Lubiprostone: A chloride channel activator for treatment of chronic constipation

OBJECTIVE: To review lubiprostone's pharmacology, pharmacokinetics, efficacy, and safety in the treatment of chronic constipation. DATA SOURCES: A literature search was conducted using PubMed/MEDLINE (1966-January 2007), IngentaConnect, and International Pharmaceutical Abstracts (1977-January 2007). Key words used included lubiprostone, Amitiza, and chronic constipation. STUDY SELECTION AND DATA EXTRACTION: All articles identified from the data sources that were published in English were evaluated. DATA SYNTHESIS: Lubiprostone is a chloride channel activator approved by the Food and Drug Administration for the treatment of chronic constipation. A randomized, double-blind, parallel-group, placebo-controlled study evaluating the effect of lubiprostone on gastric function showed slowed gastric emptying and increased small bowel and colonic transit time. Peak plasma concentration was shown to be around 1.14 hours, with a majority of the drug excreted in the urine within 48 hours. Phase III trials have noted that most patients with chronic constipation have a spontaneous bowel movement within 24 hours after taking lubiprostone. The most common adverse events in these trials were nausea, diarrhea, abdominal pain, and headache. Lubiprostone use has not been studied in the pediatric population. CONCLUSIONS: Lubiprostone may be a reasonable alternative for use in patients who either fail or are intolerant of standard therapy for chronic constipation. Head-to-head comparison studies with conventional therapy are needed to contrast clinical efficacy and safety of this medication.