The United States Food and Drug Administration approved Amitiza, the brand name for the drug lubiprostone, to treat chronic idiopathic constipation in 2006 and constipation-predominant irritable bowel syndrome, or IBS-C, in 2008. Amitiza remedies stomach pain, bloating and straining for some patients with these conditions by helping them have softer bowel movements that occur more frequently, often within 24 hours of starting the medication.
Approved Uses
The FDA approved Amitiza for use in adults with chronic idiopathic constipation which means constipation that lasts longer than three months and isn't caused by disease or another medication. The FDA also approved Amitiza for use in adult women who suffer from IBS-C, which is diagnosed on the basis of a three month history of abdominal pain accompanied by constipation. Although the manufacturer, Sucampo Pharmaceuticals, included men in the clinical trials for IBS-C, they accounted for less than eight percent of participants and the results failed to prove that the drug worked in men.
Safety
Pregnant women were intentionally excluded from clinical trials because animal reproduction studies showed fetal loss in guinea pigs--but not rats or rabbits---treated with the drug. Clinical trials in non-pregnant adults showed a high incidence of gastrointestinal side effects such as nausea---reported in 29 percent of patients---and diarrhea---reported in 12 percent of patients. However, in most cases, side effects resolve when patients take the drug with food or when doctors reduce the prescribed dose. Some patients---0.04%--also experience dyspnea, a sensation of chest tightness and difficulty breathing, that starts within 30 to 60 minutes of taking the drug and subsides in a few hours. Fortunately, dyspnea due to Amitiza, while uncomfortable and alarming, does not actually interfere with oxygenation. Unfortunately, it usually recurs.
Effectiveness
An April 2010 study published in the journal of "Digestive Diseases and Sciences" found that most patients who took Amitiza for chronic idiopathic constipation experienced relief within 24 hours of taking the drug. A 2009 review in the journal "Drugs" reported comparable findings among patients who took Amitiza for IBS-C and suggested that treatment effects may last even after the drug is discontinued among patients who complete a four week course. Amitiza has proven such an effective remedy for constipation that researchers are currently evaluating its use for constipation caused by other conditions such as cystic fibrosis and opioid pain management.
References
- FDA: Amitiza (Lubiprostone) Capsules
- MedlinePlus: Lubiprostone
- "Digestive Diseases and Sciences;" Efficacy and Safety of Lubiprostone in Patients with Chronic Constipation; C.F. Barish, D. Drossman, J.F. Johanson et al.; Apr. 2010
- "Drugs;" Lubiprostone in Constipation-Predominant Irritable Bowel Syndrome; N.J. Carter and L.J. Scott; June 2009
