Term
| of Vd, CL, and t1/2 -->INDEPENDENT or DEPENDENT VARIABLES? |
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Definition
Vd and CL--> INDEPENDENT
t1/2 --> DEPENDENT |
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Term
| what is the FOUR HALF LIFE RULE? |
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Definition
| a drug is considered to be essentially eliminated from the body after four half-lives |
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Term
| assuming a first-order process of drug elimination, the DURATION OF DRUG EFFECTS will be (in general) proportional to- |
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Definition
| proportional to its HALF-LIFE and to the ADMINISTERED DOSE |
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Term
| what two factors affect the rate of DRUG ELIMINATION? |
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Definition
1-termination of drug effect is related to a REDISTRIBUTION MECHANISM
2-drug effect depends on a slow turnover of a physiologic substance (e.g. an enzyme) involved in the expression of that effect |
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Term
| at the STEADY STATE, what is the relationship between the rate of elimination and the rate of infusion? |
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Definition
| they are equal (D/T = Css x CL) |
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Term
| is the TIME needed to reach the STEADY STATE EQUILIBRIUM independent or dependent upon DOSE, DOSE INTERVAL, and ELIMINATION HALF LIFE OF THE DRUG |
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Definition
| It is determined only by the elimination half-life of the drug |
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Term
| if the DOSING INTERVAL is shorter than 4 half-lives, what will occur? |
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Definition
| accumulation- each subsequent dose is added to the drug remaining in the body |
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Term
| when might it be necessary to reach a desired PLASMA CONCENTRATION in less than 4 half lives? how is this achieved? |
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Definition
1) the clinical situation is an emergency
2) the drug has a low therapeutic index
by giving larger LOADING DOSE, followed by MAINTENANCE DOSES that will keep the drug at desired SSC |
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