) Ketamine= less potent, more pure, produces less SE
What is the difference between a competitive inhibitor and an allosteric inhibitor?
Competitive inhibitor- binds directly to the receptor site that the agonist binds to, can be surmountable (weaker bonds or lower doses) or insurmountable (covalent or large doses)
Allosteric inhibitor- binds to a receptor protein somewhere other than receptor site, making the agonist incapable of competing or surmounting the inhibition
What does EC 50 measure?
The point in which 50% of the drug effect is seen
What does Kd represent?
The point in which 50% of receptors are occupied
This value never changes within individual drugs, but differs between drugs
The lower the Kd the higher affinity the drug has to the receptor
Physiologic Antagonism
When a substance produces effects that counteract those of another substance by binding to different receptors
Ex: epinephrine raises HR and beta blockers lower HR by working on different receptors
What is a partial agonist?
Drug that binds to receptor with less affinity than a full agonist, eliciting a lesser response even when 100% of receptors are bound
These are competitive
and will act as antagonist in the presence of a full agonist because it will take up receptors that could be occupied by full agonist, therefore lowering the response
What is an inverse agonist?
Drug that binds to receptors and turns them “off”, effectively blocking the receptors from being turned on.
Lowers constitutive activity
Examples of receptor sites that these can effect: GABA, Histamine (H1, H2)
What is Emax? Can this value change?
The maximum drug effect
No, this value does not change
Define Toxicology
Undesirable effects that drugs have on a living system
Who is Imhotep?
First recorded physician