Final answer:
The nurse should instruct the client on prednisone to prioritize reporting any abdominal pain or dark-colored vomit, as these can indicate serious complications.
Step-by-step explanation:
The highest priority instruction a nurse will provide to a client who has recently been placed on prednisone (Deltasone) is to report any abdominal pain or dark-colored vomit. Prednisone is a glucocorticoid used to reduce inflammation in conditions such as Crohn's disease, asthma, and arthritis. However, its immunosuppressive effects can increase the risk of infections and gastrointestinal bleeding, which is indicated by symptoms such as abdominal pain or dark-colored vomit. Both are signs of potential serious complications. Taking the drug with food or milk can help to reduce gastrointestinal distress, watching one's diet is important to prevent exacerbating the condition, and expecting to experience weight gain is part of managing side effects, but the immediate report of severe abdominal symptoms is a critical safety concern.