Intro class Flashcards
True/False? The definition of a Drug: ANY substance with an effect on living cells
True
Define pharmacology
All aspects of drugs and their interactions with living organisms
What are the three main (clinical) uses of drugs?
Therapy (treating conditions)
Diagnosis
Prophylaxis of disease
What is the key competency of therapy?
There must be a balance between benefit and risk
What properties of a drug must we know to use it properly? (4 things)
Pharamcodynamics
Pharmacokinetics
Efficacy
Safety
List the 5 types of chemical bonds in order of decreasing strength
Covalent bonds Ionic bonds Hydrogen bonds Hydrophobic interactions Van der Waals Forces
Name 6 different molecular drug targets
Receptors Enzymes Carrier molecules (symport/antiport) Ion channels (ligand- or voltage-gated) Idiosyncratic targets (metal ions, surfactant proteins, gastrointestinal contents) Nucleic acids
True/False? A dose-response curve is nearly linear when concentration is plotted logarithmically.
True
True/False? Positive allosteric modulators (PAM) and Negative allosteric modulators act on the allosteric site to create or end a response.
False, they Modulate response
Describe the Therapeutic Index and two ways to calculate it
The relative concentration difference between therapy and toxic effects
1) TI = LD50/ED50
2) TI = TD01/ED99
True/False? A higher Therapeutic index implies an increased margin of safety
True
What is the main point of that complicated flowchart demonstrating the factors influencing drug concentrations?
Multiple compartments = unequal distribution
What is the difference between an active drug and a prodrug in terms of 1. Activity? 2. Metabolism?
- Active drugs are active
Prodrugs are not active - Active drugs are metabolised into inactive drugs
Prodrugs are metabolised into active drugs
Why does metabolism differ between individuals?
Genetic variation
Define the MEC
Minimum effective concentration (can relate to a specific effect)
Define pharmacokinetic intensity
The distance between the response MEC and its peak effect
Define therapeutic windwo
Distance between response MEC and toxic MEC
Describe the difference between pharmacokinetics and pharmacodynamics
pkinetics: How a drug gets to its target site (ADME)
pdynamics: What a drug does at its active site
What is the equation for apparent volume of distribution?
Vd = Dose/C
usually Cplasma
What is a half life?
The time it takes for 50% of a drug to be eliminated from the body
How many half lives does it take for the drug to be considered “eliminated” from the body?
4
50 + 25 + 12.5 + 6.25 = 93.8%
Define drug clearance
The amount of blood cleared of drug per unit time
Calculated by rate of drug disappearing from plasma/drug conc in plasma
What is a drug’s maintenance dose and how is it calculated?
The rate and dose of which you need to keep administering to stay within the therapeutic window
Maintenance dose: target concentration x clearance
or
target conc x (elimination rate/plasma conc)
Describe the pathway an orally administered drug takes to get into systemic circulation and note when some of that dose is lost
Oral dose -> GI tract -> absorption* -> portal vein -> liver** -> systemic circulation
- stomach absorption depends on pH solubility of drug
- first pass metabolism, most of the drug extracted