Shared Flashcard Set

Details

Dose Adjustment in Renal and Hepatic Insufficiency
Hematology and Urology Test
26
Pharmacology
Graduate
04/03/2011

Additional Pharmacology Flashcards

 


 

Cards

Term
Normal creatinine
Definition
0.5-1.5
Term
Analytical factors that may alter the measurement of creatinine clearance
Definition
Glucose, protein, pyruvate, frutose, uric acid, cephalosporins
Term
Physiologic factors that may affect the measurement of creatinine clearance
Definition
Age, weight, gender, exercise, diurnal variation (SCr levels are highest around 7pm and lowest in am), drugs (cimetidine, trimethoprim, probenecid)
Term
Measurement of creatinine clearance
Definition
24 hr urine collection; very accurate by inconvenient;
CrCl (mL/min) =(UCr x Uvol)/(SCr x T)
Term
Equation for IBW
Definition
Males: 50 + [2.3 x (height - 60)]
Females: 45.5 + [2.3 x (height - 60)]
Term
Equation for CrCl
Definition
CrCl = [(140-age) x IBW] / (72 x SCr)
Take times 0.85 for females
Term
Normal creatinine clearance
Definition
100-125 mL/min
Term
Effect of renal disease on absorption
Definition
Decreased gastric emptying, decreased gastric pH, N/V/D, GI edema
Term
Drugs that have decreased absorption with renal disease
Definition
Furosemide, Pindolol
Term
Drugs that have incresed absorption with renal disease
Definition
Dextropropoxyphene, Dihydrocodiene
Term
What are three ways that renal disease affects distribution?
Definition
Changes in serum protein binding, changes in tissue protein binding, changes in body/fluid composition
Term
How is the distribution of acidic drugs affect in renal failure?
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)
Term
How are changes in tissue protein binding and the volume of distribution affected in renal insufficiency?
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
Term
How do changes in body/fluid composition affect drugs in renal insufficiency?
Definition
Fluid retention leads to an increased volume of distribution for hydrophilic drugs (need to increase the dose)
Term
Examples of drugs with renal metabolism (the dose of these drugs will have to be decreased with renal insufficiency)
Definition
Vitamin D, insulin, imipenem
Term
Drug with non-renal metabolism that will still have reduced metabolism with renal failure (need to decrease the dose)
Definition
acyclovir
Term
Drugs with renal elimination of metabolite (two most important)
Definition
Codeine/morphine, meperidine (also... allopurinol, cefotaxime, chlorpropramide, procainamide, sulfonamides, theophylline)
Term
Examples of drugs that are eliminated by kidneys (need to decrease dose for renal insufficiency)
Definition
Cimetidine/amantadine/ranitidine and aminoglycosides (aminoglycosides are especially important because they cause renal toxicity)
Term
Factors that affect the dialysis of drugs
Definition
Molecular weight, water solubility, protein binding, volume of distribution
Term
What are the three ways that elimination of drugs can be affected by liver failure?
Definition
Hepatic blood flow (flow-limited), plasma protein binding, intrinsic metabolic activity (enzyme limited)
Term
How does hepatic blood flow affect elinination of drugs in hepatic disease?
Definition
Decreased blood flow through liver prevents drugs from even entering the liver to be metabolized (decreased first pass effect and increased bioavailability)
Term
How is plasma protein binding affected in liver disease?
Definition
Decreased production of albumin leads to increase in free drug concentration
Term
What are the two types of intrinsic metabolic activity?
Definition
Phase I: CYP450 is impaired (especially oxidation)
Phase II: conjugation, not affected
Term
What drugs may someone with hepatic insufficiency be more sensitive to?
Definition
benzodiazepines, analgesics, loop diuretics, beta blockers
Term
Reasons for decreasing the dose by 25% with liver disease
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
Term
Reasons for decreasing the dose by >25% with liver disease
Definition
Chronic administration
Narrow therapeutic range
Protein binding is significantly affected
Flow limited and given PO
Altered sensitivity due to liver disease
Supporting users have an ad free experience!