Effects of Lubiprostone, an Intestinal Secretagogue, on Electrolyte Homeostasis in Chronic Idiopathic and Opioid-induced Constipation.

GOALS To assess short-term and long-term effects of lubiprostone, a type-2 chloride channel activator, on electrolyte homeostasis. BACKGROUND Conventional laxatives are associated with electrolyte imbalances. Lubiprostone is a type-2 chloride channel activator approved for treating chronic idiopathic constipation (CIC), opioid-induced constipation (OIC), and constipation-predominant irritable bowel syndrome in women. It induces intestinal fluid secretion, possibly affecting water and electrolyte homeostasis. We investigated short-term and long-term effects of lubiprostone on electrolyte, blood urea nitrogen (BUN), and creatinine levels using pooled data from CIC and OIC patients. STUDY Data were pooled from 10 CIC and OIC studies-6 double-blind, randomized, placebo-controlled studies and 4 open-label, long-term studies. Total duration of lubiprostone exposure was from 3 weeks (short-term: CIC, 3 to 4 wk; OIC, placebo-controlled, 12 wk) to 48 weeks (long-term: CIC, 24 to 48 wk; OIC, 48 wk). Sodium, chloride, potassium, magnesium, BUN, and creatinine levels were examined at baseline and final assessment. RESULTS Overall, 3209 patients were assessed. In the double-blind, placebo-controlled studies, there were no clinically meaningful differences in levels of electrolytes, BUN, and creatinine between lubiprostone and placebo groups, and in changes from baseline levels with long-term use of lubiprostone. Analyses of shifts in laboratory values (low/normal/high) at baseline and final assessment showed minimal effects on electrolytes, BUN, and creatinine. CONCLUSIONS Lubiprostone did not cause clinically meaningful electrolyte imbalances or affect markers of renal function in either the short-term or long-term treatment of CIC or OIC.