Exam 1 material Flashcards
Who is considered to be the father of modern medicine?
Hippocrates
What Greek god and artifact did the medicine logo come from?
the rod of Asclepius
What is Materia Medica?
It is the precursor to a pharmacology text. It contains a body of knowledge throughout history of botany and medicinal substances.
Define pharmacodynamics
What the drug does to the body
Who is the father of Toxicology?
Paracelsus
Define pharmacokinetics
What the body does to the drug
Define pharmacogenomics and give an example
How the body responds to the drug given our genetics. Example: HER2 positive breast cancer.
What is the difference between a poison and a toxin?
Toxins are organic and poisons are inorganic materials
What four characteristics contribute to the lock and key mechanism of receptor interactions?
Size, shape, electrical charge and atomic composition
List 4 different bond types in order of bond strength (strong to weak)
Covalent bonds (strongest), ionic bonds, hydrogen bonds, hydrophobic bonds (weakest)
What is an isomer and give an example?
Two molecules with the same chemical formula. Example fructose and glucose
What is an optical isomer?
Isomers that are mirror images of one another. They do not behave the same in the body however.
What is a racemic mixture and give an example
A mix of optical isomers. Example: S and R ketamine. S-ketmaine is the purified form and 4x more potent than R-ketamine, which has the toxic side effects we associate with ketamine
What is an orthosteric interaction?
When a drug binds to the active site of the receptor
What is an allosteric interaction?
When the drug or agonist binds a site adjacent to or outside of the active site
What is non specific binding and give an example of an endogenous molecule that facilitates this
Non-specific binding can occur simultaneously but is outside of receptor-agonist binding (which has a limit when receptor sites are saturated). Albumin can facilitate non-specific binding.
What are the 4 things we look at when studying pharmacokinetics?
Absorption, Distribution, Metabolism, and Excretion
What is Emax?
Emax is the maximum effect of the drug. This number can be variable. EC50 is a single point.
When looking at the drug concentration response curve, what is EC50?
EC50 is the concentration of the drug where it has reached 50% of its maximum effect
When looking at the concentration response curve, what is Kd?
Kd is the dissociation constant. Kd is the concentration of the drug where 50% of the receptors are bound.
What is Bmax?
Bmax is where receptors are 100% bound or saturated. Only non specific binding can occur at this point.
If a drug has a low Kd what does that mean? A high Kd?
A drug with a low Kd is said to have high affinity for the receptor. A high Kd corresponds with a drug that has a low affinity for binding the receptor
What is an allosteric activator and give an example of one?
An allosteric activator is an agonist that binds to a site outside of the active site and potentiates the the activity of that protein bound active site. Example, both benzos and general anesthesia bind GABA receptors and these regulatory sites produce positive allosteric modulation such that the activity of GABA is potentiated.
What is a competitive antagonist? Give an example
Antagonists that bind the active site of a receptor. These interactions are surmountable if you increase the amounts of agonist given. Propranolol to isoproterenol.
Give an example of how a competitive antagonist interaction can be irreversible…
When an antagonist binds the active site (orthosteric) and forms a covalent bond.
What is a non-competitive antagonist? Give an example
Antagonists that bind outside the active site (allosteric). These are irreversible and insurmountable. Phenoxybenzamine to norepinephrine.
What is a partial agonist and what problems can they pose to agonists?
A partial agonist produces a lower response at full receptor occupancy. They can out-compete full agonists and can actually act as antagonists in the presence of full agonists.
Give an example of antagonism by administration of an opposing charge…
Protamine, which carries a positive charge can be given in the event of an overdose of heparin, which has a negative charge. Protamine binds the heparin and renders it ineffective in the clotting cascade.
What is physiologic antagonism and give an example…
When two compounds bind to two different receptors and have opposite effects. Example: Epinephrine can bind beta receptors and increase HR while acetylcholine can bind muscarinic receptors and decrease the HR.
Describe receptor configurations in pharmacodynamics
Receptors can be active or inactive. Physiologically the inactive configuration tends to win favor. Agonists will activate the receptors turning them “on”
What is an inverse agonist?
These are agonists that “inactivate” receptors or turn them “off” In practice these act as antagonists but in theory they are agonists as they elicit a response by turning “off” the receptor favoring the inactive form.
Graphically what effect do antagonists and inverse agonists have on constitutive activity of a receptor?
Competitive antagonists bring the receptor activity back down to constitutive activity. Inverse agonists lower that receptor’s activity below the constitutive activity threshold.
Take Beta-1 receptors and give an example of an agonist (direct and indirect), partial agonist, antagonist, and inverse agonist…
Agonist: Epinephrine (direct), amphetamines (indirect)
Partial agonist: Pindolol
Antagonist: Propranolol
Inverse agonist: Carvedilol
List 3 scenarios that can dictate the duration of drug action…
- How long the drug binds the receptor
- How long downstream effectors last (these can be degraded/used up)
- Desensitization occurs (signals are dampened)
What is special about albumin?
It is a large carrier protein. It has two inert binding sites (these do not elicit a response). It binds mostly to acidic drugs
What is the difference between potency and efficacy?
Potency is the drug concentration required to produce 50% of that drugs maximal effect. Efficacy describes the maximal response a drug can deliver. Efficacy is more important.
What is the therapeutic index?
The TI is a ratio. The median toxic dose (TD50) over the median effective dose (ED50). The larger the ratio, the safer the drug.
List a few causes of variations in drug responsiveness
Drug-drug interactions (polypharmacy), genetics, tolerance (tachyphylaxis/quick tolerance), body composition
if pH is greater than a drug’s pKa what happens?
The drug favors its unprotonated form, donates a H+ to it’s basic environment
if pH is less than a drug’s pKa what happens?
The drug favors it’s protonated form as it picks up a H+ from its acidic environment
Which form of aspirin (weak acid pKa = 3.5) is favored in the stomach (pH = 1.5), in the intestine (pH = 6.5) and will it be charged or uncharged?
In the stomach it’s protonated form, uncharged.
In the intestine it will be unprotonated and charged
Which form of morphine (weak base pKa is 7.9) is favored in the stomach (pH = 1.5), in the blood (pH = 7.4) and will it be charged or uncharged?
In the stomach it will be protonated and charged.
In the blood it will be slightly protonated and charged as well or in equilibrium.
List a few reasons biologic drugs are in vogue…
They are very targeted (high specificity)
There are less adverse effects associated with these drugs
Increased efficacy
They can be used to cause cell death
What are biologics (drugs that use monoclonal antibodies) used to treat?
Asthma, migraines, cancer
How are monoclonal antibodies made?
- isolate a protein from a human
- inject that protein into another living thing which will generate an immune response and produce antibodies
- Take a spleen cell (antibody producing cell) and fuse it with a myeloma cell (immortal cancer cell)
Describe the process of clinical testing
- In vitro studies to find a lead compound
- Animal testing (can take 2 years)
- Apply for an IND
- Phase 1: healthy subjects
- Phase 2: patients as subjects
- Phase 3: clinical trials and placebos as controls, double blind
- Apply for NDA (can take a year)
- Marketing and post-marketing surveillance (phase 4)