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Pharmacology
Dr. Hinkle Day 2
87
Medical
Undergraduate 3
01/21/2009

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Cards

Term
What is drug clearance?
Definition
volume of fluid clearing out of the body. same as excretion
Term
What is Duration?
Definition
How long the drug will work
Term
What is Half-Life?
Definition
how long it takes to get rid of 1/2 the drug
Term
ED 50/EC 50 (effective dose/effective concentration)
Definition
the does of a drug which induced a specific clinical effect in 50% of subjects
Term
What is LD 50 (lethal dose)
Definition
dose of a drug that induces death or toxicity in 50% of subjects
Term
What is Therapeutic Index?
Definition
a measure of the safety of a drug
Term
What is the Margin of Safety?
Definition
the margin between therapeutic and lethal dose
Term
What is a Single-Dose Time Course?
Definition
duration of effects determined by the combination of metabolism and excretion
Term
how many half lives does it usually take for a drug to plateau?
Definition
3-5 days
Term
what is a Trough?
Definition
where the graph of half-lives dips slightly before it plateaus
Term
What is Maximum Efficacy/Effectiveness?
Definition
the largest effect that a drug can produce
Term
What is Relative Potency?
Definition
Hiw much a drug must be given to achieve the desired response
Term
If you need less mg of a drug to get a response is that drug less or more potent?
Definition
More
Term
What is the Steady State?
Definition
The amount of drug in is equal to the drug that comes out.
Term
What are therapeutic drug levels?
Definition
Dose large enough to lock onto enough receptors to get the desired results
Term
What is Toxic Concentration?
Definition
the Plasma level at which toxic effects begin
Term
What is Albumin
Definition
protien found in the blood
Term
If you have less Albumin (protien) in your blood, is the drug more or less active?
Definition
more active
Term
Is an unbound drug active or inactive?
Definition
active
Term
Is a bound drug active or inactive?
Definition
inactive
Term
What is Distribution?
Definition
The movement of drugs throughout the body
Term
What is Creatinine Clearance?
Definition
How well the kidneys work and will clear a drug.
Term
Glomerular Filtration Rate (GFR)
Definition
affected by blood pressure
Term
What is excretion?
Definition
removing the drug from the body.
Term
Where does excretion take place?
Definition
Liver and Kidneys
Term
What are special considerations (5) in patients that you should consider in drug metabolism?
Definition
- Age
- Induction of drug metabolizing enzymes
- First pass effect
- Nutrition
- Drug competition
Term
What is a drug inhibitor?
Definition
Decreases enzyme activity
Term
What is a drug inducer?
Definition
Increases enzyme activity
Term
Cytochrome P450
Definition
the liver enzyme system
Term
Where does most drug metabolism take place in the body?
Definition
liver
Term
What is metabolism?
Definition
the way the body alters the drug
Term
What is a competative antagonist?
Definition
Reduces the amount of agonist required to produce any given intensity of response
Term
What is a noncompetitive antagonist?
Definition
Decreases maximal response achieveavke with an agonist
Term
What is an antagonist?
Definition
prevents receptor activation
Term
What is an agonist?
Definition
active receptors
Term
What are 8 patient factors affecting pharmocokinetics?
Definition
- weight and body composition
- age
- pregnancy
- smoking
- alcohol
- liver function
- kidney function
- psychosocial factors
Term
94% of the drug in the body will be eliminated in how many half-lives?
Definition
3-4 half-lives
Term
What is the peak of a drug?
Definition
The amount of time to maximize the efficiancy of drug
Term
What is the Onset of the drug?
Definition
amount of time needed for the drug to start working
Term
What is the timing of a drug?
Definition
Giving the drug at the right time so it can start working but not expire while you are giving treatment
Term
What 4 factors affect Plasma Drug Levels?
Definition
- Loading dose
- Maintenance dose
- timing
- special considerations
Term
What is toxic concentration?
Definition
Plasma level at which toxic effects begin (too many receptors were activted)
Term
What is the Minimum Effective Concentration?
Definition
plasma drug level which below, therapeutic effects will not occur.
Term
What is a Loading Dose?
Definition
the initial dose of a drug that is higher than a normal dose to achieve therapeutic levels quickly
Term
Where does most drug metabolism take place?
Definition
liver
Term
What system, in the liver, is responsible for the metabolism of drugs?
Definition
The hepatic microsomal enzyme system...or the P450 system.
Term
How many enzyme systems does the P450 system have?
Definition
12
Term
Which systems of the P450 system metabolize meds?
Definition
CYP 1,2,3
Term
What do the other 9 families of the P450 system metabolize?
