You are counseling a patient who is to begin taking phenytoin (Dilantin) for epilepsy/ Which statement by the patient indicates understanding of your teaching?

A. Phenytoin (Dilantin) can cause gingival hyperplasia, which is overgrowth of the gum tissue. Regular brushing and flossing helps prevent or minimize this side effect, demonstrating that the patient understands an important aspect of self-care while on this medication. B. Alcohol can interact with phenytoin, increasing the risk of seizures or affecting drug levels. Patients should avoid alcohol while taking phenytoin, even in moderation. C. Phenytoin has nonlinear (zero-order) pharmacokinetics, meaning that once therapeutic blood levels are reached, small changes in dose can lead to large changes in serum concentration. Maintaining therapeutic levels is not necessarily easy and requires monitoring. D. Rashes can be a serious side effect, potentially signaling Stevens-Johnson syndrome or toxic epidermal necrolysis, which are medical emergencies. Patients must report any rash immediately rather than dismiss it as minor.