What food item should a client prescribed cyclosporine (Sandimmune) avoid?

The correct choice is grapefruit juice, which individuals taking cyclosporine should avoid due to its potential to interact with the medication. Grapefruit juice contains compounds that inhibit the cytochrome P450 3A4 enzyme system in the liver, which plays a crucial role in the metabolism of many drugs, including cyclosporine. When this enzyme is inhibited, it can lead to increased levels of cyclosporine in the bloodstream. This heightened concentration can elevate the risk of toxicity and adverse effects, as the body may not effectively clear the drug at the usual rate.

The need to avoid grapefruit juice is particularly important because it affects how cyclosporine is metabolized, creating a scenario where the intended therapeutic effects could become dangerous if not monitored carefully. Other dietary items, such as red meats, orange juice, and green leafy vegetables, do not have the same impact on the metabolism of cyclosporine and are generally considered safe for consumption alongside the medication.