A nurse is reinforcing teaching with a client who has a prescription for oral suspension phenytoin. Which of the following information should the nurse include in the teaching?

A. Phenytoin can rarely cause a side effect known as "purple glove syndrome" if it infiltrates into the surrounding tissues during intravenous administration, leading to discoloration. However, this is not relevant to oral suspension administration. B. Taking an antacid with phenytoin is generally not recommended as it may decrease the absorption of phenytoin. Phenytoin should be taken on an empty stomach to ensure optimal absorption. C. Phenytoin oral suspension may settle over time, so it's important to shake the bottle well before measuring and administering each dose to ensure uniform distribution of the medication. D. While obtaining an annual flu vaccine is generally advisable for individuals with epilepsy, it's not directly related to phenytoin administration and should be part of routine healthcare maintenance rather than specific guidance for phenytoin therapy.