What dietary instruction applies to a client taking cyclosporine?

The instruction to avoid grapefruit juice is crucial for a client taking cyclosporine because grapefruit juice can significantly affect the metabolism of this medication. Cyclosporine is metabolized primarily by the liver enzyme CYP3A4, and grapefruit juice can inhibit this enzyme. As a result, consuming grapefruit juice while on cyclosporine can lead to increased levels of the medication in the bloodstream, potentially causing toxic side effects. Therefore, avoiding grapefruit juice is an essential dietary instruction for ensuring the safety and efficacy of cyclosporine treatment.

The other dietary options do not have the same level of impact on cyclosporine metabolism or safety. High-fiber foods can be part of a healthy diet, potassium-rich foods are not typically contraindicated unless there are specific health concerns such as kidney problems, and while fruit juices can vary in their effects depending on the type, there are no overarching guidelines to avoid all fruit juices with cyclosporine. Thus, avoiding grapefruit juice is the most pertinent and vital dietary instruction for someone taking this medication.