Eptoin is a good drug for seizure and is time tested. Leokopenia ( a low WBC count
) is one of the adverse reaction to Eptoin. It is not common but can occur. The best way is to stop the eptoin as of now and start some other drug as there are many new and safe drugs for epilepsy
available in the market. A viral fever
may lower the counts but when there is an obvious relation with the onset of the drug, one has to be come cautious. May be you can assert that you want the eptoin to be shifted to valproate
Hope I am able to solve your concerns. Hope your wife gets well soon.