The nurse is educating a client prescribed phenytoin. Which statement would indicate teaching was effective?

A. "I will have my therapeutic labs one time a year": Phenytoin has a narrow therapeutic range (10–20 mcg/mL) and requires regular monitoring. Checking levels only once a year is unsafe because toxicity or subtherapeutic dosing could be missed. B. "I will discontinue the drug immediately if any side effects occur": Abrupt discontinuation of phenytoin can trigger status epilepticus, a life-threatening complication. The client should notify the provider, but never stop the drug suddenly. C. "I will stop taking the medication once my seizures are under control": Seizure medications must be continued as prescribed. Stopping phenytoin independently increases the risk of recurrent seizures. D. "I will brush and floss my teeth twice a day, and visit dentist every 3–6 months": Phenytoin is associated with gingival hyperplasia. Good oral hygiene and regular dental care help prevent complications.