MKSAP: 48-year-old man with urinary frequency

Test your medicine knowledge with the MKSAP challenge, in partnership with the American College of Physicians. A 48-year-old man is evaluated during a follow-up visit for urinary frequency. He reports no hesitancy, urgency, dysuria, or change in urine color. He has not experienced fevers, chills, sweats, nausea, vomiting, diarrhea, or other gastrointestinal symptoms. He feels thirsty very often; drinking water and using lemon drops seem to help. He has a 33-pack-year history of smoking. He has hypertension, chronic kidney disease, and bipolar disorder. Medications are amlodipine, lisinopril, and lithium. He has tried other agents in place of lithium for his bipolar disorder, but none has controlled his symptoms as well as lithium. Following a physical exam and lab results, what is the most appropriate treatment intervention for this patient? On physical examination, temperature is 37.3 °C (99.2 °F), blood pressure is 142/75 mm Hg, pulse rate is 82/min, and respiration rate is 14/min. BMI is 29. There are no rashes. There is no pitting edema of the extremities. Laboratory studies: Serum creatinine 1.9 mg/dL (168 µmol/L) Serum sodium 143 mEq/L (143 mmol/L) Urine osmolality 206 mOsm/kg H2O (normal range, 300-900 mOsm/kg H2O) Urinalysis Specific gravity 1.009; pH 5.5; trace protein; 0 erythrocytes/hpf; 0-2 leukocytes/hpf Urine cultures Negative Which of the following is the most appropriate treatment intervention for this patient? A: Amiloride B: Fluid restrict...
Source: Kevin, M.D. - Medical Weblog - Category: Journals (General) Authors: Tags: Conditions Medications Nephrology Source Type: blogs