Lubiprostone, a novel laxative, might improve hyperphosphatemia without water dilution

Hemodialysis patients often develop constipation due to dietary restriction and the use of phosphate and/or potassium binders. Lubiprostone is a novel laxative that promotes defecation by activating the chloride ion channel 2 (ClC-2) in the gastrointestinal tract. While lubiprostone has been reported to be useful in bowel control of dialysis patients, no studies have examined changes in electrolyte levels following administration of lubiprostone. We prospectively compared stool frequency and electrolyte levels before and after treatment with lubiprostone in 28 hemodialysis patients treated with the drug for at least 3 months in our hospital. Mean ± standard deviation of stool frequency was significantly increased from 1.8 ± 1.3 times/week before treatment to 4.3 ± 1.8 times/week at Month 1, 4.9 ± 1.9 times/week at Month 2, and 4.5±1.5 times/week at Month 3 (p < 0.001, p < 0.001, and p < 0.001, respectively). With regard to electrolyte levels, only serum inorganic phosphorus (IP) level was significantly decreased, from 4.7 ± 1.5 mg/dL at baseline to 4.5 ± 1.6 mg/dL at Month 1, 4.0 ± 1.3 mg/dL at Month 2, and 3.8 ± 1.1 mg/dL at Month 3 (p = 0.123, p < 0.001, and p < 0.001, respectively). Lubiprostone not only improved bowel control, but also decreased serum IP levels in hemodialysis patients. Lubiprostone may improve prognosis of hemodialysis patients through bowel control and a decrease in serum IP.