
Lubiprostone (Amitiza, Sucampo/Takeda) was approved on January 31, 2006, for the treatment of chronic idiopathic constipation in adults when the cause of the condition is unknown. The agent has a unique mechanism of action compared with current therapies on the market in that it locally activates specific chloride channels (ClC-2) in the lining of the small intestines after oral administration, thereby increasing intestinal fluids and softening bowel movements. In double-blind, placebo-controlled trials, lubiprostone demonstrated efficacy in improving the frequency of spontaneous bowel movements and other related constipation symptoms. Lubiprostone was reported to be well tolerated in clinical trials; the most common adverse effects were mild-to-moderate nausea and headache.