Term
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Definition
the number indicating the ratio between the lethatl dose(LD) and the therapeutic dose (TD): TI=LD 50/TD 50:
LD is the dose producing dealth in 50% of test animals; TD is the dose producing the desired therapuetic effect in 50% of test animals |
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Term
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Definition
| the relative distance between toxic and therapeutic dosage ranges. Drugs with a high TI are said to have a wide safety range; those with a low TI a narrow safety range |
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Term
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Definition
1. A truly puer drug contains only one specific chemical agent. Pure drugs are rarely attainable.
2. Additives may be needed to facilitate formulation or manipulate absorption.
3. Dusts or other contaminsants from the environment may enter the substance.
4. The kind and concentration of extraneous substances allowed are specified by standars of purity |
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Term
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Definition
1. Potency is generally dependent on the concentration of active drug in the medicinal preparation.
2. When active ingredients are unknown, potency is measured by testing in animals (bioassay)
3. When active ingredients are known, potency is measured by chemical assay |
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Term
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Definition
1. Refers to the % of active substances in a durg that is absorbed and becomes available to the target tissue following administration.
2. Factors influincing bioavailablility include particle size, crystalline strutcture, solubility, and polarity.
3. Blood or tissue concentrations at a specified time following administration are commonly used to measure bioavailablity
(consiquently consider drugs BIOLOGICALY EQUIVALENT when containing simmilar conc. in the blood and tissues at simillar times
THERAPEUTICLY EQUIVALENT when their are equall therapeutic results in a clical trial |
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Term
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Definition
1. The effectiveness of the drug in promting desirable clinical changes is called efficacy
2. Objective measures are rarley available for determining efficacy
3. Double-bind studies are needed to establish efficacy as distinguished from placebo effect |
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Term
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Definition
1. The incidence and severity of untoward(not favorable) effects attributed to the use of a drug determines the safety of that drug.
2. No active chemical is free of toxicity
3. The difference between the toxic and therapeutic dosages determines the margin of safety of a substance
4. When considering use of a drug, its untoward(not favorable) effects must be weighed against its benefits |
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Term
| Bilogical Half Life (t1/2) |
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Definition
| the time required to reduce to one half the amount of unchanged drug that is in the body at the time equilibirum is established. The rate of biotransformation and excretion of the drug determines the biologic half-life. |
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Term
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Definition
| Occurs when body can't metabolize one dose of a drug before another dose is administered |
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Term
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Definition
| Occurs when combined effect of two drugs produces a result that equals the sum of the individual effects of each drug. |
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Term
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Definition
| A drug interaction in which the combined effect of drugs is greater than the sum of each individual agent acting independently |
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Term
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Definition
| refers to concurrent administration of two drugs in which one drug increases the effect of the other drug |
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Term
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Definition
Any abnormal or peculiar response to a drug that may manifest itself by:
1. Overresponse or abnormal susceptibility to a drug.
2. Underresponse, abnormal tolerance.
3. A qualitatively different effect from the one expected.
4. Unpredictable and unexplanable symptoms |
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Term
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Definition
| study of the effect of substances on living systems |
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Term
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Definition
| deals with the relative effects of drugs in the human system for various disorders |
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Term
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Definition
| deals with experimental science pertaining to theories of drug action |
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Term
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Definition
| study of drugs's alterations during its trip through the body as it is absorbed, distributed, bound to or localized in tissues, biotransformed, and excreted |
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Term
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Definition
| study of genetically induced drug responses that are often responsible for some idiosyncratic responses |
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Term
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Definition
(FDA)-any substance for use in diagnosis, cure, relief, treatment, or prevention of a disease or condition
also any substance listed in the U.S.P. or British pharmacopedia and all substances other than food or devices capable of altering body structure or function |
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