What instruction should a nurse emphasize for a client taking methylprednisolone?

Monitoring blood glucose levels during therapy with methylprednisolone is essential because this corticosteroid can raise blood glucose levels, especially in patients with diabetes or those at risk of developing hyperglycemia. Corticosteroids like methylprednisolone increase gluconeogenesis and decrease glucose utilization in peripheral tissues, leading to elevated blood sugar levels. By emphasizing blood glucose monitoring, the nurse ensures that any significant changes can be identified and managed promptly, helping to prevent complications such as diabetes-related emergencies.

While the other options may relate to general medication safety practices with corticosteroids, they do not address the specific metabolic effects of methylprednisolone as closely as monitoring blood glucose does. For example, avoiding contact with people who have known infections is important due to the immunosuppressive effects of corticosteroids, but it does not cover the direct metabolic adjustments that need attention. Similarly, taking the medication at a specific time or adjusting potassium intake might be relevant for some patients, but they don't have the same critical connection to the immediate effects that could arise from the medication.