Lubiprostone: pharmacokinetic, pharmacodynamic, safety and regulatory aspects in the treatment of constipation-predominant irritable bowel syndrome

INTRODUCTION: Lubiprostone acts locally (apical membrane of human intestinal epithelial cells) as a highly selective type-2 chloride channel activator. It was approved in the USA for chronic idiopathic constipation (January 2006) and in women aged ≥ 18 years suffering from irritable bowel syndrome with constipation (IBS-C) (April 2008). So far, the only other pro-secretory medication approved in IBS-C and currently available in USA and Europe (since August and November 2012, respectively) is linaclotide. AREAS COVERED: This review outlines the regulatory history, pharmacokinetic, pharmacodynamic and safety data in the treatment of IBS-C with a European perspective. It is based on publicly available data, namely, published literature, drug labels and the FDA's spontaneous reporting system. EXPERT OPINION: Although interesting pharmacodynamic data suggest that lubiprostone may have additional mechanisms of action, its beneficial effects in IBS-C must be confirmed in the actual clinical scenario taking into account the new version of European Medicines Agency's guideline. This is especially important with regard to duration of studies (recommended to be at least 6 months) to adequately assess long-term sustained efficacy, withdrawal, rebound and safety. Further research is warranted in uncertain areas (i.e., males, pediatric and elderly patients). On the basis of current data, it is still too early to draw definite conclusions on the overall risk-benefit balance for IBS-C.