Term
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Definition
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Term
Analytical factors that may alter the measurement of creatinine clearance |
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Definition
Glucose, protein, pyruvate, frutose, uric acid, cephalosporins |
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Term
Physiologic factors that may affect the measurement of creatinine clearance |
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Definition
Age, weight, gender, exercise, diurnal variation (SCr levels are highest around 7pm and lowest in am), drugs (cimetidine, trimethoprim, probenecid) |
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Term
Measurement of creatinine clearance |
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Definition
24 hr urine collection; very accurate by inconvenient; CrCl (mL/min) =(UCr x Uvol)/(SCr x T) |
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Term
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Definition
Males: 50 + [2.3 x (height - 60)] Females: 45.5 + [2.3 x (height - 60)] |
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Term
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Definition
CrCl = [(140-age) x IBW] / (72 x SCr) Take times 0.85 for females |
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Term
Normal creatinine clearance |
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Definition
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Term
Effect of renal disease on absorption |
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Definition
Decreased gastric emptying, decreased gastric pH, N/V/D, GI edema |
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Term
Drugs that have decreased absorption with renal disease |
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Definition
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Term
Drugs that have incresed absorption with renal disease |
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Definition
Dextropropoxyphene, Dihydrocodiene |
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Term
What are three ways that renal disease affects distribution? |
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Definition
Changes in serum protein binding, changes in tissue protein binding, changes in body/fluid composition |
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Term
How is the distribution of acidic drugs affect in renal failure? |
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Definition
Plasma protein binding is decreased so there is an increase in free drug (must measure the unbound concentration to make sure that is in the therapeutic range) |
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Term
How are changes in tissue protein binding and the volume of distribution affected in renal insufficiency? |
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Definition
The volume of distribution is decreased because it is filled with all the stuff you aren't eliminated through your kidneys so you need to decrease the dose |
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Term
How do changes in body/fluid composition affect drugs in renal insufficiency? |
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Definition
Fluid retention leads to an increased volume of distribution for hydrophilic drugs (need to increase the dose) |
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Term
Examples of drugs with renal metabolism (the dose of these drugs will have to be decreased with renal insufficiency) |
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Definition
Vitamin D, insulin, imipenem |
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Term
Drug with non-renal metabolism that will still have reduced metabolism with renal failure (need to decrease the dose) |
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Definition
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Term
Drugs with renal elimination of metabolite (two most important) |
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Definition
Codeine/morphine, meperidine (also... allopurinol, cefotaxime, chlorpropramide, procainamide, sulfonamides, theophylline) |
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Term
Examples of drugs that are eliminated by kidneys (need to decrease dose for renal insufficiency) |
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Definition
Cimetidine/amantadine/ranitidine and aminoglycosides (aminoglycosides are especially important because they cause renal toxicity) |
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Term
Factors that affect the dialysis of drugs |
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Definition
Molecular weight, water solubility, protein binding, volume of distribution |
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Term
What are the three ways that elimination of drugs can be affected by liver failure? |
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Definition
Hepatic blood flow (flow-limited), plasma protein binding, intrinsic metabolic activity (enzyme limited) |
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Term
How does hepatic blood flow affect elinination of drugs in hepatic disease? |
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Definition
Decreased blood flow through liver prevents drugs from even entering the liver to be metabolized (decreased first pass effect and increased bioavailability) |
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Term
How is plasma protein binding affected in liver disease? |
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Definition
Decreased production of albumin leads to increase in free drug concentration |
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Term
What are the two types of intrinsic metabolic activity? |
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Definition
Phase I: CYP450 is impaired (especially oxidation) Phase II: conjugation, not affected |
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Term
What drugs may someone with hepatic insufficiency be more sensitive to? |
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Definition
benzodiazepines, analgesics, loop diuretics, beta blockers |
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Term
Reasons for decreasing the dose by 25% with liver disease |
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Definition
Not more than 40% eliminated by liver (if there’s no renal dysfunction) Flow limited and given IV Flow/enzyme limited and given acutely PO Large therapeutic range |
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Term
Reasons for decreasing the dose by >25% with liver disease |
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Definition
Chronic administration Narrow therapeutic range Protein binding is significantly affected Flow limited and given PO Altered sensitivity due to liver disease |
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