Definition
endogenous compounds...such as steroids and fatty acids
Term
Do Hepatic microsomal enzymes ever make a larger molecule?
Definition
yes, they can make a molecule larger than the parent drug.
Term
What organ is the major player in drug excretion?
Definition
kidneys
Term
What does the kidneys have a hard time excreting?
Definition
Lipid-soluble drugs
Term
Can the liver enzymes make a pharmaceutical drug inactive?
Definition
yes
Term
Give an example of increased therapeutic action.
Definition
Codeine into morphine
Term
Is a prodrug active, inactive, highly active, or subclinically active?
Definition
inactive
Term
At what age does the liver develop its full capacity to metabolize drugs?
Definition
1yr.....prior to this time, infants must be handled with extreme care since they are limited.
Term
What is the process of induction?
Definition
when the liver is stimulated to produce more drug-metabolizing enzymes.
Term
What is the first-pass effect?
Definition
Refers to the hepatic inactivation of certain oral drugs. If the capacity of the liver to metabolize a drug is extremely high, that drug can be completely inactivated on its first pass through the liver.
Term
What is sometimes the outcome of first-pass?
Definition
A drug could have no therapeutic effect
Term
How do we bypass the first-pass effect?
Definition
We administer parenterally....this permits the drug to bypass the liver, allowing it to reach therapeutic levels in the systemic blood.
Term
What is the relationship to malnourishment and cofactors?
Definition
Malnourishment can lead to a deficiency in cofactors, which cause drug metabolism to be compromised.
Term
When drugs compete for the same metabolic pathway, what is the two main concerns?
Definition
The rate at which both drugs are metabolized could be decreased....and secondly, dangerous levels could be accumulated if the metabolism is decreased too much.
Term
What non-renal route of drug excretion can cause the most harm?
Definition
Breast milk....potential to expose a nursing infant to drugs.
Term
Which drugs play a larger role in breast milk....protein bound, lipid-soluble,ionized, or polar?
Definition
Lipid-soluble
Term
Which excretion routes have the least significance?
Definition
sweat and saliva
Term
What is the issue with the bile route of excretion?
Definition
Some drugs can be reabsorbed into the blood through the intestine, which could substantially prolong a drug's sojourn in the body.
Term
Experience has shown that, for most drugs....
Definition
there is a direct correlation between therapeutic and toxic responses and the amount of drug present in the plasma.
Term
Can we measure drug concentrations at the sites of action?
Definition
no
Term
What are the two plasma drug levels that are of special importance?
Definition
Minimum effective concentration and Toxic concentration
Term
To be of benefit, a drug must be present at or above the what?
Definition
MEC...Minimum effective concentration
Term
What is the objective of drug dosing?
Definition
To maintain plasma levels in the therapeutic range
Term
Drugs that have a narrow therapeutic range are easy to administer? T or F
Definition
False, the wider the range the safer the drug.....e.g. acetaminophen vs lithium....tylenol is much more safer than the lithium (bipolar drug) because lithium has a much narrower therapeutic range.
Term
What are the two things responsible for how long drug effects persist?
Definition
metabolism and excretion
Term
What is half-life?
Definition
The amount of time it takes for a drug in the body to decrease by 50%.
Term
Drugs with short half-lives leave the body very slowly? T or F
Definition
False, since 50% of the drug is decreased in a short time, it only makes since that the rest of the drug will be following the same path and be excreted in a short time as well.
Term
What are the three ways in which drugs can pass the membranes of the cells?
Definition
Channels or pores, passage with the aid of a transport system, and direct penetration.
Term
Most drugs use channels and pores as their means of travel? T or F
Definition
False, most of the time they take the direct penetration route
Term
Who's the biggest pimp of all transport system carriers?
Definition
P-Glycoproteins AKA multidrug transporter protein, because they help out in so many ways.
Term
What makes a polar molecule polar?
Definition
A neutral outcome....the positive and negative charges even each other out in these particular molecules.
Term
What do we call a molecule that does have a net charge?
Definition
ion
Term
If a particular drug is more lipid soluble than another, does this mean it will have a faster absorbing rate?
Definition
yes
Term
If a particular drug has a large molecular weight, does this mean it will absorb faster?
Definition
no, it will be less absorbant
Term
The amount of time needed to start working for a drug is called peak? T or F
Definition
False, it's called onset
Term
What do you call the length of time a drug is therapeutic?
Definition
Duration
Term
How much of the drug will be out of the system within 3-4 half-lives?
Definition
94%
Term
Does an agonist activate or unactivate receptors?
Definition
activate
Term
What is potentiation?
Definition
A drug which has no effect that enhances the effect of a second drug.....0+1=2
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