Problem
The nurse who is admitting the patient to the floor is taking a drug history. The patient lists his daily and as-needed medications and relates very detailed information. The nurse is surprised at the depth of information the patient provides about the medications. The nurse asks the patient if he has any questions. The patient asks, "I've always wanted to ask why the nurses ask if I drink grapefruit juice. Why is that such a big deal?" Explain why that is a problem to the patient and provide three examples of drugs whose metabolism would be affected if the patient drinks grapefruit juice and examples of other substances that can alter drug levels in the body.