Explain the reason why some drug agents such as phenytoin (Dilantin) and valproic acid (Depakene) can produce greater pharmacologic effects when administered with other drugs that are highly plasma protein bound.

Question

Quizplus · Accepted Answer

Carbamazepine, phenobarbital, and phenytoin cause microsomal enzyme induction and increase the rate of metabolism of any other drug requiring microsomal metabolism. Some antiepileptic drugs, such as phenytoin and valproic acid, are highly plasma protein bound. They can displace and be displaced by other drugs that are also highly protein bound. This increases the free drug concentration (unbound fraction) of the drug displaced and produces greater pharmacologic effects.

Explain the Reason Why Some Drug Agents Such as Phenytoin