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Old 11-22-2012
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Default Reduced renal clearance

A 67 yr old pt with heart failure is receiving digoxin at a daily dose of 0.25 mg orally. His digoxin plasma concentration is reported at 1.2 ng/ml after steady state conditions have been reached (therapeutic range is 0.5-1.5 ng/ml) You are asked to evaluate this pts treatment after it has been determined that his renal function has declined, with a creatinine clearance now 25% of normal. What would you recommend with regard to the daily dose of digoxin?


oReduce the daily dose by 25% and recheck levels
oStop digoxin due to the risk of toxicity in renal failure
oReduce the daily dose to 0.125mg and recheck levels
oContinue the same daily dose and recheck levels
oReduce the daily dose by 75% and recheck levels
oReduce the daily dose by 50% and recheck levels


p.s. i don't actually have an answer for this question but i have a guess. I wanna know what you guys think.
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Default Discontinue medication

i think thats the teaching?
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Old 11-22-2012
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Quote:
Originally Posted by blade View Post
i think thats the teaching?
what do u mean
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Old 11-22-2012
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Quote:
Originally Posted by SarahM View Post
what do u mean
I mean option 2'stop the treatment '
Reducing the dose would not stop the toxicity in this elderly pxt who already has renal compromise.
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Old 11-22-2012
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Quote:
Originally Posted by SarahM View Post
A 67 yr old pt with heart failure is receiving digoxin at a daily dose of 0.25 mg orally. His digoxin plasma concentration is reported at 1.2 ng/ml after steady state conditions have been reached (therapeutic range is 0.5-1.5 ng/ml) You are asked to evaluate this pts treatment after it has been determined that his renal function has declined, with a creatinine clearance now 25% of normal. What would you recommend with regard to the daily dose of digoxin?


oReduce the daily dose by 25% and recheck levels
oStop digoxin due to the risk of toxicity in renal failure
oReduce the daily dose to 0.125mg and recheck levels
oContinue the same daily dose and recheck levels
oReduce the daily dose by 75% and recheck levels
oReduce the daily dose by 50% and recheck levels


p.s. i don't actually have an answer for this question but i have a guess. I wanna know what you guys think.
Reduce daily dose by 75%
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Old 11-22-2012
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About 60% of digoxin is excreted in the urine; the rest is metabolized in the liver.

Decrease in Creatinine Clearance to 25% of normal means that Renal Cl of Digoxin will be 25% of normal


Total Cl= Cl (Renal) + Cl(Liver)= 0.25x0.6Cl + 0.4Cl=0.55Cl


So the new Cl is 55% of normal


Maintenance dose is proportional to the Clearance. So it has to be reduced by 55%


So i would go with answer (F) Reduce the daily dose by 50% and recheck levels


(There is an example in Katzung Pharmacology)
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