A nurse is conducting education for patients on drug and food combinations that can increase ...

B, C, E
The combination of theophylline and caffeine cause excitation when given concurrently; the combination of spironolactone and salt substitutes can cause very high potassium levels, which can affect the heart; grapefruit juice intensifies the effects of midazolam, resulting in increased sedation.
Lovastatin and grapefruit juice have interactions that result in increased blood levels of Mevacor; however, lovastatin and orange juice do not have this interaction. Maalox and grapefruit juice are not contraindicated and do not result in a drug and food interaction.

Very good answer