Patients taking Dilantin should be aware of ______ as a common side effect.

Patients taking Dilantin (phenytoin) commonly experience gingival hyperplasia, which is the overgrowth of gum tissue. This side effect can occur with long-term therapy and may be exacerbated by poor oral hygiene. Regular dental care, proper brushing, and flossing help minimize this effect while continuing seizure management.