The Client Has Epilepsy and Is Prescribed Phenytoin (Dilantin)

The client has epilepsy and is prescribed phenytoin (Dilantin) .The client has been seizure free and asks the nurse why he still needs blood tests when he is not having seizures.Which response by the nurse is the most appropriate?

A) Dilantin can cause blood thinning in some people."
B) There is a narrow range between a helpful dose of this medication and a dose that could make you feel sicker."
C) Dilantin tends to lower blood levels of potassium."
D) This medication can cause a severe skin reaction called Steven-Johnson syndrome if doses are too high."