Depakote/Valproates in the liver?

[DLCarbone]

How long does it take for Depakote (valproic acid/Depakene, et.al) to FULLY metabolize through the liver?
Thanks:
Denise

[Abhijeet Deshmukh, MD]

Hello.

Half life of a drug is a time period in which half of the drug is metabolized from the body and eliminated. For example, let's say the half life of Drug A is 5 hours and you have taken 10mg dose. In the next 5 hours, only 5mg of the drug will remain in the body. In another 5 hours only 2.5mg will remain and then 1.25mg and so on.

It takes about 4 -5 half lives for the drug to be completely metabolized. Hence in the case of Depakote, since the half life is 16 ± 3 hours (lets take a maximum of 19 hours), the time for complete metabolism will be 19 X 5 = 95 hours. That means 4 complete days.

Regards

[DLCarbone]

Sorry, I am not a doctor or pharmacist.  Can you put that in lay-man's terms for me?
Thanks~denise

[Abhijeet Deshmukh, MD]

Hi.

Please ignore the above post. It was not meant for you. There was an error in transcription and you got this weird response. I apologize for this.

Here's the extract from www.rxlist.com about valproate, ".......Mean plasma clearance and volume of distribution for total valproate are 0.56 L/hr/1.73 m2 and 11 L/1.73 m2, respectively. Mean terminal half-life for valproate monotherapy after an intravenous infusion of 1000 mg was 16 ± 3.0 hours.

The estimates cited apply primarily to patients who are not taking drugs that affect hepatic metabolizing enzyme systems. For example, patients taking enzyme-inducing antiepileptic drugs (carbamazepine, phenytoin, and phenobarbital) will clear valproate more rapidly. Because of these changes in valproate clearance, monitoring of antiepileptic concentrations should be intensified whenever concomitant antiepileptics are introduced or withdrawn. ......"

It takes about 4-5 half lives of for the drug to be completely eliminated.

Regards