Question

Phenobarbital is the longest established anticonvulsant medication that is still used commonly to treat certain types of epilepsy. Following long-term treatment with phenobarbital, liver microsomal enzymes are ‘induced’ or up-regulated in terms of their activity. In view of this phenomenon, indicate what changes (increase, decrease or none) you would expect to occur in the following pharmacokinetic parameters for phenobarbital in an epileptic patient that has undergone six months of phenobarbital treatment compared to when they first started taking the drug. You should assume that microsomal enzyme induction has taken place in this person over the course of the six months. Please explain the reasoning behind your answers and provide literature support if available.

            a) hepatic clearance of phenobarbital (10 pts)

Answer 1

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