Your dad has a high risk of seizure
recurrence after having suffered severe traumatic brain injury
in 2009 with prolonged ICU stay.
That risk is compounded when he misses his antiepileptic medication and consumes alcohol. Alcohol consumption itself can precipitate seizures.
The interaction between Phenytoin
and Alcohol is not very clear but acute binges of alcohol is thought to increase the serum phenytoin levels where as chronic alcohol use is thought to reduce serum phenytoin levels. It is necessary to measure Serum Phenytoin levels to check if its in the therapeutic range.He should continue taking Eptoin
to prevent seizures.