Some time ago, I was consulted on a patient because of excessive urination. The patent was putting out 4 or 5 five liters a day and nobody knew why. I checked out all the usual suspects, diabetic ketoacidosis, hyperglycemia, diabetes insipidus, etc. and all the medications listed on his chart. No diuretics. Finally, at my wit’s end, I entered the ICU room and noticed a number of med bags, some full, some empty hanging there on the IV pole. I checked each and discovered a bag labeled "dopamine” slowly dripping in.
I went to the nurse and asked how long the patient had been on dopamine. She said "He's not on dopamine." I said, "Come with me" and showed her that he was in fact getting low dose dopamine, a drug that behaves like a diuretic.