Term
1. clearance
2. volume of distribution
3. elimination half-life
4. bioavailability |
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Definition
| What are the four most important parameters governing drug disposition? |
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Term
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Definition
| What is the measure of the body's efficiency in eliminating drugs? |
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Term
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Definition
| What is a measure of the apparent space in the body available to contain the drug? |
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Term
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Definition
| What is a measure of the rate of removal of drug from the body? |
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Term
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Definition
| What is the fraction of the drug absorbed as such into the systemic circulation? |
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Term
Pharmacokinetics
*usually reflected in the plasma concentration |
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Definition
| What is the study of the time course of drug concentration in the body? |
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Term
First order kinetics
(aka Exponential Kinetics)
*measured as the rate constant |
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Definition
| What type of kinetics is characterized by a constant fractional change per unit time? |
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Term
Zero order kinetics
(aka saturation kinetics) |
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Definition
| What type of kinetics is characterized by a constant amount of change per unit time? |
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Term
| half-time OR biological half-life |
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Definition
| What equals the time required for 50% of the drug remaining in the body to be eliminated? |
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Term
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Definition
| For drugs that are eliminated by first order kinetics, this is the fractional change per unit time. |
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Term
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Definition
| What is the volume of biological fluid that would have to be completely freed of drug to account for the rate of elimination? |
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Term
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Definition
| How is clearance measured? |
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Term
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Definition
| After any route of administration, except for IV, the absorption of most drugs follows which kinetics? |
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Term
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Definition
| Which pharmacokinetics model is the simplest and is useful for demonstrating the standard pharmacokinetic terms? |
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Term
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Definition
| Which pharmacokinetics model assumes that the distribution of drug is uniform and rapid compared with absorption and elimination? |
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Term
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Definition
| In the two compartment model of pharmacokinetics which compartment is elimination from? |
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Term
25mg
*50mg after 12 hours |
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Definition
| If a drug has a half life of 12 hours and 100mg is given, how much of the drug will be left after 24 hours. |
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Term
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Definition
| When a drug is first given, what is the term for the release of that drug from the matrix it was formed in by the company? |
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Term
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Definition
| What is the removal of a drug by biotransformation called? |
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Term
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Definition
| What is the volume of the dose of a drug that reaches the systemic circulation? |
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Term
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Definition
| What principle states that when a drug is administered IV, the plasma concentration will increase until the rate of elimination and administration are equal? |
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Term
| Steady-State concentration (Css) |
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Definition
| What equation = the dosing rate/clearance? |
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Term
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Definition
| How many half lives does it take to reach a steady state plateau? |
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Term
NO
*only the half life affects the plateau |
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Definition
| If you increase the dosage of a drug, would that increase the rate that the steady state is acheived? |
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Term
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Definition
| What types of drugs are used to mimic a continuous IV infusion? |
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Term
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Definition
| In fixed rate multiple dose regimens of drugs the drug will accumulate in the body if the time interval between doses is less than how many half lives? |
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Term
| the mean concentration of the drug during the dosing interval |
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Definition
| Since the plasma concentration fluctuates during fixed rate, multiple dose regimens, the Steady state concentration (Css) now represents what? |
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Term
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Definition
| For what route of administration will bioavailability affect the steady state concentration? |
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Term
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Definition
| What type of dosage would be used if it is clinically important to acheive therapeutic concentrations immediately? |
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Term
| Vd - Volume of distribution |
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Definition
| What is the variable that relates the toal drug concentration in the body to the plasma concentration? |
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Term
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Definition
| ________ = Css (steady state concentration) x Vd |
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Term
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Definition
| What type of elimination occurs when a drug exceeds the metabolic and/or excretory capacity of the body to eliminate the drug at a linear rate? |
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Term
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Definition
| Nonlinear elimination is onlly for ____ ____ drugs. |
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Term
plasma concentration - increase
time of elimination - increase |
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Definition
In nonlinear elimination if you increase the dose, what will happen to the plasma concentration?
to the time of elimination? |
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Term
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Definition
| For single doses of drugs given to pregnant women, peak fetal concentrations occur between what times? |
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Term
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Definition
| During which developmental stage would you worry about the kidneys not being able to function well enough to excrete a drug? |
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Term
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Definition
| During which developmental stage is the average metabolism reached? |
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Term
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Definition
| What else should you consider that may affect drugs during the 12y-18y developmental stage? |
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Term
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Definition
| What happens to the absorption rates in the elderly? |
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Term
It will increase
*more fat in elderly ppl |
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Definition
| How will the distribution be affected in an elderly pt taking a lipophilic drug? |
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Term
It will decrease
*and will have a higher blood concentration |
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Definition
| How will the distribution of a water-soluble drug change in an elderly person? |
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Term
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Definition
| In the elderly population, what does drug metabolism do (usually)? |
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Term
It will be reduced
*making higher plasma concentrations |
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Definition
| For efficiently cleared, highly metabolized drugs what will happen to the first pass metabolism in the elderly? |
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Term
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Definition
| Estimates of glomerular filtration rate are generally obtained by estimating endogenous ________ clearance. |
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Term
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Definition
| What equation is the most common method of estimating creatinine clearance? |
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Term
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Definition
| What percentage of the creatinine clearance value calculated by the Cockroft-Gault equation would be correct for women? |
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Term
increased
*creatinine production decreases with aging |
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Definition
| Using the Cockroft-Gault equation on elderly people may show a(n) _________ result than is actually there? |
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Term
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Definition
| How much does creatinine clearance decrease per decade after age 30? |
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Term
| decreasing dose & maintaining dosage interval |
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Definition
| What type of dosage adjustment for a patient with renal impairment is preferred when a relatively constant plasma concentration of the drug is desired? |
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