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#1
12-10-2011
 USMLE Forums Guru Steps History: --- Posts: 332 Threads: 48 Thanked 168 Times in 107 Posts
Drug half life

drug half life = volume of distribution divided by clearance

Can anyone explain why?

#2
12-10-2011
 USMLE Forums Scout Steps History: Not yet Posts: 46 Threads: 3 Thanked 34 Times in 20 Posts Reputation: 44

This is an approximate relationship that holds for drugs in a 1-compartment analysis model.

In this model we know that the drug concentration follows D = (D0)e^(-kt)

We also know that CL = Dose/AUC while Vd = Dose/D0

AUC = - D0/k which means CL/Vd = -1/k

Terminal Half-life = ln2/k = -ln2 CL/Vd
 The above post was thanked by: usluipek (12-10-2011)
#3
12-10-2011
 USMLE Forums Guru Steps History: --- Posts: 332 Threads: 48 Thanked 168 Times in 107 Posts

Thanks A Littel Tea Pot, but I do not quite understand what each symbols in your explanation represent.

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