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Old 03-31-2013
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Drug Calculate the drug loading dose?

Can't remember if this was posted but here goes:

At a target concentration of 7.5 mg/L of theophyline is required by a 60kg patient. What is the loading dose given the following:
Vd= 0.5 L/kg
Cl= 0.04 L/kg/hr
t1/2= 9.3 hrs
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Old 03-31-2013
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LD=CpxVd/F
LD=7.5x0.5=3.75mg/Kg=225mg
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Old 03-31-2013
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Loading dose= Vd x Cp / f

lets assume bio-availability is 1

Loading dose = 0.5 x 7.5 / 1 = 3.75 mg
so

loading dose = 3.75 mg

according to weight 3.75 x 60 = 225 mg
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Quote:
Originally Posted by MedicalExaminer View Post
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LD=CpxVd/F
LD=7.5x0.5=3.75mg/Kg=225mg

thasts right but am confused here pls explain this question one for me;

Q:if drug is known to be distributed into TBW, what dose (mg) is needed to obtain an initial plasma level of 5mg/L in patient weighing 70kg?

a)210
b)150
c)110
d)50
e)35
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Quote:
Originally Posted by neha_subh View Post
thasts right but am confused here pls explain this question one for me;

Q:if drug is known to be distributed into TBW, what dose (mg) is needed to obtain an initial plasma level of 5mg/L in patient weighing 70kg?

a)210
b)150
c)110
d)50
e)35
answer of that question is:
A)210

This is loading dose question.
since the patient weighs 70kg and 60% TBW,he has 42 L (70L X 60%) Of TBW.

NOW
LD = Vd x Cp

LD = 42L X 5mg/L = 210mg
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Old 03-31-2013
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Quote:
Originally Posted by OMGStep View Post
Can't remember if this was posted but here goes:

At a target concentration of 7.5 mg/L of theophyline is required by a 60kg patient. What is the loading dose given the following:
Vd= 0.5 L/kg
Cl= 0.04 L/kg/hr
t1/2= 9.3 hrs

Loading dose = Cp X Vd /F

= 7.5 mg/L X 0.5 L/Kg / 1

= 3.75 mg / Kg

Now times this by 60 Kg to get rid of Kg.

3.75 mg/Kg X 60 Kg

= 225 mg is my answer. Don't know if I'm right or wrong.
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Old 07-17-2013
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Quote:
Originally Posted by neha_subh View Post
answer of that question is:
A)210

This is loading dose question.
since the patient weighs 70kg and 60% TBW,he has 42 L (70L X 60%) Of TBW.

NOW
LD = Vd x Cp

LD = 42L X 5mg/L = 210mg
==========
Please Nena help me with this one, im so confused
why do you multiply 70 by the porcentage of water?
please someone explain, im stuck here
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