you are called by one of your patients, a 59-year-old woman with a history of breast cancer, metastatic to the lungs and bones, who has now developed confusion, lethargy, nausea, and vomiting. further questioning indicates that she also appears to have polyuria and constipation. she completed chemotherapy 6 weeks ago and since then has been on hormonal therapy. she was started on sustained release morphine sulfate and a nsaid one month ago because of worsening bone and back pain. based on this history, you decide to admit to her to the hospital. your initial workup and treatment are based on a suspected diagnosis of: