Question of the Week
For May 14, 2019
A 55-year-old man with a history of hypertension, hyperlipidemia, and non–small-cell lung cancer diagnosed one year ago is hospitalized with nausea, fatigue, poor appetite, and generalized weakness. His most recent staging CT scan showed progression of the lung cancer despite one year of chemotherapy.
On examination, his blood pressure is 110/60 mm Hg, and his heart rate is 95 beats per minute. He is alert and oriented but appears tired and has dry mucous membranes. He has diminished muscle strength in the upper and lower extremities.
A comparison of today’s laboratory findings with those from one month ago is as follows:
| Patient value one month ago | Current patient value | Reference range |
Calcium (mg/dL) | 9.5 | 12.3 | 9.0–10.5 |
Phosphorus (mg/dL) | 3.9 | 4.5 | 3.0–4.5 |
Albumin (g/dL) | 3.5 | 2.9 | 3.5–5.5 |
Blood urea nitrogen (mg/dL) | 14 | 47 | 10–20 |
Creatinine (mg/dL) | 0.9 | 1.6 | 0.8–1.3 |
The patient's current parathyroid hormone level is 5 pg/mL (reference range, 10–60); his 25-hydroxyvitamin D level is 32 ng/mL (30–80); and his 1,25-dihydroxyvitamin D level is 22 pg/mL (25–45).
After volume expansion with normal saline, which one of the following treatments is the most appropriate option for this patient?