What is your approach to managing acidic urine in patients with recurrent uric acid nephrolithiasis who have normal urinary citrate levels?

After appropriate dietary advice from our Stone Clinic dietitian, I preferentially prescribe sodium bicarbonate tablets, teaching the patient how to adjust the dose using pH strip testing to reach the desired urinary pH. pH testing should be done frequently, as urine pH is in part dietary dependent and can change day to day. I avoid bicarbonate powder, as it is more likely to cause bloating than tablets. 

Stephen B. Erickson, MD

I agree with the general features of Dr. @Dr. First Last's approach. I frequently also advise patients to use calcium tablets with meals as a source of "dietary" calcium (1,000 to 1,500mg daily in divided doses), since many of these patients have a calcium oxalate fraction in their stones. The counter ion (carbonate or citrate or acetate) is an equivalent alkali load to sodium bicarbonate and spares the patient from adding protein from increased dairy intake. Protein catabolism, of course, is a major source of acid that the kidneys need to clear, which will drive the pH lower.