A nurse is educating a client who has been prescribed phenelzine, an MAOI, for treatment-resistant depression. Which of the following instructions is most critical to prevent potentially life-threatening complications associated with this medication?

Avoid foods high in tyramine, such as aged cheeses, smoked meats, and fermented products.

Use over-the-counter cold medications containing pseudoephedrine cautiously.

Take the medication with food to minimize gastrointestinal upset.

Avoid driving or operating heavy machinery until the effects are known.